Evaluación de la formación de biopelículas en aislamientos bacterianos y fúngicos por el método semicuantitativo de microtitulación con cristal violeta y el cualitativo de agar con rojo Congo / Assessment of biofilms formation of bacterial and fungal isolates using qualitative Congo red agar and semiquantitative crystal violet microtiter methods

Introducción. El 65 % de las infecciones humanas son producidas por bacterias o levaduras, cuya capacidad de formar biopelículas las hace más resistentes a los antimicrobianos y antifúngicos. Objetivo. Determinar la capacidad de formación de biopelículas en aislamientos bacterianos y fúngicos por medio de los métodos cuantitativo de microtitulación con cristal violeta y cualitativo de cultivo en agar con rojo Congo. Materiales y métodos. Con el método cuantitativo, se utilizaron los medios de cultivo infusión cerebro-corazón, tripticasa de soya y Müeller-Hinton para aislamientos bacterianos; para levaduras, se usaron caldo infusión cerebro-corazón y Sabouraud dextrosa. Para el método cualitativo de cultivo en agar, se utilizaron los mismos medios de cultivo más una solución con 3 % de rojo Congo y 10 % de dextrosa. Cómo método de referencia, se utilizó la propuesta de Stepanovic et al. Resultados. Se evaluaron 103 aislamientos bacterianos y 108 de levaduras. No es recomendable sustituir el caldo infusión cerebro-corazón por los caldos tripticasa de soya y Müeller-Hinton en el método cuantitativo, para evaluar la formación de biopelículas en los aislamientos bacterianos. El medio Sabouraud dextrosa, en caldo y agar, puede sustituir al de infusión de cerebro-corazón para evaluar la formación de biopelículas en levaduras, tanto por el método cuantitativo como por el cualitativo. Conclusión. El estudio de las biopelículas en el laboratorio de microbiología, a partir del método cualitativo de cultivo en agar con rojo Congo, es un procedimiento sencillo, rápido y de bajo costo, que proporciona información útil para el diagnóstico y la terapéutica de infecciones persistentes causadas por bacterias y levaduras.

Introduction. Sixty-five percent of human infections are caused by bacteria or yeasts able to form biofilms. This feature makes them more resistant to antimicrobials and antifungals. Objective. To determine biofilm formation capacity of bacterial and fungal isolates by quantitative crystal violet microtiter and qualitative Congo red agar methods. Materials and methods. Brain-heart infusion, trypticase soy broth and Müeller-Hinton culture media were used in bacterial isolates for the quantitative method; brain-heart infusion broth and Sabouraud dextrose were used for yeasts. The same culture media plus 3% Congo red and 10% dextrose were used to apply the qualitative method in agar. The proposal by Stepanovic, et al. was used as a reference method. Results. We evaluated 103 bacterial isolates and 108 yeasts isolates. We did not recommend substitute brain-heart infusion broth for trypticase soy and Müeller-Hinton broths for biofilm formation assessment in bacterial isolates using the quantitative method. Sabouraud dextrose medium, both broth and agar, can replace brain-heart infusion to assess biofilm formation in yeasts, quantitatively and qualitatively. Conclusion. The study of biofilms in the microbiology laboratory, using Congo red agar qualitative method, is a simple, fast, and inexpensive procedure that provides precise information for the diagnosis and treatment of persistent infections caused by bacteria and yeasts.

Empiema pleural por Parvimonas micra en un paciente inmunocompetente: reporte de un caso / Pleural empyema by Parvimonas micra in an immunocompetent patient: a case report

Se presenta el caso de un paciente joven inmunocompetente, con antecedente de tuberculosis pulmonar, que acude al hospital por un cuadro clínico subagudo de fiebre persistente, baja de peso, disnea y abolición del murmullo vesicular. La tomografía de tórax mostró un extenso empiema en hemitórax izquierdo. Se le toman muestras para detección de gérmenes comunes y se le colocan un tubo de drenaje torácico y se inicia antibioticoterapia. La prueba de MALDI-TOF MS identificó a Parvimonas micra, una bacteria anaerobia, comensal de la flora oral, asociado a periodontitis severa, escasamente reportado en empiema pleural, especialmente, en personas inmunocompetentes. En la evaluación odontológica se realizó el diagnóstico de gingivitis y pericoronaritis de la tercera molar. El paciente evolucionó favorablemente. Se sugiere que, en casos de empiemas pleurales subagudos o crónicos, se debe considerar, además de las micobacterias, como agente etiológico al Parvimonas micra, y optar por exámenes como MALDI-TOF MS o secuenciamiento del 16S rRNA, colocación de tubo de tórax, cobertura antibiótica empírica y evaluación odontológica.

We present the case of a young immunocompetent patient, with a history of pulmonary tuberculosis, who attended the hospital with a subacute clinical picture of persistent fever, weight loss, dyspnea and abolition of vesicular murmur. Chest CT scan showed an extensive empyema in the left hemithorax. Samples were taken for detection of common germs. Then, a chest drainage tube was placed and antibiotic therapy started. The MALDI-TOF MS test identified Parvimonas micra, an anaerobic bacterium, commensal to the oral flora, associated with severe periodontitis, but rarely reported in cases of pleural empyema, especially in immunocompetent patients. Gingivitis and pericoronaritis of the third molar were diagnosed during oral evaluation. The patient progressed favorably. Parvimonas micra should be considered as a possible etiological agent in cases of subacute or chronic pleural empyema, in addition to mycobacteria. Tests such as MALDI-TOF MS or 16S rRNA sequencing, chest tube placement, empirical antibiotic coverage and an adequate oral evaluation should be considered in these cases.

