In vitro susceptibility to fosfomycin in clinical and environmental extended-spectrum beta-lactamase producing and/or ciprofloxacin-non-susceptible Escherichia coli isolates

ABSTRACT Extended-spectrum beta-lactamase producing and ciprofloxacin-non-susceptible Escherichia coli are clinical and environmental issues. We evaluated the susceptibility profile of fosfomycin in non-susceptible E. coli isolated from urine and the environment. We measured the activity of fosfomycin against 319 and 36 E. coli strains from urine and environmental isolates, respectively, collected from rivers. Fosfomycin resistance profiles were investigated using the minimal inhibitory concentration (MIC), according to the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) guidelines. Antibiotic susceptibility testing revealed that 5% and 6.6% of urine samples were non-susceptible to fosfomycin according to CLSI and EUCAST guidelines, respectively. The fosfomycin MIC50/90 was 0.5/4 mg/L. Of the 36 E. coli isolates from river water, 11.1% and 13,8% were non-susceptible to fosfomycin according to CLSI and EUCAST, respectively (range ≤0.25 ≥512 mg/L). All the isolates with MIC ≥512 mg/L for fosfomycin showed the fosA3 gene. Fosfomycin resistance was more frequent in the environment than in clinical samples.

Métodos diagnósticos para tuberculose: uma revisão integrativa / Diagnostic methods for tuberculosis: an integrative review

A tuberculose é doença muito prevalente, com 5,8 milhões de casos ao ano, podendo apresentar padrão multissistêmico de acometimento, sendo mais comum a forma pulmonar. Objetivo: Revisão de literatura acerca dos métodos existentes de diagnóstico da tuberculose, focada em suas eficácias. Método: Foi realizada revisão integrativa por meio de publicações de 2016 a 2022 obtidas na base de dados PubMed e Scielo. Foram usados os descritores: Mycobacterium tuberculosis AND diagnosis. Foram obtidos 14 artigos que satisfizeram os critérios de inclusão. Resultado: Das formas de diagnóstico existem exames de imagem (Raio-X e tomografia computadorizada), baciloscopia, cultura e moleculares. Conclusão: Os métodos por imagem têm relevância quando seus achados são correlacionados com a clínica e podem auxiliar no diagnóstico. Nos métodos bacteriológicos, o sistema do GeneXpert Ultra apresenta maior custo-benefício, com valores de sensibilidade e especificidade altos - acima de 90% - superior à baciloscopia, e com menor tempo para realização em comparação com a cultura

nd may present a multisystem pattern of involvement, with the pulmonary form being the most common. Objective: Literature review on existing methods used to diagnose tuberculosis. Method: An integrative review was carried out through publications from 2016 to 2022 in the PubMed and Scielo publication database. The descriptors were used: Mycobacterium tuberculosis AND diagnosis. Fourteen articles that met the inclusion criteria were obtained. Result: Among the ways of diagnosing tuberculosis, there are imaging tests (X-ray and computed tomography), bacilloscopy, culture and molecular tests. Conclusion: Imaging methods have their findings correlated and can aid in the diagnosis. In bacteriological methods, the GeneXpert Ultra system is cost-effective, with high sensitivity and specificity values - above 90% -, superior to bacilloscopy, with a shorter time to perform compared to culture

Validation of multiplex PCR for the diagnosis of acute bacterial meningitis in culture negative cerebrospinal fluid / Validação do PCR multiplex para o diagnóstico de meningite bacteriana aguda com cultura de liquido cefalorraquidiano negativa

ABSTRACT This study evaluated the operational characteristics of the multiplex polymerase chain reaction (PCR) for cerebrospinal fluid (CSF) from patients with cellular and biochemical characteristics of acute bacterial meningitis and positive or negative CSF cultures. Methods: Multiplex PCR was performed for 36 CSF samples: culture-proven acute bacterial meningitis (n = 7), culture-negative acute bacterial meningitis (n = 17), lymphocytic meningitis (n = 8), and normal CSF (n = 4). The operational characteristics of multiplex PCR were evaluated with definite and probable bacterial meningitis, using culture positive, cytological and biochemical CSF characteristics as the gold standard. Results: Multiplex PCR for CSF was efficient in the group with CSF cellular and biochemical characteristics of acute bacterial meningitis but with a negative CSF culture. This group demonstrated high specificity, positive predictive value, and efficiency. Conclusions: Multiplex PCR for CSF can improve the speed and accuracy of acute bacterial meningitis diagnosis in a clinical setting as a complement to classical immunological and bacteriological assays in CSF. It is also useful for CSF culture-negative acute bacterial meningitis.

