Evaluation of Pathogens Causing Urinary Tract Infection and Their Sensitivity Pattern

Background: UTI constitute a major public health problem in India accounting 2nd most common infection next to respiratory tract infection. They are responsible for increasing treatment cost and significant morbidity.Aim:-To determine the incidence of UTI, evaluation of pathogens responsible and their antimicrobial susceptibility pattern in the population.Methods:Urine samples were collected from 300 patients attending the OPD Patna medical college, Patna during the period of 18 months (January 2017 to June 2018) Antimicrobial sensitivity testing was done for the bacterial isolates present in the sample by Kirby- Bauer disc diffusion method. Only those samples were taken into consideration which develops count equal to or greater than 1*105CFU/ml as indicated by Kass.Results:Out of 300 samples collected 146 (48.66%)) yielded bacterial growth. Out of 146 culture isolates E.Coli was the most common pathogen followed by klebsiella, CoNS and staphylococcus. Antibiotic sensitivity was performed on all the isolates. It was observed that highest sensitivity was 49.31% to amikacin, gentamycin (45.89%), nitrofurantoin (38.35%) meropenem (27.39%).Conclusions:It was observed that high grade of resistance to ampicillin, cotrimoxazole, ciprofloxacin, cefuroxime, chloramphenicol, cefotaxime, cefazolin, amoxicillin + clavulanic acid and gentamycin is present as a result of misuse or improper use of antibiotic in the community. Hence urine culture is necessary for the diagnostic screening of UTI before the treatment.

Prevalence and effect of intramammary infection due to coagulase-negative staphylococcal (CNS) species in somatic cell counts in milk from Holstein dairy cows in Boyaca, Colombia / Prevalencia y efecto de la infección intramamaria debida a especies de estafilococos coagulasa negativo (ECN) en el conteo de células somáticas en leche de vacas Holstein en Boyacá, Colombia

ABSTRACT Mastitis is one of the most important illnesses in specialized dairy herds worldwide due to the effects on production and animal health. The types caused by CNS has a special importance in a production where the main pathogens are controlled. The objective of the present work is to determine the prevalence of CNS in a dairy herd in Boyaca and also quantify the effects of every species of CNS in SCC. 40 cows were selected and sampled during 6 months, CMT was performed, and results from 1 to trace were sampled. The routine bacteriological test was also performed for CNS identification, and the isolating of CNS was performed through rpoB gene identification and through the type of strain using the pulse gel electrophoresis procedure. Out of 960 samples, 619 were positive for CNS growth. The most prevalent species were Staphylococcus epidermidis, S. chromogenes, S. sciuri, S. simulaans, S. haemolyticus and S. capitis. The results that were found here are similar to the results observed in different parts of the world, which confirms that they are pathogens that must be constantly evaluated because they can go unnoticed in routine controls, especially in those farms where major pathogens are not a serious problem. The results determined in this study demonstrate that CNS generates a slight increase in somatic cells.

RESUMEN La mastitis es una de las enfermedades más importantes en los rebaños lecheros especializados alrededor de todo el mundo debido a los efectos sobre la producción y la salud animal. Los tipos ocasionados por estafilococos coagualasa negativo (ECN) tienen una importancia especial en una producción en la que los principales patógenos están controlados. El objetivo del presente trabajo es determinar la prevalência del ECN en un hato lechero en Boyacá y cuantificar los efectos de cada especie de ECN en el conteo de células somáticas (CCS). Se seleccionaron 40 vacas y se tomaron muestras durante 6 meses, se realizó california mastitis test (CMT) y se tomaron muestras de los resultados desde 1 hasta donde hubo trazas. También se realizó la prueba bacteriológica de rutina para la identificación del ECN y el aislamiento del ECN se realizó mediante la identificación del gen rpoB y del tipo de cepa, usando el procedimiento de electroforesis en gel de pulso. De 960 muestras, 619 fueron positivas para el crecimiento del ECN. Las especies más prevalentes fueron Staphylococcus epidermidis, S. chromogenes, S. sciuri, S. simulans, S. haemolyticus y S. capitis. Los resultados encontrados aquí son similares a resultados en diferentes partes del mundo, lo que confirma que son patógenos que deben ser evaluados constantemente porque pueden pasar desapercibidos en los controles de rutina, especialmente en aquellas fincas donde los patógenos mayores no son un problema grave. Los resultados determinados en este estudio demuestran que el SNC genera un ligero aumento de células somáticas.

Dosificación empírica de vancomicina en neonatos: relación entre recomendación de dosis iniciales y relación área bajo la curva en 24 h/concentración inhibitoria mínima / Empiric vancomycin dosing in neonates: relationship between initial dose and 24 h area under the curve/minimum inhibitory concentration ratio

Resumen Introducción: Vancomicina es un antimicrobiano ampliamente utilizado para infecciones por Staphylococcus coagulasa negativa en neonatos; sin embargo, no existe claridad sobre la dosis empírica que asegure su eficacia terapéutica. Objetivo: Evaluar la relación entre las dosis iniciales de vancomicina utilizadas en una Unidad de Cuidado Intensivo Neonatal (UCIN) con la eventualidad de alcanzar el objetivo terapéutico de área bajo la curva sobre concentración inhibitoria mínima (ABC/CIM) mayor a 400 µg/h/mL. Materiales y Método: Estudio descriptivo y retrospectivo, realizado entre febrero 2016 y marzo 2018. Se incluyeron neonatos en tratamiento con vancomicina por sospecha/confirmación de infección por cocáceas grampositivas y medición de concentraciones plasmáticas de vancomicina al inicio del tratamiento. La probabilidad de alcanzar el objetivo terapéutico se evaluó mediante re-muestreo de valores de ABC y CIM. Resultados: Se incluyeron 38 pacientes con 49 concentraciones plasmáticas de vancomicina. Los aislados microbiológicos se confirmaron en 94,7% de los pacientes (n = 36). Los valores de ABC/CIM en dos grupos (según niveles valle de vancomicina < 10 µg/mL y ≥ 10 µg/mL), fueron de una mediana de 327 (IQ 25-75 = 174-395) y 494 (IQ 25-75 = 318-631), respectivamente (p = 0,035). Las dosis empíricas utilizadas logran logran un objetivo terapéutico (ABC/CIM > 400) de sólo 47,7% considerando CIMs en nuestra institución. Conclusiones: Teniendo en cuenta las sensibilidades institucionales, no es posible asegurar alcanzar ABC/CIM > 400 µg/h/mL. Se debe seguir investigando para replantear las actuales estrategias de dosificación y así determinar la más apropiada para neonatos.