Distribution and drug resistance of pathogenic bacteria of biliary tract infection in patients subjected to hepatobiliary surgery / 中国基层医药

Objective:To study the distribution and drug resistance of pathogenic bacteria of biliary tract infection in patients with hepatobiliary surgery.Methods:A total of 103 patients with biliary tract infection who received treatment in the Department of Hepatobiliary Surgery, Lanxi People's Hospital from May 2020 to October 2022 were included in this study. Their bile was cultured to analyze the distribution and drug resistance of pathogenic bacteria. The data were processed using the WHONET5.5 software system.Results:Fifty-eight pathogenic bacteria-positive samples were cultured from the bile of 103 patients with biliary tract infection, with a pathogenic bacteria-positive rate of 56.31%. Among 58 strains of pathogenic bacteria, 38 strains (65.52%) were gram-negative bacteria, mainly Escherichia coli and Klebsiella pneumonia, and 5 strains (8.62%) were fungal strains. Escherichia coli and Klebsiella pneumoniae were highly resistant to sulfamethoxazole-trimethoprim, ciprofloxacin, and other antibacterial drugs, and were completely sensitive to imipenem and meropenem. Enterococcus faecalis was mainly resistant to ampicillin and penicillin G,and it was completely sensitive to vancomycin and teicoplanin. Staphylococcus aureus was resistant to vancomycin, ciprofloxacin, cefotaxime, and other drugs. A total of 13 strains of ultrabroad-spectrum beta-lactamase bacteria were isolated from 25 strains of Escherichia coli and 7 strains of Klebsiella pneumonia, with the positive detection rate of 40.63%. Conclusion:The main pathogenic bacteria of biliary tract infection are Gram-negative bacteria, which are widely distributed and have serious drug resistance. In clinical practice, antimicrobial drugs should be reasonably selected according to the results of bile drug sensitivity tests.

BRICS report of 2021: The distribution and antimicrobial resistance profile of clinical bacterial isolates from blood stream infections in China / 中华临床感染病杂志

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Distribution and drug resistance characteristics of pathogens in recipients undergoing simultaneous pancreas-kidney transplantation / 器官移植

Objective To investigate the distribution and drug resistance characteristics of pathogens in donors and recipients undergoing simultaneous pancreas-kidney transplantation (SPK). Methods Clinical data of 231 pairs of donors and recipients undergoing SPK were analyzed retrospectively. The pathogens of samples from donors and recipients were identified by VITEK-2 analyzer, and drug sensitivity test was performed by K-B method. The source distribution and composition ratio of pathogens in donor and recipient samples, distribution characteristics of multi-drug resistant organism, infection of recipients and drug resistance characteristics of pathogens were analyzed. Results A total of 395 strains of pathogens were cultured from 1 294 donor samples, and the detection rate was 30.53%. Gram-negative bacteria mainly consisted of klebsiella pneumoniae, Gram-positive bacteria mainly comprised staphylococcus aureus, and fungi primarily included candida albicans, respectively. In total, 2 690 strains of pathogens were cultured from 10 507 recipient samples, and the detection rate was 25.60%. Gram-negative bacteria mainly consisted of pseudomonas maltophilia, Gram-positive bacteria primarily comprised enterococcus faecalis, and fungi mainly included candida albicans, respectively. Among 395 pathogens of donors, 15 strains of methicillin-resistant staphylococcus aureus (MRSA), 16 strains of extended-spectrum β-lactamase (ESBL) positive drug-resistant bacteria, 8 strains of carbapenem-resistant pseudomonas aeruginosa (CR-PA), 21 strains of carbapenem-resistant acinetobacter baumannii (CR-AB), 2 strains of carbapenem-resistant enterobacteriaceae (CRE) and 1 strain of multiple-drug/pan-drug resistant pseudomonas aeruginosa (MDR/PDR-PA) were identified. Among 2 690 strains of recipient pathogens, 73 strains of ESBL positive drug-resistant bacteria, 44 strains of CR-PA, 31 strains of CR-AB and 3 strains of MDR/PDR-PA were detected. One recipient developed donor-derived infection, 69 cases of pneumonia, 52 cases of urinary tract infection, 35 cases of abdominal infection and 2 cases of hematogenous infection were reported within postoperative 1 year. Gram-negative bacteria were resistant to certain antibiotics. Gram-positive bacteria were sensitive to vancomycin. Fungi were sensitive to amphotericin B. Conclusions Gram-negative bacteria are the main pathogens of SPK recipients, which are resistant to certain antibiotics. Empirical use of antibiotics can be delivered before culture results are obtained. Subsequently, sensitive antibiotics should be chosen according to the culture results to improve the survival rate of SPK recipients.