RESUMO Este estudo avaliou as características funcionais da reação em cadeia da polimerase (PCR) multiplex para amostras de líquido cefalorraquidiano (LCR) de pacientes com características celulares e bioquímicas de meningite bacteriana aguda e culturas de LCR positivas ou negativas. Métodos: O PCR multiplex foi realizado em 36 amostras de LCR: meningite bacteriana aguda comprovada por cultura (n = 7), meningite bacteriana aguda com cultura negativa (n = 17), meningite linfocítica (n = 8) e LCR normal (n = 4). As características funcionais do PCR multiplex foram avaliadas para meningite bacteriana definitiva e provável, utilizando cultura positiva, características citológicas e bioquímicas do LCR como padrão-ouro. Resultados: O PCR multiplex do LCR foi eficiente no grupo com características celulares e bioquímicas do LCR de meningite bacteriana, mas com cultura do LCR negativa. Este grupo demonstrou especificidade, valor preditivo positivo e eficiência altos. Conclusões: Os autores concluíram que o PCR multiplex do LCR pode melhorar a velocidade e a precisão do diagnóstico de meningite bacteriana em um ambiente clínico como complemento aos ensaios imunológicos e bacteriológicos clássicos no LCR. Também é útil para meningite bacteriana aguda com cultura de LCR negativa.

Ralstonia mannitolilytica bacteremia in a neonatal intensive care unit

Abstract Ralstonia mannitolilytica, a Gram-negative bacterium, is rarely isolated in clinical laboratories. It has been associated with outbreaks due to its ability to survive in liquid media and hospital devices. We describe three cases of bacteremia caused by R. mannitolilytica in a neonatal intensive care unit in Curitiba, Southern Brazil. All isolates presented the same PFGE profile. The common source of infection was undetected in surveillance cultures for the outbreak survey. All patients received antimicrobial treatment and were discharged from the maternity. Due to the characteristics of the microorganism, clinicians and microbiologists should pay attention to the emergence of Ralstonia spp. infections.

Is it possible to perform bacterial identification and antimicrobial susceptibility testing with a positive blood culture bottle for quick diagnosis of bloodstream infections?

Abstract INTRODUCTION: Bloodstream infections can be fatal, and timely identification of the etiologic agent is important for treatment. METHODOLOGY: An alternative method, consisting of direct identification and susceptibility testing of blood culture bottles using the automated VITEK 2® system, was assessed. RESULTS: All 37 of the Gram-negative bacilli (GNB) identifications and 57.1% of the 28 Gram-positive cocci (GPC) identifications matched those obtained with standard methods. In susceptibility testing, the agreement was greater than 90%. CONCLUSIONS: This alternative methodology may assist in the early identification and susceptibility testing of GNB. Further research is necessary to develop appropriate methods for GPC.

Distribution of extended-spectrum β-lactamase types in a Brazilian tertiary hospital

INTRODUCTION: Epidemiological data on the prevalence of extended-spectrum β-lactamases (ESBLs) are scarce in Brazil despite the fact that these data are essential for empirical treatment and control measures. The objective of this study was to evaluate the prevalence of different ESBLs by type and distribution in a tertiary hospital in southern Brazil. METHODS: We evaluated 1,827 enterobacterial isolates between August 2003 and March 2008 isolated from patients at a tertiary hospital. Samples were identified using a Vitek automated system and were confirmed by biochemical testing. The identified ESBL strains were characterized by phenotypic methods, polymerase chain reaction (PCR), and sequencing. Genetic similarities were evaluated by pulsed-field gel electrophoresis. RESULTS: It was 390 (21.3%) ESBL-producing strains, which expressed the ESBLs CTX-M (292), SHV (84), CTX and SHV (10), TEM (2), and PER (2). CONCLUSIONS: The prevalence of ESBL-expressing strains was high, especially in Klebsiella pneumoniae and Enterobacter spp. CTX-M was the predominant type of ESBL observed, and its genetic variability indicates a polyclonal distribution. .