Abstract Background: Vancomycin is used for treating coagulase-negative staphylococcus infections in neonates. However, concerns about the appropriate empirical dosing required for optimal efficacy, still remain. Aim: To assess the relationship between the initial doses of vancomycin used in a Neonatal Intensive Care Unit (NICU) with the possibility of achieving therapeutic target of AUC024h/MIC > 400 µg/h/mL. Methods: Retrospective and descriptive study carried out between February 2016 and March 2018. All neonates treated with vancomycin for suspected/proven Gram-positive infection and with at least one trough serum concentration level were included. Probability of target attainment (PTA) was evaluated through resampling of AUC and MIC values. Results: Final dataset included 38 patients and 49 trough vancomycin levels; 94.7% of these cases (n = 36) were confirmed Gram-positive infections. The median AUC/MIC values for the trough values vancomycin < 10 µg/mL group and for the ≥ 10 µg/mL group were 327 (IQR 174-395) and 494 (IQR 318-631) respectively (p = 0.035). Current empirical dosing strategy has a 47.7% PTA (AUC/MIC > 400) when taking institutional MICs into account. Conclusions: It is not possible to assure achieving a AUC/MIC > 400 µg/h/mL when considering institutional sensibilities. Current empiric dosing strategies should be reconsidered and further investigation needs to be done to help determine the appropriate empirical dosing required for optimal efficacy in neonates.

The challenges of neonatal sepsis management / Os desafios no manejo da sepse neonatal

Abstract Objectives To present current evidence on the etiology, risk factors, diagnosis, and management of early and late neonatal sepsis. Source of data Non-systematic review of the Medline (PubMed), Scopus, Web of Science, Cochrane, and Google Scholar databases regarding the following terms: neonatal sepsis, early neonatal sepsis, late neonatal sepsis, empirical antibiotic therapy, sepsis calculator, vancomycin, newborn, preterm newborn. Data synthesis Neonatal sepsis is a frequent cause of neonatal morbidity and mortality. Its diagnosis is difficult. Continuous observation of the patient is critical to diagnostic suspicion. When neonatal sepsis is suspected, bacteriological tests should be collected. Vancomycin should not be routinely using in the empirical antibiotic regimen in late neonatal sepsis, and the main protective mechanisms against neonatal sepsis are handwashing and the use of breast milk. Conclusions Newborns constitute a group that is more vulnerable to sepsis. Knowledge of risk factors and etiological agents allows a better approach to the newborn with sepsis.

Resumo Objetivos Apresentar evidências atuais na etiologia, fatores de risco, diagnóstico e manejo da sepse neonatal precoce e tardia. Fontes de dados Revisão não sistemática feita nas bases de dados Medline (PubMed), Scopus, Web of Science, Cochrane, Google Scholar sobre os temas sepse neonatal, sepse neonatal precoce, sepse neonatal tardia, antibioticoterapia empírica, sepsis calculator, vancomicina, recém-nascido, recém-nascido pré-termo. Síntese de dados A sepse neonatal é uma causa frequente de morbimortalidade neonatal. O seu diagnóstico é difícil. A observação contínua do paciente é fundamental para uma suspeição diagnóstica. Ao se suspeitar de sepse neonatal devem-se coletar exames bacteriológicos. Não usar, rotineiramente, vancomicina no esquema empírico de antibiótico na sepse neonatal tardia. Os principais mecanismos protetores da sepse neonatal são a lavagem de mãos e o uso do leite materno. Conclusões Os recém-nascidos constituem um grupo mais vulnerável à sepse. O conhecimento dos fatores de risco e dos agentes etiológicos permite uma melhor abordagem do recém-nascido séptico.

Identification and characterization of methicillin-resistant Staphylococcus spp. isolated from surfaces near patients in an intensive care unit of a hospital in southeastern Brazil

Abstract INTRODUCTION: Contaminated hospital environments contribute to the transmission of microorganisms associated with healthcare. Contaminated surfaces handled by patients or healthcare professionals are a source of microorganism transmission by hand. Methicillin-resistant Staphylococcus bacteria are among the main agents responsible for increasing healthcare-associated infections in Brazil and worldwide. METHODS: The objective of this study was to screen and characterize methicillin-resistant Staphylococcus spp. on surfaces near patients in an intensive care unit. Microbiological samples, collected from ten beds in an intensive care unit with five sampling sites, were inoculated into a methicillin-resistant Staphylococcus aureus chromogenic medium. MALDI-TOF and PCR analyses were used to identify the bacteria. Antimicrobial susceptibility was determined using the disk diffusion test. The presence of the mecA gene was investigated using PCR. RESULTS: We observed that 44 out of the 50 sampling sites presented grown isolates in the methicillin-resistant Staphylococcus aureus medium. The incidence of isolated microorganisms on the right side rail, left side rail, tables, infusion pump keypad, and cardiac monitor were 18.8 %, 36.7 %, 10.9 %, 2.4 %, and 31 %, respectively. The 42 isolates included in this study were identified as coagulase-negative Staphylococcus. All of these microorganisms were multidrug-resistant and mecA gene-positive. CONCLUSIONS: This study identified the presence of methicillin-resistant coagulase-negative Staphylococcus on the beds of an intensive care unit, providing evidence for the necessity of assertive actions to decrease the risk of healthcare-associated infections at the site.