Homeopathic medicine activity on the growth of Gram-negative bacteria

Homeopathy is a therapy that uses medications prepared with infinitesimal and dynamized dilutions. Current studies demonstrate in vitro activity of homeopathy on gram-positive bacteria such as Staphylococcus aureusand Streptococcus pyogenes. Among bacterial infections, urinary tract infection (UTI) is frequent, leads to later consequences and the main causal agent is Escherichia coli(E. coli). In other publications, it has been reported inactivity of homeopathy on E. colicultures. Due to the divergence in the literature, the objective of this study was to evaluate gram-negative bacteria growth under homeopathy treatment. Methods:The medicines Atropabelladona, Cantharis, Staphysagria,and Colibacillinumwere tested at 6CH, 12CH and 30CH inE. coliATCC 25922 and EPEC (Enteropathogenic Escherichia coli) ATCC 43887. Two hundred and fifty microliters of the medicines in alcohol 30% were incubated at 37ºC with 3 mL of Müller Hinton broth (MH), 10 µL of cultures at 0.5 Macfarland and subsequent dilution at 1/10. Bacterial growth was evaluated in a spectrophotometer at 600nm, in the periods of 6, 12,and 20 hours of incubation. Resultsand Discussion:The results showed no inhibition of bacterial growth under the studied conditions. These data corroborate with studies already published that indicate the absence of action of homeopathy on E. colicultures. Considering other studies, it can be suggested that homeopathic medicines have direct activity on the growth of Gram-positive and not Gram-negative bacteria. Evaluating the two bacterial groups, it is possible to assume that the difference in homeopathy activity could be linked to differences in the bacterial wall structure. This hypothesis should be evaluated by other tests with the same bacterialstrains. Conclusion:The homeopathic medicines tested have no direct activity on Gram-negative bacteria cultures.

Análisis comparativo de la actividad antimicrobiana de secreciones y excreciones larvarias de Calliphora vicina y Sarconesiopsis magellanica (Diptera: Calliphoridae) / A comparative analysis of Calliphora vicina and Sarconesiopsis magellanica (Diptera: Calliphoridae) larval secretions and excretions antimicrobial activity

Introducción. La creciente resistencia bacteriana a los antibióticos representa una amenaza mundial de salud pública. Las excreciones y secreciones larvarias derivadas de moscas necrófagas de la familia Calliphoridae podrían configurar una fuente promisoria para contrarrestar sus efectos. Objetivo. Comparar la actividad antimicrobiana de las excreciones y secreciones larvarias nativas, y de las mayores y menores de 10 kDa de Calliphora vicina y Sarconesiopsis magellanica (Diptera: Calliphoridae). Materiales y métodos. El bioensayo se hizo a partir de la técnica de turbidimetría y en el caso de las excreciones y secreciones menores de 10 kDa se determinó la concentración inhibitoria mínima (CIM). Resultados. Las excreciones y secreciones nativas y las menores de 10 kDa de C. vicina y S. magellanica, evidenciaron una potente actividad antibacteriana contra tres cepas de Staphylococcus aureus y cuatro bacterias Gram negativas, siendo las menores de 10 kDa más efectivas que las nativas en las dos especies de moscas evaluadas. Además, las menores de 10 kDa presentaron la misma efectividad, aunque en las pruebas de CIM se observó que las de S. magellanica fueron más potentes en todas las bacterias evaluadas, excepto contra la cepa de S. aureus ATCC 25923. Las mayores de 10 kDa no inhibieron el crecimiento bacteriano. Conclusión. Los resultados validaron, en general, que estas sustancias son fuente importante para el aislamiento y la caracterización de agentes antimicrobianos.

Introduction: The growing resistance to antibiotics worldwide represents a global threat to public health. The larval excretions and secretions derived from necrophagous flies from the Calliphoridae family could represent a promising source for counteracting their effects. Objective: To compare the antimicrobial activity of Calliphora vicina and Sarconesiopsis magellanica (Diptera: Calliphoridae) native excretions and secretions and those weighing more than 10 kDa and less. Materials and methods: We used the turbidimetry technique for the bioassay; we determined the minimum inhibitory concentration (MIC) for excretions and secretions weighing less than 10 kDa. Results: Calliphora vicina and S. magellanica native excretions and secretions and those weighing less than 10 kDa exhibited potent antibacterial activity against three Staphylococcus aureus strains and four Gram-negative bacteria; those weighing less than 10 kDa were more effective than the native ones in the two species of flies evaluated here. Furthermore, excretions and secretions weighing less than 10 kDa had the same effectiveness, except in the MIC trials where S. magellanica excretions and secretions weighing less than 10 kDa were more potent against all the bacteria evaluated, except for S. aureus ATCC 25923. Excretions and secretions weighing more than 10 kDa did not inhibit bacterial growth. Conclusions: These results potentially validate these substances as an important source for isolating and characterizing antimicrobial agents.

The extracellular vesicles from gram-positive bacteria: a review / 生物工程学报

Extracellular vesicles (EVs), also known as membrane vesicles, are vesicular bodies secreted by eukaryotic cells and bacteria. EVs can carry proteins, DNA, RNA, and various metabolites for the exchange and transmission of substances between cells. They play contents-dependent physiological functions, such as delivering nutrients, participating in immune response, and treating cancers. Currently, most studies focus on the exploration of vesicles secreted by eukaryotic cells and gram-negative bacteria, while few studies focus on gram-positive bacteria. This review summarized the production, content composition, physiological function, and engineering of EVs secreted by gram-positive bacteria, and prospected future perspectives in this area.