Tipagem molecular e resistência aos antimicrobianos em isolados de Escherichia coli de frangos de corte e de tratadores na região metropolitana de Curitiba, Paraná / Molecular typing and antimicrobial resistance in isolates of Escherichia coli from poultry and farmers in the metropolitan region of Curitiba, Paraná

Este estudo verificou o perfil de resistência aos antimicrobianos entre isolados de Escherichia coli de frangos de corte de criação intensiva e de subsistência e dos respectivos tratadores e a similaridade genotípica entre isolados de E.coli de frangos de corte de criação intensiva e isolados de E. coli de tratadores de frangos de criação intensiva pela técnica de Eletroforese em Gel de Campo Pulsado (PFGE). 60 amostras de fezes de frangos de criação intensiva, 60 de frangos de corte de criação de subsistência (caipira) e 20 amostras dos tratadores de frangos de criação intensiva e 20 de tratadores de frangos de criação de subsistência. E. coli foram isoladas, identificadas e submetidas ao teste de suscetibilidade a 12 antimicrobianos. Pela PFGE foram analisados 24 isolados de E. coli de frangos de corte de criação intensiva e oito de tratadores. Em isolados E. coli de frangos de criação intensiva a resistência para a ampicilina foi de 100%, cefotaxima 43%, ceftriaxona 48%, ácido nalidíxico 62%, enrofloxacina 23%, ciprofloxacina 23%, tetraciclina 83% e 45% para trimetoprim-sulfametoxazol. Nos isolados de frangos de criação de subsistência foi de 20%, 0%, 0%, 5%, 2%, 4%, 33% e 8%, respectivamente...

This study examined the profile of antimicrobial resistance among isolates of Escherichia coli from poultry intensive farming and free-range systems and their farmers. For technique of Gel Electrophoresis Pulsed Field (PFGE) examined the similarity between isolates from poultry intensive farming and their farmers. From 60 samples of poultry feces from intensive farming systems, 60 of free-range extensive systems and 20 of farmers of each segment, the E. coli was isolated and submitted to the test of susceptability to 12 antimicrobials. 24 isolates of E. coli of poultry from intensive farming systems and eight E. coli isolates from farmers poultry intensive farming were analyzed via technique of PFGE. In intensive farming systems poultry, 100% resistence to ampicillin was verified, 43% to cefotaxime, 48% to ceftriaxone, 62% to nalidixic acid, 23% to enrofloxacin, 23% to ciprofloxacin, 83% to tetracycline and 45% to trimetroprim-sulfametoxazol. In the strains of free-range extensive systems, resistance was 20%, 0%, 0%, 5%, 2%, 4%, 33% and 8%, respectively...

Characterization of virulence genes cagA and vacA in Helicobacter Pylori and their prevalence in gastrointestinal disorders

Prevalence of H. pylori infection was determined using cultures of gastric biopsy samples of patients attended at the academic hospital of the Federal University of Paraná, Curitiba, Paraná, Brazil. Molecular methods were used to characterize the cagA and vacA genes from bacterial isolates associated with different diseases presented by patients. Out of a total of 81, forty-two gastric biopsy samples tested were positive for H. pylori, with a prevalence of 51.9 percent. No significant difference was found with regard to the gender (p=0.793) and age (p=0.183) of the patients. Genotype s1m1 vacA gene was found in 67 percent of the cases of peptic ulcer investigated (p=1.0), despite the limited number of patients with this disease (n=3). A correlation between the presence of less virulent strains (s2m2) and reflux esophagitis was found in the majority of the cases (45 percent), but without statistical significance. An association between the prevalence of cagA gene, found in 92 percent of isolates, and peptic ulcer was not observed (p=1.0), suggesting that this gene cannot be considered a specific marker of severity in our environment. The results reinforce the importance of conducting regional studies and the need to characterize H. pylori virulence genes associated with different diseases.

Cefepime versus extended spectrum β-lactamase-producing Enterobacteriaceae

The objective of this study was to evaluate the susceptibility to cefepime of a large group of ESBL- producing enterobacteria recently isolated in a Brazilian teaching hospital . The study included 280 strains of ESBL-producing enterobacteria, isolated between 2005 and 2008. The presence of the genes blaCTX-M, blaTEM and blaSHV was determined by PCR and confirmed by nucleotide sequencing. Susceptibility testing for cefepime was performed by disc-diffusion, agar dilution method and E-test®. Among the isolates, 34 (12.1 percent) presented a cefepime inhibition zone > 21 and MIC < 8 mg/L by agar dilution and E-strip methods. The use of cefepime for the treatment of infections caused by ESBL-producing bacteria has been controversial. Some studies of PD/PK show the probability of achieving the required PD parameters for cefepime, when the MICs were < 8 mg/L, whereas others have reported therapeutic failure with the same MIC. Additional data is essential to come to terms about the report and treatment with cefepime in ESBL-producing organisms especially when these microorganisms are isolated from sterile sites and from critically ill patients.

