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INTRODUCTION: Novel beta-lactam/beta-lactamase inhibitor (BIBLI) combinations are commercially available and have been used for treating carbapenem-resistant Klebsiella pneumoniae (CRKP) infections. Continuous surveillance of susceptibility profiles and resistance mechanism identification are necessary to monitor the evolution of resistance within these agents. OBJECTIVE: The purpose of this study was to evaluate the susceptibility rates of ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam in CRKP isolated from patients with bloodstream infections who underwent screening for a randomized clinical trial in Brazil. METHODS: Minimum inhibitory concentrations (MICs) were determined for meropenem, ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam using the gradient diffusion strip method. Carbapenemase genes were detected by multiplex real-time polymerase chain reaction. Klebsiella pneumoniae carbapenemase (KPC)-producing isolates showing resistance to any BLBLI and New Delhi Metallo-beta-lactamase (NDM)-producing isolates with susceptibility to any BLBLI isolates were further submitted for whole-genome sequencing. RESULTS: From a total of 69 CRKP isolates, 39 were positive for blaKPC, 19 for blaNDM and 11 for blaKPC and blaNDM. KPC-producing isolates demonstrated susceptibility rates above 94â¯% for all BLBLIs. Two isolates with resistance to meropenem/vaborbactam demonstrated a Gly and Asp duplication at the porin OmpK36 as well as a truncated OmpK35. All NDM-producing isolates, including KPC and NDM coproducers, demonstrated susceptibility rates to ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam of 0â¯%, 9.1-21.1â¯% and 9.1-26.3â¯%, respectively. Five NDM-producing isolates that presented susceptibility to BLBLIs also had porin alterations CONCLUSIONS: This study showed that, although high susceptibility rates to BLBLIs were found, KPC-2 isolates were able to demonstrate resistance probably as a result of porin mutations. Additionally, NDM-1 isolates showed susceptibility to BLBLIs in vitro.
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Antibacterianos , Compostos Azabicíclicos , Enterobacteriáceas Resistentes a Carbapenêmicos , Ceftazidima , Combinação de Medicamentos , Infecções por Klebsiella , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Inibidores de beta-Lactamases , beta-Lactamases , Humanos , Brasil , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Inibidores de beta-Lactamases/farmacologia , Infecções por Klebsiella/microbiologia , Compostos Azabicíclicos/farmacologia , Ceftazidima/farmacologia , beta-Lactamases/genética , Antibacterianos/farmacologia , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Proteínas de Bactérias/genética , Meropeném/farmacologia , Imipenem/farmacologia , Bacteriemia/microbiologia , Ácidos Borônicos/farmacologia , Compostos Heterocíclicos com 1 AnelRESUMO
Antimicrobial treatment of patients with bloodstream infections (BSI) is time-sensitive. In an era of increasing antimicrobial resistance, rapid detection and identification of bacteria with antimicrobial susceptibility are critical for targeted therapy early in the disease course. This study describes the performance of a rapid method for identifying and testing antimicrobial susceptibility of Gram-negative bacteria performed directly from blood culture bottles in a routine microbiology laboratory. A total of 284, 120, and 24 samples were analyzed by rapid identification (Rid), rapid susceptibility testing (RAST), and rapid broth microdilution for polymyxin B (rMIC), respectively, and compared with standard methods. Our protocol was able to identify 93% of isolates at the species level using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We obtained 100% agreement for RAST compared to the standard method and 96% agreement for rMIC. Our protocol has proven to be an excellent tool for rapid identification of Gram-negative bacilli causing BSIs. It can also be used in microbiology laboratory routine along with RAST and faster polymyxin microdilution, especially for carbapenemase-producing bacteria, allowing for rapid, simple, accurate, and cost-effective diagnosis.
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Anti-Infecciosos , Bacteriemia , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Hemocultura/métodos , Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Bactérias , Bactérias Gram-NegativasRESUMO
Abstract Antimicrobial treatment of patients with bloodstream infections (BSI) is time-sensitive. In an era of increasing antimicrobial resistance, rapid detection and identification of bacteria with antimicrobial susceptibility are critical for targeted therapy early in the disease course. This study describes the performance of a rapid method for identifying and testing antimicrobial susceptibility of Gram-negative bacteria performed directly from blood culture bottles in a routine microbiology laboratory. A total of 284, 120, and 24 samples were analyzed by rapid identification (Rid), rapid susceptibility testing (RAST), and rapid broth microdilution for polymyxin B (rMIC), respectively, and compared with standard methods. Our protocol was able to identify 93% of isolates at the species level using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We obtained 100% agreement for RAST compared to the standard method and 96% agreement for rMIC. Our protocol has proven to be an excellent tool for rapid identification of Gram-negative bacilli causing BSIs. It can also be used in microbiology laboratory routine along with RAST and faster polymyxin microdilution, especially for carbapenemase-producing bacteria, allowing for rapid, simple, accurate, and cost-effective diagnosis.
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PURPOSE: To evaluate filter paper as a means to transport oro/nasopharyngeal samples from laboratories with few resources for SARS-CoV-2 detection by RT-qPCR in a central laboratory that usually performs this technique as routine. METHODS: A total of 40 specimens were evaluated in parallel by RT-qPCR carried out after RNA extraction using two different protocols: direct RNA extraction (Protocol A - reference method) and RNA extraction after impregnation in filter paper (Protocol B). RESULTS: The RT-qPCR for SARS-CoV-2 using Protocol B presented 97.22% (35/36) of agreement for SARS-CoV-2-positive samples when compared to the reference method (Protocol A), even for specimens with low viral load (increased Ct values). Noteworthy, three clinical specimens which were categorized as inconclusive by Protocol A presented amplification of both N1 and N2 targets using Protocol B, presenting positive results for SARS-CoV-2. CONCLUSION: The use of filter paper to transport oro/nasopharyngeal clinical samples presented very satisfactory results to detect SARS-CoV-2 by RT-qPCR. In addition, it proved to be a feasible and sensitive approach, being able to generate the detection of SARS-CoV-2 even at low concentrations, without presenting false-negative results.