A clinical, radiological and etiological study of neonatal pneumonia

Background: Pneumonia contributes to between 7, 50,000 and 1.2 million neonatal deaths and an unknown number of stillbirths each year worldwide1. It is estimated that 3.9 million of the 10.8 million deaths in children annually worldwide occur in the first 28 days of life.2 Neonatal pneumonia can be preventable if it is diagnosed as early as possible. Early recognition and prompt management are essential for the better outcome.Aim and objective: To determine bacterial etiology of neonatal pneumonia and to study the risk factors associated with neonatal pneumonia.Methods: A prospective, descriptive study was conducted for the duration of one year from July 2014 to June 2015 in Pragna children's Hospital, a tertiary care centre, Hyderabad, Telangana, India. A total of 100 neonates were admitted in Pragna children's Hospital with the signs and symptoms of neonatal pneumonia. A detailed history was taken including age, obstetric history of the mother, detailed birth history including resuscitation details and gestational age assessment were evaluated.Results: Out of 100 cases, 39(39%) neonates were preterm babies and 61(61%) were term. Also found history of Prolonged Rupture of Membrane (PROM) in 22% cases, maternal fever in 18%, home deliveries in 14% and foul smelling liquor in 18%. Out of 100 cases, 51 (51%) cases had positive finding in Chest X-Ray for neonatal pneumonia and 57(57%) had pneumonia with septicemia. Out of 100 cases, 9% of cases are positive for Coagulase negative staphylococcus (CONS), 5% for Klebsiella pneumonia, 2% for Pseudomonas aeroginosa and the remaining 84% of the cases had no growth for any organism.Conclusions: Major predisposing factors included PROM, foul smelling liquor, maternal fever, and home deliveries. CONS was the commonest organism isolated in blood culture.

Bacteriological Profile and Antibiotic Susceptibility Patterns in Neonatal Septicaemia in Tertiary Care Hospital

Introduction: Neonatal septicaemia has great role in morbidityand mortality among neonates. Neonatal mortality rate hasbeen reported in India as 17 per 1000 live births as per 2016-17 data. Neonatal septicaemia may be of early onset or lateonset depending of the age of the neonates. The mostcommon bacterial agents involved are Group B Streptococcus,Klebsiella pneumoniae, CoNS, Streptococcus pneumoniae,Haemophilus influenzae etc. Diagnosis is done by manymethods but the most important and absolute mode ofdiagnosis is blood culture.Aims and Objectives: The present study is done for thedetection of bacteriological profile and their antibioticsusceptibility pattern in case of neonatal septicaemia. Earlydiagnosis and specific treatment can save the lives of manyneonates who are suffering from neonatal septicaemia.Materials and Methods: The material used for the diagnosis isvenous blood of the suspected neonates. Blood culture methodis used for the diagnosis of Neonatal septicaemia. Repeatedsubculture is done on Blood agar, Nutrient agar, andMacConkey agar plates. Confirmation of organism is donethrough different biochemical tests. The antibiotic susceptibilitytesting was performed on Muller Hinton agar (MHA) by KirbyBauer disc diffusion method for bacterial isolates, as perclinical and laboratory standards institute (CLSI) guideline.Results: Total 206 cases of suspected neonatal septicaemiawere investigated in which 142 cases are found positive. Mostcommon organism isolated was Klebsiella pneumoniae(39.44%) than Staphylococcus aureus (33.8%), otherorganisms are Escherichia coli (9.86%), CoNS (8.48%),Pseudomonas (5.63%), Enterococcus (2.82%) etc. overallincidence of Gram negative organism (54.93%) was more thanGram positive organism (45.07%). As far as antibioticsensitivity pattern was concerned most of the organism were100% sensitive to imipenem, meropenem and colistin B andresistant to Ampicillin.Conclusion: Gram negative isolates were more common thanGram positive as the causative agents of neonatal sepsis. Themost common causative organism was Klebsiella pneumoniae.The other organisms isolated were Pseudomonas aeruginosa,Staphylococcus aureus, CoNS, etc. Most of the Gram negativeisolates were sensitive to Amikacin, Gentamycin, Ofloxacin andCiprofloxacin but were highly susceptible to Meropenem,Imipenem and Collistin-B. The Gram positive isolates werebetter sensitive to Amikacin, Cephalosporin, Ciprofloxacin andClindamycin but were less sensitive or resistant to Ampicillinand Erythromycin. They showed high susceptibility toTicoplanim, Linezolid, Vancomycin and Methicillin.

Clinical significance of procalcitonin in differentiation of bloodstream infections caused by coagulase-negative Staphylococcus from contamination in the Department of Hematology / 中国感染与化疗杂志

Objective To examine the value ofprocalcitonin (PCT) in differential diagnosis of bloodstream infections (BSI) caused by coagulase-negative Staphylococcus (CNS) from contamination in Department of Hematology.Methods One hundred and fifty-six patients with bloodstream or intravenous catheter-related CNS infection were included in this study.The patients were treated in Department of Hematology,the First Affiliated Hospital of Soochow University during the period from January 2013 to December 2015.The patients were divided into CNS bloodstream infection group (n=66) and blood culture contamination group (n=90).The two groups were compared in terms of sex,age,diagnosis,length of hospital stay,duration of neutropenia,neutrophil count and lymphocyte count,peak fever,C-reactive protein (CRP) and PCT.The receiver operating characteristic (ROC) curve was plotted with SPSS 21.0 software to analyze the value of PCT in differential diagnosis.Results Age,sex,clinical diagnosis,length of hospital stay,duration of neutropenia,neutrophil count and lymphocyte count did not show significant difference between bloodstream infection group and contamination group (P＞0.05),while peak fever (P＜0.001),CRP (P=0.002) and PCT (P=0.018) were significantly higher in bloodstream infection group than in contamination group.ROC analysis indicated that PCT provided optimal discrimination between these two groups at cnt-offvalue of 0.374 μg/L,with sensitivity of 54.5％ and specificity of 94.4％.The area under the curve (AUC) was 0.830±0.032 (95％ CI:0.767-0.893,P＜0.001).Conclusions PCT may be a good marker for differentiating CNS bloodstream infection from contamination with higher specificity than the commonly used marker CRP.This finding may help clinicians reduce the overuse of antibiotics.