The potential use of papaya and banana peels as substrate to enhance the pigment production of Gram-positive bacterial strain isolated from Holothuria (Lessonothuria) pardalis

Aims@#The microbial pigment can be the best promising alternative to replace synthetic colorant. However, due to the high cost of synthetic medium for microbial pigment production, there is a need to develop a new low-cost medium of bacterial pigment production. This study aims to investigate the potential of banana and papaya peels as alternative lowcost substrates for a carotenoid-producing bacterium, B12 strain (bacteria strain isolated from Holothuria (Lessonothuria) pardalis).@*Methodology and results@#B12 strain identified as an aerobic bacterium with non-motile, diplobacilli shaped and Grampositive bacteria. The fermentation was optimized with different parameters included the effect of temperature, time, concentrations, pHs, carbon and nitrogen sources to find the optimum relative pigment concentration produced by B12. The results showed that the B12 strain produced the highest relative pigment concentration measured at 450 nm when the strain was cultivated at 37 °C and pH 7 in the culture medium incorporated with the combination of dried papaya peels and banana peels (100% v/v with ratio 1:1) at 72 h of incubation. Lactose, peptone and yeast were observed as the best carbon and nitrogen sources to increase the pigment concentration of B12 strain. Stability of the pigment was studied at different physiochemical stress, and it showed the pigment obtained from dried papaya and banana substrates can tolerate and stable under stress condition.@*Conclusion, significance and impact of study@#This can be concluded that the combination of dried papaya and banana peels worked well as substrate and can be utilized as a fermentation medium to replace the synthetic medium which is more expensive and uneconomical for industry application. Besides, it also helps in managing waste and solving the pollution problem due to the increasing of biochemical oxygen demand (BOD) and chemical oxygen demand (COD).

Analysis of clinical characteristics and risk factors of influenza virus complicated with gram-positive bacterial infection in children / 中国小儿急救医学

Objective:To explore the clinical characteristics and risk factors of influenza virus complicated with gram-positive bacterial infection in children.Methods:The clinical data of children with influenza virus complicated with gram-positive bacterial infection hospitalized at Shenzhen Children′s Hospital affiliated to China Medical University from January 2013 to December 2019 (observation group) were retrospectively studied.During the same period, 110 hospitalized children with influenza virus infection without co-infection were selected as the control group.The clinical data of the children in two groups were analyzed.Logistic regression analysis was used to analyze the risk factors of influenza virus complicated with gram-positive bacterial infection.Results:There were 108 children in the observation group, including 68 boys and 40 girls, with the age of(2.6±1.8)years, and 100(92.6%) children under 5 years old.Incidence month distribution: 61 cases from January to March, 15 cases from April to June, 13 cases from July to September, and 19 cases from October to December.In the observation group, 73 cases were infected with influenza A virus, 35 cases were infected with influenza B virus, 94(87.0%)cases were complicated with Streptococcus pneumoniae infection, 11 cases with Group A Streptococcus infection and 8 cases with Staphylococcus aureus infection.And 15 (13.9%) cases had underlying diseases.None of the patients in the observation group received pneumococcal conjugate vaccine, and two cases received influenza vaccine within one year.There were 110 children in the control group, including 57 boys and 53 girls, with the age of (5.0±2.4)years old.There were 80 cases of influenza A virus infection and 30 cases of influenza B virus infection.Four cases had underlying diseases, six cases received 13-valent pneumococcal conjugate vaccine and 12 cases received influenza vaccine within one year.Compared with the control group, the children in the observation group were younger[(2.6±1.8)years vs.(5.0±2.4) years, χ2=-7.935, P<0.001], had more underlying diseases[13.9%(15/108)vs.3.6%(4/110), χ2=7.200, P=0.007], less proportion of influenza vaccine[1.9%(2/108)vs.10.9%(12/110), χ2=7.439, P=0.006], the hospitalization time was longer[6(5, 7)d vs.4(3, 5)d, Z=-7.278, P<0.001], and mone cases of first use of neuraminidase inhibitors(NAI) for more than 48 hours[75.9%(82/108)vs.14.5%(16/110), χ2=82.971, P<0.001]. In the observation group, there were 97 culture-positive specimens of Streptococcus pneumoniae, including 89 of sputum/bronchoalveolar lavage fluid, five of blood culture and three of cerebrospinal fluid.All Streptococcus pneumoniae were resistant to erythromycin and clindamycin; the resistance rates of non-meningitis Streptococcus pneumoniae to ceftriaxone, cefotaxime and penicillin were 7.7%, 5.5% and 1.1%, respectively, and all the strains were sensitive to vancomycin, linezolid and levofloxacin.All patients in the observation group were treated with NAI and antibiotics, 37 cases were treated with bronchoalveolar lavage, 27 cases were admitted to pediatric intensive care unit, 10 cases were treated by non-invasive continuous positive airway pressure ventilation, and 17 cases received mechanical ventilation; 6 cases died.Logistic regression analysis showed that underlying diseases, unvaccinated with influenza and (or) pneumococcal vaccine, and the first use of NAI>48 hours were risk factors for influenza virus complicated with gram-positive bacterial infection. Conclusion:Influenza virus complicated with gram-positive bacterial infection can aggravate the illness and even death of children.Early identification of gram-positive bacterial infection, timely treatment of NAI and antibiotics, and active control of complications could be helpful to improve the cure rate.Strengthening influenza and pneumococcal vaccine during flu season can help reduce infection.

Differences in organ dysfunction between gram-positive and gram-negative bacteria-induced sepsis in rats / 中华麻醉学杂志