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COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Teste para COVID-19 , Técnicas de Laboratório Clínico/métodos , Humanos , RNA Viral/análise , RNA Viral/genética , SARS-CoV-2/genética , Sensibilidade e EspecificidadeRESUMO
Determination of the susceptibility profile of isolates of Candida from blood culture bottles is extremely important for correctly guiding patient pharmacotherapy. The aim of this study was to compare the results of analysis of Candida isolated directly from blood culture bottles by the VITEK MS MALDI-TOF identification system and the fluconazole disk diffusion assay with those of standard identification methods. Testing directly from the bottle allowed results 24 to 48 hours quicker than the standard method. There was a categorical agreement of 51.64% (47 of 91 samples) between the results of analysis directly from the bottle and analysis by the standard method. Regarding species identification, there was 96.15% agreement for Candida parapsilosis (25 of 26 samples). Categorical agreement between the rapid and standard disk diffusion methods was 95%, and the agreement between the rapid disk diffusion method and the broth microdilution method was 97%. Only minor errors in the rapid method were observed: 3 (5%) in the standard disk diffusion method and 2 (3%) in the broth microdilution method. Our study concluded that the rapid disk diffusion method for fluconazole is a fast, easy, reproducible, and consistent method. Its timely implementation for testing antifungal agents in the clinical microbiology laboratory can help reduce profile release times, thus helping to determine the most appropriate antifungal treatment.
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Hypermutable (HPM) strains of Pseudomonas aeruginosa have been found at high frequencies in cystic fibrosis (CF) patients in Europe. We report the results of testing for HPM frequencies, mutator genotype, and antimicrobial resistance of P. aeruginosa strains from Brazilian CF patients. A modified disk diffusion technique was used to quantify antibiotic-resistant subpopulations of an isolate, and estimations of the frequency of mutation to rifampin resistance were determined for 705 isolates from 149 patients attending clinics in two Brazilian cities. Mutations in the mutS gene were detected by sequencing assays. We found 194 (27.5%) HPM isolates in samples from 99 (66.4%) patients. Thirty-five HPM isolates (18.0%) from 31 (31.3%) patients exhibited a high increased spontaneous mutation rate compared with controls, and eight isolates from six patients displayed a defective mutS gene. The dominant HPM population was associated with very low antibiotic resistance levels, while HPM subpopulations were generally more resistant to antimicrobials. A relatively high prevalence of HPM P. aeruginosa in CF patients was associated with surprisingly low antibiotic resistance levels, in contrast to some earlier studies.
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Fibrose Cística/complicações , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/isolamento & purificação , Adolescente , Adulto , Antibacterianos/farmacologia , Brasil , Criança , Pré-Escolar , Cidades , Farmacorresistência Bacteriana , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Proteína MutS de Ligação de DNA com Erro de Pareamento/genética , Mutação , Taxa de Mutação , Pseudomonas aeruginosa/classificação , Pseudomonas aeruginosa/efeitos dos fármacos , Análise de Sequência de DNARESUMO
BACKGROUND: Biofilm production is an important mechanism for bacterial survival and its association with antimicrobial resistance represents a challenge for the patient treatment. In this study we evaluated the in vitro action of macrolides in combination with anti-pseudomonal agents on biofilm-grown Pseudomonas aeruginosa recovered from cystic fibrosis (CF) patients. RESULTS: A total of 64 isolates were analysed. The biofilm inhibitory concentration (BIC) results were consistently higher than those obtained by the conventional method, minimal inhibitory concentration, (MIC) for most anti-pseudomonal agents tested (ceftazidime: P = 0.001, tobramycin: P = 0.001, imipenem: P < 0.001, meropenem: P = 0.005). When macrolides were associated with the anti-pseudomonal agents, the BIC values were reduced significantly for ceftazidime (P < 0.001) and tobramycin (P < 0.001), regardless the concentration of macrolides. Strong inhibitory quotient was observed when azithromycin at 8 mg/L was associated with all anti-pseudomonal agents tested in biofilm conditions. CONCLUSIONS: P. aeruginosa from CF patients within biofilms are highly resistant to antibiotics but macrolides proved to augment the in vitro activity of anti-pseudomonal agents.
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Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Sinergismo Farmacológico , Macrolídeos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Adolescente , Adulto , Criança , Pré-Escolar , Fibrose Cística/complicações , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/isolamento & purificação , Adulto JovemRESUMO
Candidíase Vulvovaginal (CVV) é uma infecção vaginal comum. O constante aumento da incidência da doença pode estar associado a fatores como idade, infecção por HIV, diabetes, uso de métodos hormonais de contracepção e alterações citopatológicas. O objetivo deste estudo foi avaliar a prevalência de Candida sp. em amostras de secreção vaginal no estado do Rio Grande so Sul, no período de 2005 a 2010. Trata-se de um estudo retrospectivo e observacional, por meiodo qual foram avaliados 121.328 relatórios médicos de citopatologia num período de seis anos. Foram constatados 8.582 (7,1por cento) casos positivos de Candida sp.. A idade média das pacientes era de 35 anos. Mais da metade das pacientes (53por cento) usavam anticoncepcional oral e, em 49por cento dos casos, verificou-se a existência de alterações no colo do útero. A continuidade da investigaçãoepidemiológica é necessária para o acompanhamento das tendências ao longo dos anos e para uma melhor compreensão dos fatores que predispõem à CVV no Brasil.