Resistência à fluoroquinolonas em Escherichia coli isoladas em cultura de urina / Resistance to fluoroquinolones in Escherichia coli isolated from urine culture

A infecção do trato urinário é uma das infecções mais comuns na prática clínica, sendo Escherichia coli o principal agente etiológico. As fluoroquinolonas são agentes antimicrobianos de amplo espectro utilizados na terapia empírica destas infecções, porém a resistência a estes fármacos vem aumentando de forma preocupante em todo o mundo. Neste estudo avaliou-se o perfil de susceptibilidade às fluoroquinolonas em amostras de Escherichia coli isoladas de culturas de urina, pelo metoda de disco-difusao, segundo CLSI 2009. Foram testados ciprofloxacino, levofloxacino, gatifloxacino e norfloxacino. Das 167 amostras de E. coli, 49 (29,3%) foram consideradas resistentes a pelo menos uma quinolona testada. Os resultados demonstram a necessidade do conhecimento de padrões de resistência a fim de aperfeiçoar o tratamento.

Urinary tract infection is the most common infections in pratical clinical. Escherichia coli is also the main etiologic agent. The fluoroquinolones are broad-spectrum antibacterial agents used in the empirical theraphy of these infections. Antimicrobial resistance has been increasing in worldwide. This study evaluated the profile susceptibility to fluoroquinolones in samples of Escherichia coli isolated from urine culture. Used the method was disk diffusion. The following fluoroquinolones has been tested: ciprofloxacin, levofloxacin, gatifloxacin and norfloxacin. In a total of 167 E. coli samples, 49 (29,3%) had been considered resistant at least one quinolone tested. Based on these preliminary results, likely resistance standards are recomended in order to obtain a perfect treatment.

Anti-Helicobacter pylori activity of plant extracts traditionally used for the treatment of gastrointestinal disorders

The antibacterial activity of plant extracts obtained from Bixa orellana L., Chamomilla recutita L., Ilex paraguariensis A. St.-Hil., Malva sylvestris L., Plantago major L. and Rheum rhaponticum L. has been evaluated against two reference strains and eleven clinical isolates of Helicobacter pylori. All the plant species chosen are used in popular Brazilian cuisine and folk medicine in the treatment of gastrointestinal disorders. Initial screening was made by the disk diffusion test and then minimum inhibitory concentration was determined by the agar dilution method. The results presented in this work demonstrated that among the plant preparations analyzed, B. orellana L., C. recutita L., I. paraguariensis A. St.-Hil. and M. sylvestris L. were capable of inhibiting the in vitro growth of H. pylori.

Occurrence of extended-spectrum beta-lactamases in Enterobacteriaceae isolated from hospitalized patients in Curitiba, southern Brazil

Production of extended-spectrum beta-lactamases (ESBL) by enterobacteria is an important resistance mechanism against antimicrobial beta-lactamics. We tested 498 bacterial strains isolated from two tertiary-care teaching hospitals for ESBL production, using screening breakpoints for aztreonam and third generation cephalosporins, according to CLSI recommendations. Among these isolates, 155 were positive for the ESBL screening test, and 121 (78 percent) were confirmed by the clavulanic acid combination disk method. We found a high frequency of ESBL (24 percent) among Enterobacteriaceae, with a frequency of 57.4 percent for Klebsiella pneumoniae, 21.4 percent for Klebsiella oxytoca, and 7.2 percent for E. coli. In other members of Enterobacteriaceae, non-Klebsiella and non-E. coli, the prevalence was 21.6 percent. Ceftriaxone and cefotaxime showed a higher sensitivity in the screening test (99.2 percent) when compared to ceftazidime, aztreonam and cefpodoxime. However, cefotaxime/cefotaxime plus clavulanic acid showed a higher sensitivity in the confirmatory test (96.7 percent).