Objective:To evaluate the differences in organ dysfunction between gram-positive and gram-negative bacteria-induced sepsis in rats.Methods:Fifty-two adult male Sprague-Dawley rats, weighing 340-380 g, aged 15-18 weeks, were divided into 3 groups using a random number table method: control group (C group, n=12), G - bacteria group ( n=20), and G + bacteria group ( n=20). The G + and G - septic models were developed by intraperitoneal injection of inactivated Staphylococcus aureus and Escherichia coli suspension in G + and G - bacteria groups, respectively.The survival status within 36 h after injection of inactivated bacteria was recorded.Mean arterial pressure (MAP), platelet count (Plt), oxygenation index (OI) and serum concentrations of tumor necrosis factor α (TNF-α), cardiac troponin T (cTnT), total bilirubin (TBIL), creatinine (Cr), neuron-specific enolase (NSE) and lactic acid (Lac) were measured at 6, 12, 24 and 36 h after injection of inactivated bacteria.Fear conditioning test and open field test were performed at 12 and 36 h after injection of inactivated bacteria.The apoptosis rate of neurons in hippocampal CA1 area was measured by TUNEL, and the permeability of blood-brain barrier was measured by Evans blue method.The histopathological changes of lung, heart, kidney and brain tissues were examined at 36 h after injection of inactivated bacteria. Results:Compared with C group, the number of crossing grids and percentage of time spent freezing were significantly decreased, the apoptosis rate of neurons and permeability of blood-brain barrier were increased, and the survival rate was decreased in G - bacteria group and G + bacteria group ( P<0.05); the serum TNF-α concentration was significantly increased in G + bacteria group, and the serum cocentration of OI was significantly decreased, and the serum concentrations of cTnT, Cr, TNF-α and Lac were increased in G - bacteria group at 6 h after injection of inactivated bacteria ( P<0.05); the serum concentrations of cTnT, Cr, NSE, TNF-α and Lac in G + bacteria group and serum concentrations of cTnT, Cr, TNF-α and Lac in G - bacteria group were increased, and the OI, MAP and Plt were decreased at 12 h after injection of inactivated bacteria in both groups ( P<0.05); the serum concentrations of cTnT, TBIL, Cr, NSE, TNF-α and Lac were increased, and OI, MAP and Plt were decreased at 24 and 36 h after injection of inactivated bacteria in G + bacteria group and G - bacteria group ( P<0.05). Compared with G + bacteria group, the serum concentrations of TNF-α and cTnT and apoptosis rate of neurons were significantly decreased at 12 h after injection ( P<0.05); the serum concentrations of TNF-α and Lac were significantly increased, the serum concentrations of cTnT, OI, MAP and Plt were decreased at 24 h after injection of inactivated bacteria ( P<0.05); the serum concentrations of Cr, NSE, TNF-α and Lac were significantly increased, OI, MAP and Plt were decreased, and the percentage of time spent freezing, apoptosis rate of neurons and permeability of blood-brain barrier were increased at 36 h after injection of inactivated bacteria in G - bacteria group ( P<0.05). Conclusions:Early respiratory dysfunction and multiple organ failure often occur in G - bacteria sepsis, while G + bacteria sepsis is more likely to cause early circulatory and neurological dysfunction, and G - sepsis presents with more serious organ damage and high fatality rate as the disease progresses.

Bacteremia after Bacillus clausii administration for the treatment of acute diarrhea: A case report / Bacteriemia tras la administración de Bacillus clausii para el tratamiento de la diarrea aguda: reporte de un caso

Abstract | Bacillus clausii is a gram-positive rod used as a probiotic to treat diarrhea and the side effects of antibiotics such as pseudomembranous colitis. We report a case of B. clausii bacteremia in a non-immunocompromised patient with active peptic ulcer disease and acute diarrhea. The probiotic was administered during the patient's hospitalization due to diarrhea of infectious origin. B. clausii was identified in the bloodstream of the patient through Matrix- Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) days after her discharge. Given the wide use of probiotics, we alert clinicians to consider this microorganism as a causative agent when signs of systemic infection, metabolic compromise, and hemodynamic instability establish after its administration and no pathogens have been identified that could explain the clinical course.

Resumen | Bacillus clausii es un bacilo Gram positivo usado como probiótico para tratar la diarrea y efectos adversos de los antibióticos, como la colitis pseudomembranosa. Se reporta un caso de bacteriemia por B. clausii en una paciente inmunocompetente con enfermedad ulcerosa péptica activa y diarrea aguda. El probiótico le fue administrado durante la hospitalización debido al origen infeccioso de la diarrea. B. clausii se identificó en el torrente sanguíneo de la paciente, utilizando espectrometría de desorción/ionización mediante láser asistido por matriz (Matrix-Assisted Laser Desorption/Ionization, MALDI), acoplada a un detector de iones (Time of Flight, TOF) (MALDI-TOF), días después de haber sido dada de alta. Dado el amplio uso de los probióticos, alertamos a los clínicos para que consideren este microorganismo como agente causal cuando se detecten signos de infección sistémica, compromiso metabólico, e inestabilidad hemodinámica tras su administración, y no se haya identificado ningún patógeno que pueda explicar el cuadro clínico.

An unexpected pathogen causing multiple intra-abdominal abscesses in an immunocompetent patient / Un patógeno inesperado como causa de múltiples abscesos intrabdominales en un paciente inmunocompetente

Abstract Streptococcus constellatus is a member of the group now called Streptococcus anginosus. This microorganism is part of the normal oropharyngeal, gastrointestinal and genitourinary microbiota. However, it may cause serious infections such as pharyngitis, bacteremia and invasive pyogenic infections in immunocompromised patients. We report the first case in Colombia of an adult male with no relevant medical history and with an unusual presentation of infection by S. constellatus and whose laboratory results showed an important systemic inflammatory response and radiographic evidence of abdominal involvement with poor response to medical and surgical management. Since there are few reports in international medical journals about intra-abdominal infection by S. constellatus and taking into consideration the need of a multidisciplinary intervention, this report may be of interest for both clinical and surgical practitioners.