Capacidad de formación de biopelícula y limo en Staphylococcus que causan mastitis subclínica bovina en el estado Zulia-Venezuela / Biofilm formation and slime producing ability in Staphylococci causing subclinic bovine mastitis in the Zulia state-Venezuela

Un total de 79 cepas de S. aureus y 47 cepas de Staphylococcus coagulasa negativa (SCN) aislados de muestras de leche de vaca con mastitis subclínica fueron evaluadas para establecer su propiedad para formar biopelícula como uno de los factores de virulencia más importantes. Usando el método de Rojo Congo Agar, 80% de las cepas de S. aureus fueron productores de limo, mientras que en las cepas de SCN el porcentaje fue de 32%. Por el método de microplaca, 55%, 17% y 28% de los aislamientos de S. aureus fueron fuerte, moderadas y débiles productoras de biopelícula, mientras en los SCN el porcentaje fue 43%, 17% y 40%, respectivamente. Se realizó un ensayo de Reacción en Cadena de la Polimerasa (PCR) a todos los aislamientos con la finalidad de identificar el gen A de adhesión intracelular (icaA). En las cepas de S. aureus el gen icaA estuvo presente en el 65% de los aislamientos, y en los SCN en el 11%. La mayoría de las cepas de S. aureus caracterizados en el estudio fueron formadores de biopelícula, lo cual sugiere que está tiene un importante papel en la virulencia de S. aureus aislados de infecciones intramamarias en bovinos del estado Zulia.

A total of 79 S. aureus strains and 47 coagulase negative Staphylococcus (CNS) isolates from cow milk suffering subclinical mastitis were investigated for their ability to form biofilm as one of the most important virulence factors. Using Congo Red Agar method, 80% of S. aureus strains were slime producers, while in CNS was 32%. By microtiter plate method, 55%, 17%, and 28% of S. aureus isolates were strong, moderate, and weak biofilm producers, respectively, while in CNS the percentages were 43%, 17%, and 40%, respectively. All isolates were screened by Polymerase chain reaction (PCR) for amplification of intercellular adhesion gene A (icaA). In S. aureus isolates the icaA gene was present in 65 % while in CNS was 11%. The majority of S. aureus characterized in this study formed biofilm, which suggests that biofilm formation has an important role in the virulence of S. aureus isolated from bovine intramammary infections in Zulia state.

Evaluation of BD MAX Staph SR Assay for Differentiating Between Staphylococcus aureus and Coagulase-Negative Staphylococci and Determining Methicillin Resistance Directly From Positive Blood Cultures

BACKGROUND: We evaluated the performance of the BD MAX StaphSR Assay (SR assay; BD, USA) for direct detection of Staphylococcus aureus and methicillin resistance not only in S. aureus but also in coagulase-negative Staphylococci (CNS) from positive blood cultures. METHODS: From 228 blood culture bottles, 103 S. aureus [45 methicillin-resistant S. aureus (MRSA), 55 methicillin-susceptible S. aureus (MSSA), 3 mixed infections (1 MRSA+Enterococcus faecalis, 1 MSSA+MRCNS, 1 MSSA+MSCNS)], and 125 CNS (102 MRCNS, 23 MSCNS) were identified by Vitek 2. For further analysis, we obtained the cycle threshold (Ct) values from the BD MAX system software to determine an appropriate cutoff value. For discrepancy analysis, conventional mecA/mecC PCR and oxacillin minimum inhibitory concentrations (MICs) were determined. RESULTS: Compared to Vitek 2, the SR assay identified all 103 S. aureus isolates correctly but failed to detect methicillin resistance in three MRSA isolates. All 55 MSSA isolates were correctly identified by the SR assay. In the concordant cases, the highest Ct values for nuc, mecA, and mec right-extremity junction (MREJ) were 25.6, 22, and 22.2, respectively. Therefore, we selected Ct values from 0-27 as a range of positivity, and applying this cutoff, the sensitivity/specificity of the SR assay were 100%/100% for detecting S. aureus, and 97.9%/98.1% and 99.0%/95.8% for detecting methicillin resistance in S. aureus and CNS, respectively. CONCLUSIONS: We propose a Ct cutoff value for nuc/mec assay without considering MREJ because mixed cultures of MSSA and MRCNS were very rare (0.4%) in the positive blood cultures.

Clinical significance and cut-off value of the infection of coagulase-negative staphylococcus obtained from cerebrospinal fluid specimens in neurosurgical patients / 中华检验医学杂志

Objective To study on the contribution and cut-off value of coagulase negative staphylococcus (CoNS) in laboratory tests of postoperative infection in neurosurgery and optimize the diagnostic criteria of infection.Methods It made a retrospective study of 650 cerebrospinal fluid (CSF)specimens from neurosurgical patients,who were infected CoNS in Beijing Tiantan Hospital affiliated to Capital Medical University during 2013-2015.The epidemiological data were collected and 8 routine clinical laboratory tests were performed.T test was used to compare the difference among the groups.By making receiver operating characteristic (ROC) curve,the area under the curve (AUC),cut-off value,sensitivity and specificity were obtained.Results A total of 19 756 CSF specimens were collected and 650 CoNS were isolated.The separation rate of CoNS was 3.3％ which was the most frequently isolated bacteria.The differences of cerebrospinal fluid white blood cell count (3 598.6 ± 1 884.3,678.1 ± 629.1,t =2.662,P =0.012),multinucleated cell ratio in cerebrospinal fluid(76.0 ±32.6,46.8 ±29.9,t =9.593,P =0.001),cerebrospinal fluid glucose concentration (5.9 ± 2.12,6.2 ± 1.92,t =-16.296,P =0.001) and cerebrospinal fluid glucose concentration/blood glucose concentration (0.3 ± 0.16,0.63 ± 0.31,t =-11.968,P =0.000) among groups were statistically significant.The AUCs of cerebrospinal fluid white blood cell count,cerebrospinal fluid glucose and cerebrospinal fluid glucose/blood glucose were more than 0.8,and the sensitivities of the three indicators were more than 80.0％.In addition,the specificity of cerebrospinal fluid glucose concentration/blood glucose concentration was more than 0.9.Conclusions CoNS was the main pathogenic bacteria of neurosurgical infections in a hospital.Cerebrospinal fluid white blood cell count,cerebrospinal fluid glucose and the ratio of cerebrospinal fluid glucose and blood glucose could be used for auxiliary diagnosis of CoNS infections in neurosurgical patients.