Resumen Streptococcus constellatus es un miembro del grupo ahora llamado Streptococcus anginosus. Este microorganismo es parte de la microbiota orofaríngea, gastrointestinal y genitourinaria normal. Sin embargo, puede causar infecciones graves como faringitis, bacteriemia e infecciones piógenas invasivas en pacientes inmunocomprometidos. Presentamos el primer caso en Colombia de un hombre adulto sin antecedentes médicos relevantes y con una presentación inusual de infección por S. constellatus, dada por una gran respuesta inflamatoria sistémica y evidencia radiográfica de afectación abdominal con mala respuesta al tratamiento médico y quirúrgico. Dado que hay pocos informes en revistas médicas internacionales sobre la infección intraabdominal por S. constellatus y teniendo en cuenta la necesidad de intervenciones multidisciplinarias, este reporte puede ser de interés tanto para los médicos clínicos como para los quirúrgicos.

Factores pronósticos de mortalidad por agente infeccioso en un hospital de alta complejidad de Cartagena-Colombia / Prognostic factors for mortality caused by an infectious agent in a high complexity hospital in Cartagena-Colombia

Introducción: La identificación de los principales factores clínico-epidemiológicos que determinan causas de mortalidad en pacientes hospitalizados es una necesidad apremiante, principalmente cuando los esfuerzos realizados en la actualidad no permiten asumir acciones fundamentadas en la identificación de las causas de dicho evento. Objetivo: Establecer cuáles son los factores pronósticos de mortalidad por agente infeccioso en un hospital de alta complejidad de la ciudad de Cartagena- Colombia. Material y Métodos: Se realizó un estudio de casos y controles retrospectivo, con muestra proyectada de 86 casos y 258 controles, en una relación 1:3, que cumplieron con los criterios de elegibilidad respectivos y en los que realizaron análisis bivariados y posteriormente un análisis multivariado que incluyó métodos de regresión logística binaria. Resultados: El riesgo de mortalidad en el análisis multivariado está determinado por variables como sexo masculino (ORa 1,695 IC 95 por ciento: 1,005-2,856); Cáncer (ORa 2,389 IC 95 por ciento 1,230-4,642); inmunosupresión (ORa 3,211 IC 95 por ciento 1,004-10,26); Ventilación mecánica (ORa 2,541 IC 95 por ciento 1,128-5,722); Estancia en la UCI (ORa 2,331 IC 95 por ciento1,227-4,425) e Infección por bacterias productoras de carbapenemasas (ORa 4,778 IC95 por ciento 1,313-17,38). Conclusiones: En pacientes masculinos con cáncer o cualquier otra forma de inmunosupresión, en los que se requiera el uso del ventilador mecánico o estancia en la unidad de cuidado intensivo y que además desarrollen infecciones por bacterias productoras de carbapenemasas existe mayor riesgo de muerte por agente infeccioso(AU)

Introduction: The identification of the main epidemiological clinical factors that determine the causes of mortality in hospitalized patients is a pressing need, mainly when the efforts made at present do not allow us to take actions based on the identification of the causes of the aforementioned event. Objective: To identify the prognostic factors for mortality caused by infectious agents in a high complexity hospital in the city of Cartagena, Colombia. Material and Methods: A retrospective case-control study was conducted in 86 cases and 258 control samples that met the eligibility criteria, at the 1: 3 ratio. Bivariate analyses and a subsequent multivariate analysis that included binary logistic regression methods were also performed. Results: In the multivariate analysis, the risk of mortality is determined by variables such as male sex (ORa 1,695 95 percent CI: 1.005-2.856); cancer (ORa 2,389 95 percent CI 1,230-4,642); immunosuppression (ORa 3.211 95 percent CI 1.004-10.26); mechanical ventilation (ORa 2.541 95 percent CI 1.128-5.722); stay in the ICU (ORa 2,331 95 percent CI 1,227-4,425) and infection caused by carbapenemase-producing bacteria (ORa 4,778 95 percent CI 1,313-17.38). Conclusions: Male patients with cancer or any other form of immunosuppression who require the use of a mechanical ventilator or admission to the intensive care unit who also develop infections caused by carbapenemase-producing bacteria, are at greater risk of death from an infectious agent(AU)

Risk factors of multi-drug resistant organism infection after liver transplantation: a single-center clinical trial / 器官移植

Objective To analyze the risk factors of multi-drug resistant organism (MDRO) infection after liver transplantation. Methods The clinical data of 77 recipients undergoing liver transplantation were retrospectively analyzed. According to the incidence of MDRO infection, all recipients were divided into the non-MDRO infection group (n=51) and MDRO infection group (n=26). The infection rate and strain distribution of MDRO in liver transplant recipients were summarized. The risk factors of MDRO infection in liver transplant recipients were identified. Clinical prognosis of all recipients was statistically compared between two groups. Results The infection rate of MDRO after liver transplantation was 34% (26/77), mainly carbapenem-resistant MDRO infection. The main sites of infection included lung, abdominal cavity and incision. Univariate analysis showed that postoperative tracheal intubation ≥48 h, length of intensive care unit (ICU) stay ≥72 h, length of hospital stay ≥30 d, re-operation, continuous renal replacement therapy (CRRT) and tacrolimus (Tac) blood concentration ≥15 ng/mL were the risk factors for MDRO infection after liver transplantation. Cox regression analysis indicated that postoperative tracheal intubation≥48 h, re-operation, CRRT and Tac blood concentration ≥15 ng/mL were the independent risk factors for MDRO infection after liver transplantation. The fatality in the MDRO infection group was significantly higher than that in the non-MDRO infection group [31%(8/26) vs. 10%(5/51), P=0.01]. Conclusions Postoperative tracheal intubation ≥48 h, re-operation, CRRT and Tac blood concentration ≥15 ng/mL may increase the risk of MDRO infection after liver transplantation and affect clinical prognosis of the recipients.

BRICS report of 2020: The bacterial composition and antimicrobial resistance profile of clinical isolates from bloodstream infections in China / 中华临床感染病杂志

Objective:To investigate the bacterial composition and antimicrobial resistance profile of clinical isolates from bloodstream infections in China.Methods:The clinical bacterial strains isolated from blood culture were collected during January 2020 to December 2020 in member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS). Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute(CLSI, USA). WHONET 5.6 was used to analyze data.Results:During the study period, 10 043 bacterial strains were collected from 54 hospitals, of which 2 664 (26.5%) were Gram-positive bacteria and 7 379 (73.5%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (38.6%), Klebsiella pneumoniae (18.4%), Staphylococcus aureus (9.9%), coagulase-negative Staphylococci (7.5%), Pseudomonas aeruginosa (3.9%), Enterococcus faecium (3.3%), Enterobacter cloacae (2.8%), Enterococcus faecalis (2.6%), Acinetobacter baumannii (2.4%) and Klebsiella spp (1.8%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 27.6% and 74.4%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci were detected. More than 95% of Staphylococcus aureus were sensitive to rifampicin and SMZco. No vancomycin-resistant Enterococci strains were detected. Extended spectrum β-lactamase (ESBL) producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 48.4%, 23.6% and 36.1%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.3% and 16.1%, respectively; 9.6% of carbapenem-resistant Klebsiella pneumoniae strains were resistant to ceftazidime/avibactam combination. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii. The prevalence rate of carbapenem-resistance of Pseudomonas aeruginosa was 23.2%. Conclusions:The surveillance results in 2020 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while Escherichia coli was the most common pathogen, and ESBL-producing strains declined while carbapenem-resistant Klebsiella pneumoniae kept on high level. The proportion and the prevalence of carbapenem-resistant Pseudomonas aeruginosa were on the rise slowly. On the other side, the MRSA incidence got lower in China, while the overall prevalence of vancomycin-resistant Enterococci was low.

Desenvolvimento e validação de um aplicativo móvel para identificação de bactérias Gram-positivas e Gram-negativas / Development and validation of a mobile application to identify Gram-positive and Gram-negative bacteria

Objetivo: A internet e os smartphones estão fortemente presentes no cotidiano mundial. Além de proporcionarem comunicação e lazer, os smartphones, por meio de aplicativos, são portas de entrada para as tecnologias da informação e comunicação, recursos utilizados por docentes e discentes como metodologia científica de ensino-aprendizado. Além disso, atuam como ferramenta de apoio para profissionais. As evoluções científicas também abrangem a microbiologia clínica, onde é possível observar a inclusão de recursos tecnológicos com o objetivo de minimizar o tempo de análise e assegurar a qualidade dos resultados; entretanto, a automatização ainda é uma realidade distante em muitos laboratórios do Brasil, portanto, o objetivo desta pesquisa foi desenvolver e validar a funcionalidade de um aplicativo como ferramenta de apoio para discentes e profissionais de microbiologia clínica. Métodos: Pesquisa metodológica, aplicada e de produção tecnológica, realizada de abril a outubro de 2019. Foi escolhida a metodologia de Galvis-Panqueva, que compõe as etapas de construção e validação. Ao final das etapas que compõem a validação, 16 discentes da Ulbra Canoas e oito profissionais de microbiologia clínica avaliaram o aplicativo quanto às percepções como usuários. Após esta avaliação, obteve-se o Índice de Validade de Conteúdo. Resultados: O Índice de Validade de Conteúdo entre os profissionais foi de 0,97 e entre os discentes foi de 0,94, valores aceitáveis para validação. Conclusão: Os resultados atingiram o objetivo proposto e corrobora com demais pesquisas da mesma linha metodológica. O aplicativo atendeu aos critérios de desenvolvimento e validação e mostrou-se uma boa ferramenta de apoio para discentes e profissionais de microbiologia clínica.

Objective: The internet and smartphones are strongly present in the daily world. In addition to providing communication and leisure, smartphones, through applications, are the gateway to Information and Communication Technologies, a resource used by teachers and students as a scientific teaching-learning methodology. In addition, they act as a support tool for professionals. Scientific developments also include clinical microbiology, where it is possible to observe the inclusion of technological resources in order to minimize the analysis time and ensure the quality of the results. However, automation is still a distant reality in many laboratories in Brazil, therefore, the objective of this research was to develop and validate the functionality of an application as a support tool for students and professionals in clinical microbiology. Methods: Methodological, applied and technological production research, carried out from April to October 2019. The GalvisPanqueva methodology was chosen, which comprises the stages of construction and validation. At the end of the steps that make up the validation, 16 students from the Ulbra Canoas and eight professionals of clinical microbiology evaluated the application regarding their perceptions as users. Afterwards, the Content Validity Index was obtained. Results: The Content Validity Index among professiona was 0,97 and among students it was 0,94, acceptable values for validation. Conclusion: The results achieved the proposed objective and corroborates with other researches of the same methodological line. The application met the development and validation criteria and proved to be a good support tool for students and professionals in clinical microbiology.