Resistencia a oxacilina, eritromicina y gentamicina en cepas de Staphylococcus coagulasa negativa aisladas de hemocultivos / Resistance to oxacillin, erythromycin and gentamycin in coagulase negative Staphylococcus strains isolated from blood cultures

La resistencia a los antimicrobianos en bacterias Gram positivas como Staphylococcus coagulasa negativa constituye una amenaza mundial emergente. El propósito de la presente investigación fue identificar los genes de resistencia a oxacilina (mecA), eritromicina (erm y msrA), y gentamicina aac(6´)/aph(2´´), en cepas de Staphylococcus coagulasa negativa aisladas de hemocultivos de pacientes atendidos en el Hospital Universitario de Maracaibo. La detección fenotípica se realizó mediante métodos automatizados. Se utilizó la reacción en cadena de la polimerasa para detectar la presencia de genes de resistencia a los antimicrobianos. Se estudiaron 34 cepas cuya distribución por especie fue: S. haemolyticus (38,23%), S. epidermidis (29,42%), S. hominis (26,47%), S. xylosus y S. capitis (5,88% cada uno). Todas las cepas fueron resistentes a oxacilina. La resistencia a gentamicina varió entre 38,46% y 100%; mientras que la resistencia a eritromicina osciló entre 77,78% y 100%. Los análisis mostraron la presencia de los genes mecA (100%), ermA (35,2%), ermC (41,17%), msrA (17,64%), y aac(6´)/aph(2´´) (61,76%). En conclusión, se encontró una alta frecuencia de genes de resistencia a estos antibióticos y la Unidad de Cuidados Intensivos fue el servicio médico donde se aisló el mayor porcentaje de cepas portadoras de estos genes.

Resistance to antimicrobials in Gram-positive bacteria such as coagulase negative Staphylococcus is an emerging global threat. The purpose of this research was to identify the genes for resistance to oxacillin (mecA), erythromycin (erm and msrA), and gentamicin aac(6´)/aph(2´´), in Staphylococcus coagulase negative strains isolated from blood cultures from patients attended at the University Hospital in Maracaibo. Phenotypic detection was performed using automated methods. Polymerase chain reaction was used for the detection of antimicrobial resistance genes. Be studied 34 strains whose distribution by species was: S. haemolyticus (38.23%), S. epidermidis (29.42%), S. hominis (26.47%), S. xylosus and S. capitis (5.88% each one). All strains were resistant to oxacillin. Gentamicin resistance varied between 38.46% and 100%; while the erythromycin resistance ranged between 77.78% and 100%. The analyses showed the presence of genes mecA (100%), ermA (35.2%), ermC (41.17%), msrA (17.64%), and aac(6´)/aph (2´´) (61,76%). In conclusion, is found a high frequency of genes for resistance to these antibiotics and the intensive care unit was the health service where the highest percentage of isolated strains carriers of these genes.

Comparison phenotypic and genotypic identification of Staphylococcus species isolated from bovine mastitis / Comparação da identificação fenotípica e genotípica de espécies do gênero Staphylococcus isoladas de mastite bovina

In addition to Staphylococcus aureus nowadays other coagulase-positive staphylococci (CoPS) and coagulase-negative staphylococci (CoNS), earlier considered of minor importance, are now accepted as relevant pathogens for humans and animals. The involvement of these microorganisms in bovine mastitis etiology and the possibility their transmission through milk to humans justify the requirement of developing reliable methods for identification of the most frequent species among them. The purpose of this study was to compare the phenotypic techniques with the genotypic method carried out by sequencing of the rpoB gene in identification of several species of the genus Staphylococcus isolated from bovine mastitis. A total of 300 staphylococci isolates of bovine mastitis cases from several Brazilian dairy herds were studied by phenotypic and genotypic techniques, respectively: 150 CoPS and 150 CoNS strains. A total of 18 CoNS different species and 4 CoPS species were identified. Among the CoNS the following species were recognized: 48 (32%) Staphylococcus warneri, 22(15%) S. epidermidis, 20(13%) S. hyicus, 10(7%) S. xylosus, 7(5%) S. haemolyticus, 6(4%) S. simulans, 6(4%) S. schleiferi subsp schleiferi, 6(4%) S. hominis, 5(3%) S. pasteuri, 4(2.7%) S. cohnii, 3(2%) S. saprophyticus subsp. saprophyticus 3(2%) S. chromogenes 3(2%) S. sciuri, 2(1%) S. saccharolyticus, 2(1%) S. lugdunensi, 1(0,7%) S. auricularis, 1(70%) S. saprophyticus subsp. bovis, 1(0.7%) S. capitis. And among the 150 CoPS were identified respectively: 105 (70%) S. aureus, 21(14%), S. hyicus, 19(13%) S. intermedius e 5(3%) S. schleiferi subsp coagulans. Considering the 150 CoNS isolates, the identifications performed by phenotypic and genotypic tests presented 96.7% of concordance, kappa coefficient of agreement = 0.933, SE (standard error) of kappa=0.021 (95% confidence interval: 0.893 to 0.974), Pearson's correlation coefficient (r) = 0.9977, (confidence interval 95%: 0.9938 a 0.9992) and in relation to 150 CPS isolates it was detected an agreement of 98.7%, kappa = 0.960, SE of kappa = 0.016, (95% confidence interval: 0.929 to 0.992) Pearson's correlation coefficient (r) = 0.9994 (95% confidence interval: 0.9681 to 1.0000). The verified agreement strength between the identification methods can be considered as excellent. These results assure that according to laboratory resources any of them will be suitable to perform the staphylococci identification.(AU)

Além de Staphylococcus aureus atualmente outros estafilococos coagulase positiva (SCP) e estafilococos coagulase-negativos (SCN), anteriormente considerados de menor relevância, são reconhecidos como importantes patógenos para humanos e animais. O envolvimento desses micro-organismos na etiologia da mastite bovina e a possibilidade da sua transmissão através do leite aos humanos justifica a utilização de métodos confiáveis para a identificação das espécies mais frequentes. O objetivo deste estudo foi comparar as técnicas fenotípicas com o método genotípico realizada por sequenciamento do gene rpoB na identificação de espécies do gênero Staphylococcus spp. isolados de mastite bovina. Um total de 300 estafilococos isolados de casos de mastite bovina em diferentes rebanhos leiteiros brasileiros foram estudados por técnicas fenotípicas e genotípicas, respectivamente: 150 linhagens de SCP e 150 linhagens de SCN. Foram identificados um total de 18 espécies de SCN e 4 espécies SCP. Entre os SCN as seguintes espécies identificadas: 48 (32%) Staphylococcus warneri, 22 (15%) S. epidermidis, 20 (13%) S. hyicus, 10 (7%) S. xylosus, 7 (5%) S. haemolyticus, 6 (4%) S. simulans, 6 (4%) S. schleiferi subsp schleiferi, 6 (4%) S. hominis, 5 (3%) S. pasteuri, 4 (2,7%) S. cohnii, 3 (2%) S. saprophyticus subsp. saprophyticus, 3 (2%) S. chromogenes, 3 (2%) S. sciuri, 2 (1%) S. saccharolyticus, 2 (1%) S. lugdunensi, 1 (0,7%) S. auricularis, 1 (70 %) S. saprophyticus subsp. bovis, 1 (0,7%) S. capitis. E entre as 150 SCP foram identificados, 105 (70%) S. aureus, 21 (14%), S. hyicus, 19 (13%) S. intermedius e 5 (3%) S. schleiferi subsp coagulans. Considerando-se os 150 SCN isolados, as identificações realizadas por testes fenotípicos e genotípicos apresentaram 96,7% de concordância, coeficiente de concordância kappa = 0,933, SE (erro padrão) de kappa = 0,021 (95% intervalo de confiança: 0,893-0,974), coeficiente de correlação de Pearson (r) = 0,9977, (intervalo de confiança de 95%: 0,9938 a 0,9992) e em relação a 150 SCP isolados foi observado uma concordância de 98,7%, kappa = 0,960, sE de kappa = 0,016, (95% de intervalo de confiança: 0,929 a 0,992) coeficiente de correlação de Pearson (r) = 0,9994 (95% intervalo de confiança: 0,9681-1,0000). A correlação entre os métodos de identificação pode ser considerada como excelente. Esses resultados demonstraram que de acordo com os recursos disponíveis no laboratório, poderia ser utilizada qualquer uma das metodologias.(AU)

Bacteremia por Staphylococcus coagulasa negativo con concentración inhibitoria mínima para vancomicina ≥ 2 / Coagulase-negative Staphylococcus bacteremia with Vancomycin minimum inhibitory concentrations ≥ 2

Introducción: La bacteremia por Staphylococcus coagulasa negativo (SCN) es una infección que actualmente genera significativa morbimortalidad dado el tipo de pacientes a los que afecta y el cambio en el perfil de susceptibilidad a los antibióticos. Objetivo: Describir características de los pacientes con aislamientos de SCN en sangre con CIM para vancomicina ≥2. Metodología: Estudio observacional descriptivo en pacientes hospitalizados ≥ 15 años. Resultados: De 130 aislamientos, 38 (29,23%) tenían CIM para vancomicina ≥ 2. La mediana de edad fue de 54 años y la razón hombre:mujer, de 1,37:1. Las especies más frecuentes fueron: S. epidermidis (71,1%), S. haemolyticus (13,2%) y S. hominis (7,9%). El 44,7% tenían antecedentes de inmunosupresión, siendo las más importantes: neoplasias (28,9%), enfermedad reumatológica (5,2%) y VIH (2,6%). El 81,5% tenían accesos vasculares, el 97,3% antecedente de hospitalización previa y el 60,5% habían requerido manejo en la UCI. El 81,4% tuvieron exposición previa a antibióticos, y los más utilizados fueron: betalactámicos (78,9%) y vancomicina (50%). En el 2,6% se documentó endocarditis infecciosa. De los aislamientos de SCN con CIM para vancomicina ≥2 µg/ml, el 26,3% fueron sensibles a meticilina. Los principales tratamientos recibidos fueron: daptomicina (31,5%), vancomicina (21%), linezolid (15,7%) y betalactámicos (10,5%). Se utilizó terapia combinada en el 10,5%. La mortalidad general fue del 15,8%, y la mortalidad atribuible, del 33,3%. Conclusión: Un porcentaje considerable de aislamientos tenían heterorresistencia para vancomicina. La bacteremia estuvo asociada con accesos vasculares, hospitalizaciones previas, tratamientos en cuidado intensivo y exposición previa a antibióticos. La inmunosupresión es la comorbilidad más importante, y la mortalidad es significativa.

Introduction: Currently, coagulase-negative Staphylococcus (CNS) bacteremia is an infection that leads to significant morbidity and mortality given the type of patients affected and the recent changes in antimicrobial susceptibility. Objective: To describe the characteristics of patients with CNS blood isolates with vancomycin MIC ≥ 2. Methodology: Descriptive observational study on hospitalised patients ≥ 2 15 years of age. Results: Of 130 isolates, 38 (29,23%) contained vancomycin MIC ≥ 2. The median age was 54 years and the male:female ratio was 1.37:1. The most frequent species were S. epidermidis (71.1%), S. haemolyticus (13.2%) and S. hominis (7.9%). Some 44.7% of patients had a history of immunosuppression, including: neoplasms (28.9%), rheumatologic disease (5.2%) and HIV (2.6%). Some 81,5% had vascular access; 97.3% had previous hospitalisations and 60.5% had required intensive care. A total of 81.4% of the patients had prior exposure to antibiotics and the most commonly used were beta-lactams (78.9%) and vancomycin (50%). Infective endocarditis was documented in 2.6%. Of the CNS isolates with vancomycin MIC ≥ 2, 26.3% were sensitive to methicillin. The main treatments received were: daptomycin (31.5%), vancomycin (21%), linezolid (15.7%) and betalactams (10.5%). Combined therapy was performed in 10.5%. The overall mortality was 15.8% and attributable mortality was 33.3%. Conclusion: A significant proportion of isolates were hetero-resistant to vancomycin. The bacteremia was associated with vascular access, previous hospitalisations, intensive care treatments and prior antibiotic exposure. Immunosuppression is the most important comorbidity and mortality is significant.