Antibacterial Activity of Mouthwash Incorporated with Silica Nanoparticles against S. aureus, S. mutans, E. faecalis: An in-vitro Study

Silica based nanoparticles are used in various fields of medical sciences to diagnose, control disease, for genetic disorders, owing to their size, surface area, biocompatibility and low toxicity. In dentistry, silica nanoparticles have been used as dental filler, teeth whitening agent but limited evidence is there regarding antimicrobial activity against oral pathogens. Therefore, the current study was conducted to assess the anti-bacterial activity of mouthwash incorporated with silica nanoparticles against oral pathogens. Tetraethoxysilane, ammonium hydroxide, absolute ethanol were used and centrifuged to obtain the silica nanoparticle pellet. XRD analysis was done to confirm the characterization of the thus obtained silica nanoparticle. The mouthwash was prepared with the synthesized silica nanoparticle as the main constituent. Agar well diffusion method was used to assess the antimicrobial activity against S. mutans, S. aureus and E. faecalis. The XRD analysis confirmed the amorphous nature of the synthesized silica nanoparticles.The zone of inhibition was found to increase as the concentrations increased mainly for S. aureus and E. faecalis. The synthesized nanoparticles incorporated mouthwash showed good potential as antimicrobial agents against strains of gram positive bacteria. Further animal studies/in vivo research should be conducted to validate the above findings

Potencial antimicrobiano e caracterização fitoquímica de extratos da casca do caule de Drimys brasiliensis Miers (Winteraceae) / Antimicrobial potential and phytochemical investigation of stem bark extracts from Drimys brasiliensis Miers (Winteraceae)

Introdução: na área da saúde, a resistência aos antimicrobianos tem se constituído um grave problema, fazendo com que a busca por alternativas farmacológicas assuma grande importância. Produtos de origem natural, como extratos de plantas, têm sido pesquisados para uso potencial no tratamento antibacteriano. Drimys brasiliensis Miers (Winteraceae) é uma árvore nativa do Brasil que tem sido utilizada como medicinal. Objetivo: investigar o perfil fitoquímico e a atividade antimicrobiana de amostras obtidas a partir de extratos da casca do caule de Drimys brasiliensis. Metodologia: frações de características químicas variadas foram obtidas a partir de extratos da casca do caule da planta. Realizou-se o screening fitoquímico destas frações através de reações gerais de caracterização e cromatografia em camada delgada. As amostras foram testadas por difusão em ágar e por microdiluição contra bactérias Grampositivas e Gram-negativas e contra uma levedura. Resultados: o perfil fitoquímico mostrou diferenças entre as frações analisadas. Alcaloides foram detectados nas frações mais apolares. Taninos e flavonoides estavam presentes nas amostras mais polares e obtidas sem o uso de calor. As amostras com maior atividade antimicrobiana foram as obtidas com os solventes hexano e diclorometano, de características mais apolares. Destaca-se a atividade contra Bacillus cereus, Staphylococcus epidermidis, Staphylococcus aureus resistente à meticilina e Candida albicans. Conclusão: extratos da casca do caule de Drimys brasiliensis apresentam potencial ntimicrobiano, com destaque para as frações mais apolares contra bactérias gram positivas.

Introduction: in the health field, antimicrobial resistance has been a serious issue, making the search for pharmacological alternatives very important. Natural products, such as plant extracts, have been researched for potential use in antibacterial treatment. Drimys brasiliensis Miers (Winteraceae) is a tree native to Brazil that has been medicinally used. Objective: to investigate the phytochemical profile and antimicrobial activity of samples obtained from Drimys brasiliensis stem bark extracts. Methodology: fractions of different chemical characteristics were obtained from extracts of the stem bark. Phytochemical screening of these fractions was performed by general reactions and thin layer chromatography. Samples were tested by agar diffusion and microdilution against Gram-positive and Gram-negative bacteria and yeast. Results: the phytochemical profile showed differences between the analyzed fractions. Alkaloids were detected in the most nonpolar fractions. Tannins and flavonoids were present in the most polar samples and obtained without the use of heat. The samples with the highest antimicrobial activity were those obtained with hexane and dichloromethane solvents, which present the most nonpolar characteristics. We highlight the activity against Bacillus cereus, Staphylococcus epidermidis, Methicillin resistant Staphylococcus aureus and Candida albicans. Conclusion: Drimys brasiliensis stem bark extracts have antimicrobial potential, especially the most nonpolar fractions against gram positive bacteria.

Neonatal Sepsis is Still a Major Problem in Tertiary Care Hospitals.

In a developing country like India, one of the most important health hazards is neonatal sepsis. The ever full SNCUs of the hospitals are living proof of this. The neonates both early and late are extremely vulnerable to all organisms, both in the community and much more so in the hospital. Neonatal sepsis contributes to infant mortality rate in a very significant way. Nosocomial neonatal sepsis is much more dangerous and contributes to morbidity and mortality in a very big way.METHODSIn this study, neonatal sepsis was assessed by culture of blood, pus from infected umbilical stump, and CSF sample received from SNCU. The isolated organisms were identified phenotypically following our laboratory protocol. Antibiotic sensitivity testing was done by Kirby-Bauer method, following CLSI guidelines.RESULTSIt was found that 48% of the total samples received from SNCU were growth positive. Klebsiella pneumoniae was isolated in maximum number of cases, 42.85% followed by Staphylococcus aureus 18.53%. Antibiotic sensitivity test by Kirby- Bauer method showed that all Gram-positive cocci were sensitive to vancomycin. There was only one linezolid resistant Staphylococcus aureus. Among the Gram-negative bacilli 100% isolates were sensitive to carbapenems. Acinetobacter baumannii and Pseudomonas aeruginosa isolates were multidrug resistant.CONCLUSIONSSNCU admitted babies are extremely vulnerable to septicaemia. The ever-changing drug resistant patterns of the infecting organisms is a perineal problem. Thus, infection control measures are to be strictly enforced in this setting.