Blood Culture and Sensitivity Profile Study in a Tertiary Medical Hospital in Kolkata, West Bengal: 7 Years’ Experience.

Aims and objectives: To identify the prevalence of bacteremia and the spectrum of antimicrobial sensitivity in our community, because it will guide the clinician to institute proper antimicrobial therapy. Background: Bacteremia originates from either intravascular sites or extraVascular sites. In case of bloodstream infection, either Gram-positive or Gram-negative bacteria are responsible. Of these bacterial isolates, Gram-negative bacteria are responsible for higher mortality and morbidity. Since 20 to 30 years, coagulase-negative Staphylococci are responsible for most infection. Materials and methods: In this retrospective study, blood samples were collected aseptically from 11,581 patients and were injected into the bottles containing bile-broth and brainheart infusion broth and allowed to be incubated at 37°. Then subculture was done on blood agar, chocolate agar, as well as MacConkey agar media and was kept for 7 days or till the appearance of growth of the organism. After identification of isolates, Kirby Bauer disk diffusion test on Mueller-Hinton agar II was performed to detect antimicrobial sensitivity. Results: Our study documented 8.58% positive cultures in the last 7 years. Gram-negative bacterial isolates were significantly higher than Gram-positive isolates (64.19% vs 34.80%, p = 0.00). Lowest number of positivity was seen in Morganella (0.40%) followed by Proteus (0.50%) and Enterococcus faecium (0.90%) in ascending order. Males were significantly more culture positive than females (549/994 vs 445/994, p = 0.00). Most common bacterial isolates were (coagulase negative Staphylococci) CoNS (239, 24.04%) followed by Klebsiella including ESBL (extended spectrum beta-lactamase), carbapenamase producer (234, 23.74%) and Escherichia coli (110, 11.06%). E. coli was >75% sensitive to imipenem group, polymyxin B (98.18%), colistin (96.36%), and amikacin (80.9%). Coagulase negativeStaphylococci showed more than 60% sensitivity to levofloxacin (76.98%), amikacin (82.84%), tigecycline (87.44%), vancomycin (94.45%), teicoplanin (91.63%), linezolid (91.21%), gentamicin (76.56%), netilmicin (74.47%), and tetracycline (75.31%). Klebsiella (non-ESBL and carbapenemase producer) was highly sensitive to polymyxin B (93.06%), colistin (91.90%), meropenem (65.31%), and imipenem (94.73%). Extended spectrum beta-lactamase-producing Klebsiella showed increased sensitivity to meropenem (89.47%), imipenem (94.73%), ertapenem (81.57%), polymyxin B, and colistin (97.36% each). Conclusion: Positive cultures were 8.58% in the last 7 years. Gram negative bacterial isolates were significantly higher. Males were more culture positive. Most common bacterial isolates were CoNS followed by Klebsiella species and E. coli. Gram-negative bacterial isolates were highly sensitive to piperacillin, cefoperazone, imipenem, meropenem, aminoglycoside group of antibiotics, tigecycline, polymyxin B and colistin. Gram-positive bacterial isolates were sensitive to piperacillin, cefoparazone, vancomycin, teicoplanin, linezolid and clindamycin. Salmonella typhi were sensitive to ampicillin, cefoparazone, cefepime, azithromycin, chloramphenicol, and fluoroquinolones. Acinetobacter showed > 50% sensitivity to cefepime and Pseudomonas showed > 50% sensitivity to cefotaxime and levofloxacin. So to prevent resistance of bacterial isolates, a proper antibiotic guideline should be maintained.

Effect of improving disinfection methods for skin and bottle caps on the detection rate of coagulase negative staphylococcus from blood culture / 中国感染控制杂志

Objective To compare different disinfection methods for skin and bottle caps on the detection rate of coagulase negative staphylococcus(CNS)from blood culture,and provide basis for improving collection process and accuracy of blood culture.Methods Blood specimens from the neonatal department of a hospital between June 2012 and August 2014 were collected,blood specimens cultured between June 2012 and June 2013 were as control group (routine disinfection during blood collection process),and blood specimens cultured between August 2013 and Au-gust 2014 were as intervention group (improved disinfection method for skin and bottle caps),detection rates of CNS between two groups were compared.Results In control group,41 isolates of pathogens were isolated from 543 blood culture specimens,positive rate was 7.55%;in intervention group,21 isolates of pathogens were isolated from 853 blood culture specimens,positive rate was 2.46%.The detection rate of CNS in control group was 4.97%(n=27),12 (2.21 %)of which were methicillin-resistant coagulase-negative staphylococcus (MRCNS);the detec-tion rate of CNS in intervention group was 0.82%(n=7),6 (0.70%)of which were MRCNS.Difference in detec-tion rates of CNS and MRCNS between two groups were both statistically significant(χ2 =24.07,5.92,both P <0.05).Conclusion Improving disinfection methods for skin and caps of blood culture bottles during blood collection can decrease the detection rate of CNS.

Tiempo de crecimiento bacteriano en hemocultivos en neonatos / Time bacterial growth in blood cultures in neonates Abstract

Introducción: La sepsis es causa importante de morbimortalidad neonatal. Objetivos: Detectar el tiempo en que la curva de crecimiento bacteriano es evidenciada en la muestra de sangre inoculada en los hemocultivos y comparar estos tiempos de crecimiento bacteriano entre bacterias gramnegativas y grampositivas, entre los tipos de sepsis neonatal y determinar las bacterias más frecuentemente aisladas entre neonatos prematuros y de término. Pacientes y método: Estudio descriptivo de recién nacidos en riesgo de sepsis o con sospecha de sepsis por manifestaciones clínicas o de laboratorio, en que se evaluaron 114 hemocultivos positivos entre 1.932 hemocultivos tomados entre mayo de 2010 y mayo de 2014. Los datos se analizaron con Stata® 11.0. Resultados: El 5,9% de los hemocultivos tuvieron crecimiento bacteriano. La mediana y rango intercuartílico de tiempos de crecimiento bacteriano para gramnegativos fue 11 h (10-13 h), para grampositivos diferentes a Staphylococcus coagulasa negativo (SCoN) 12 h (12-18 h) y para SCoN 42h (36-44h). El 95,8% de las bacterias grampositivas y el 96% de las gramnegativas tuvieron tiempos de crecimiento bacteriano ≤ 24 h de incubación, mientras que en los SCoN el 100% de los hemocultivos fue positivo en ≤ 62 h de incubación. Conclusión: El 100% de sepsis por bacterias gramnegativas, grampositivas no SCoN y 90% de las ocasionadas por SCoN, son identificadas en los hemocultivos en las primeras 48 h, por lo cual podemos concluir que para descartar una sepsis, un período de incubación en hemocultivos de 48 h es suficiente.

Introduction: Sepsis is a major cause of neonatal morbidity and mortality. Objectives: To detect the time when the bacterial growth curve is evidenced in the blood sample inoculated blood cultures and comparing the times of bacterial growth between Gram negative and Gram positive bacteria, among the types of neonatal sepsis and identifying microorganisms more often isolated from preterm and term. Patients and method: A descriptive study. 114 positive blood cultures from 1,932 blood cultures taken from 01-May-2010 and 31-May-2014 were evaluated. Data were analyzed with Stata® 11.0. Results: 5.9% of blood cultures had bacterial growth. The median and interquartile range of Gram negative times of bacterial growth was 11 h (10-13 h), for Gram positive coagulase-negative Staphylococcus different (CoNS) 12h (12-18h) and CoNS 42h (36-44h). 95.8% of Gram positive and 96% of Gram negative, were the times of bacterial growth ≤ 24 h incubation, whereas the 100% CoNS was positive ≤ 62 h of incubation. Conclusion: 100% of sepsis by Gram negative and Gram positive no CoNS and 90% of those caused by CoNS are identified in blood cultures in 48 h, so we can conclude that to rule out sepsis, an incubation period of 48 h in blood cultures is sufficient.

Beta-lactamase detection in Staphylococcus aureus and coagulase-negative Staphylococcus isolated from bovine mastitis / Detecção de beta-lactamase em Staphylococcus aureus e Staphylococcus coagulase negativa isolados de mastite bovina

The objectives of the study were to evaluate the presence/production of beta-lactamases by both phenotypic and genotypic methods, verify whether results are dependent of bacteria type (Staphylococcus aureus versus coagulase-negative Staphylococcus - CNS) and verify the agreement between tests. A total of 200 bacteria samples from 21 different herds were enrolled, being 100 CNS and 100 S. aureus. Beta-lactamase presence/detection was performed by different tests (PCR, clover leaf test - CLT, Nitrocefin disk, and in vitro resistance to penicillin). Results of all tests were not dependent of bacteria type (CNS or S. aureus). Several S. aureus beta-lactamase producing isolates were from the same herd. Phenotypic tests excluding in vitro resistance to penicillin showed a strong association measured by the kappa coefficient for both bacteria species. Nitrocefin and CLT are more reliable tests for detecting beta-lactamase production in staphylococci.

Os objetivos do presente estudo foram avaliar a presença/produção de beta-lactamases por ambos os métodos fenotípicos e genotípicos, verificar se os resultados são dependentes do tipo de bactéria (Staphylococcus aureus contra Staphylococcus coagulase negativa - CNS) e verificar a concordância entre os testes. Um total de 200 amostras bactérianas oriundas de 21 rebanhos distintos foram incluídos, sendo 100 CNS e 100 S. aureus. A presença/detecção de beta-lactamase foi realizada por diferentes testes (PCR, teste trevo (clover leaf test) - CLT, disco Nitrocefin e resistência in vitro à penicilina). Os resultados de todos os testes não foram dependentes do tipo de bactérias (CNS ou S. aureus). Vários isolados de S. aureus produtores de beta-lactamase eram de um mesmo rebanho. Testes fenotípicos excluindo resistência in vitro à penicilina mostraram uma forte associação medida pelo coeficiente kappa para ambas as espécies de bactérias. Nitrocefina e CLT são testes mais confiáveis para detectar a produção de beta-lactamase em estafilococos.

High resistance to Azithromycin- A cause of concern.

Macrolide antibiotics are well established class of antimicrobial agents. Azithromycin due to better tolerance and once a daily dose is commonly prescribed by clinician today. The aim of our study was to analyze the resistance to erythromycin in all gram positive bacteria isolated in department of microbiology Dr. RPGMC Tanda. A result of antibiotic susceptibility testing done by Kir By bauer disc diffusion method were analysed, Of the totral gram positive isolates 54 % were resistant to Azithromycin with maximum resistance seen with Enterococcus species (75 %) . It is recommended that an antibiotic policy should be made and microbiological surveillance cotinued so as to decrease the selective pressure on microorganisms.

Homologx analxsis on Staphylococcus isolated from infectious wound-re-lated environmental specimens / 中国感染控制杂志

Objective To monitor Staphylococcus infection in a hospital,and trace the source of Staphylococcus isolated from infectious wound-related hospital environment by molecular analysis. Methods By combination of fluorescence quanti-tative polymerase chain reaction (FQ-PCR)and culture method,environmental specimens related to 5 patients with wound infection were taken and performed multilocus sequence and MecA gene typing analysis. Results A total of 71 environmen-tal specimens were taken,Staphylococcus accounted for 36.62% (n= 26),88.46% (23/26 )of which were MecA+ methi-cillin-resistant strains. 77.78% (7/9)of Staphylococcus aureus (S. aureus)and 95.00% (19/20)of coagulase negative Staphylococcus (CNS)were methicillin-resistant strains. Multilocus sequence analysis revealed that ST239 (n= 6)was the most common sequence type in S. aureus;Staphylococcal cassette chromosome mec (SCCmec)analysis showed that the ma-jor type of S. aureus was typeⅢ,and CNS were typeⅢandⅣ. Conclusion Staphylococcus is common in healthcare-associated infection,and most Staphylococcus are multidrug-resistant,continuous monitor on drug-resistant Staph-ylococcus is necessary,and risk of Staphylococcus variant to medical institutes need to be paid attention.