Polymerase chain reaction and loop-mediated isothermal amplification targeting lic13162, lic20239, and lipL32 genes for leptospirosis diagnosis.

Leptospirosis is a zoonotic disease caused by pathogenic species of Leptospira. Due to the similarity with clinical signs of other febrile diseases, early diagnosis remains challenging. Real-time PCR has been used for direct detection of Leptospira, but it requires thermocyclers and highly trained personnel. Loop-mediated isothermal amplification (LAMP) is a simple and rapid DNA-based assay. Therefore, here we have developed PCR and LAMP assays targeting two novel genes, lic13162 and lic20239, and also lipL32 gene to detect pathogenic Leptospira. Analytical and diagnostic performances were compared with bacterial isolates (including different Leptospira species and serovars) and clinical samples. The results demonstrated that PCR assays targeting lic13162 and lic20239 were successful to amplify Leptospira, but LAMP not. However, both PCR and LAMP targeting lipL32 could detect pathogenic Leptospira. LAMP lipL32 could be performed in 30 min with a detection limit of 156 cells/mL. Diagnostic performance of lipL32-LAMP presented 84.2% sensitivity and 93.2% specificity. In conclusion, lipL32 PCR and LAMP are effective methods to detect pathogenic Leptospira directly from clinical samples.

Salmonella isolates from urine cultures: serotypes and antimicrobial resistance in hospital settings.

This study investigated the serotypes and antimicrobial resistance of Salmonella isolates in urine cultures from 38 hospitalized patients. Nine serotypes were detected, and a large proportion was Typhimurium and Enteritidis. The strains presented resistance to 11 different antibiotics. Thirteen isolates (11 from serotype Typhimurium) exhibited multidrug resistance.

Increasing prevalence and dissemination of invasive nontyphoidal Salmonella serotype Typhimurium with multidrug resistance in hospitalized patients from southern Brazil

ABSTRACT Introduction: Nontyphoidal Salmonella serotypes are the main cause of human food-borne infection, including several hospitalization cases in the developing countries. Aim: To detect the main serotypes and to characterize the antibiotic resistance of human non-enteric and enteric nontyphoidal Salmonella from clinical isolates in Brazil. Methods: Salmonella serotypes were identified by microbiological and molecular methods. Susceptibility testing to antibiotics was performed by agar disk diffusion. Real-time PCRs were carried out for the detection of the genus Salmonella as well as serotypes Typhimurium and Enteritidis. Results: A total of 307 nontyphoidal Salmonella were isolated from 289 different patients in a reference laboratory (LACEN-RS) from Southern Brazil in a six-year period (2010-2015). There were 45 isolates from emerging cases and 244 from sporadic cases in hospitalized patients. Non-enteric isolates were detected in 42.6% of the patients from sources such as urine, blood and other clinical fluids. Serological and PCR-specific tests demonstrated that Typhimurium (48.4%) and Enteritidis (18.3%) were the most frequent serotypes. Typhimurium isolates were generally resistant to three or more antibiotic classes, while Enteritidis isolates to one or two classes. Typhimurium was the most frequent serotype in all samples (48.4%), mainly among the hospitalized patients (55.6%), and presented the highest rates of multidrug resistance (59.3% of the isolates of this serotype). Further, the prevalence of this serotype increased along the years of the study in comparison to other nontyphoidal Salmonella serotypes. Conclusion: Greater public health attention should be given to prevent salmonellosis in the community and in hospital settings to reduce the rates of Typhimurium strains with multidrug resistance.

Increasing prevalence and dissemination of invasive nontyphoidal Salmonella serotype Typhimurium with multidrug resistance in hospitalized patients from southern Brazil.

INTRODUCTION: Nontyphoidal Salmonella serotypes are the main cause of human food-borne infection, including several hospitalization cases in the developing countries. AIM: To detect the main serotypes and to characterize the antibiotic resistance of human non-enteric and enteric nontyphoidal Salmonella from clinical isolates in Brazil. METHODS: Salmonella serotypes were identified by microbiological and molecular methods. Susceptibility testing to antibiotics was performed by agar disk diffusion. Real-time PCRs were carried out for the detection of the genus Salmonella as well as serotypes Typhimurium and Enteritidis. RESULTS: A total of 307 nontyphoidal Salmonella were isolated from 289 different patients in a reference laboratory (LACEN-RS) from Southern Brazil in a six-year period (2010-2015). There were 45 isolates from emerging cases and 244 from sporadic cases in hospitalized patients. Non-enteric isolates were detected in 42.6% of the patients from sources such as urine, blood and other clinical fluids. Serological and PCR-specific tests demonstrated that Typhimurium (48.4%) and Enteritidis (18.3%) were the most frequent serotypes. Typhimurium isolates were generally resistant to three or more antibiotic classes, while Enteritidis isolates to one or two classes. Typhimurium was the most frequent serotype in all samples (48.4%), mainly among the hospitalized patients (55.6%), and presented the highest rates of multidrug resistance (59.3% of the isolates of this serotype). Further, the prevalence of this serotype increased along the years of the study in comparison to other nontyphoidal Salmonella serotypes. CONCLUSION: Greater public health attention should be given to prevent salmonellosis in the community and in hospital settings to reduce the rates of Typhimurium strains with multidrug resistance.

COMPARISON BETWEEN FOUR USUAL METHODS OF IDENTIFICATION OF Candida SPECIES.

Infection by Candida spp. is associated with high mortality rates, especially when treatment is not appropriate and/or not immediate. Therefore, it is necessary to correctly identify the genus and species of Candida. The aim of this study was to compare the identification of 89 samples of Candida spp. by the manual methods germ tube test, auxanogram and chromogenic medium in relation to the ID 32C automated method. The concordances between the methods in ascending order, measured by the Kappa index were: ID 32C with CHROMagar Candida(κ = 0.38), ID 32C with auxanogram (κ = 0.59) and ID 32C with germ tube (κ = 0.9). One of the species identified in this study was C. tropicalis,which demonstrated a sensitivity of 46.2%, a specificity of 95.2%, PPV of 80%, NPV of 81.1%, and an accuracy of 80.9% in tests performed with CHROMagar Candida;and a sensitivity of 76.9%, a specificity of 96.8%, PPV of 90.9%, NPV of 91%, and an accuracy of 91% in the auxanogram tests. Therefore, it is necessary to know the advantages and limitations of methods to choose the best combination between them for a fast and correct identification of Candida species.

Comparison between four usual methods of identification of candida species / Comparação entre quatro métodos usuais de identificação de espécies de Candida

SUMMARYInfection by Candidaspp. is associated with high mortality rates, especially when treatment is not appropriate and/or not immediate. Therefore, it is necessary to correctly identify the genus and species of Candida. The aim of this study was to compare the identification of 89 samples of Candidaspp. by the manual methods germ tube test, auxanogram and chromogenic medium in relation to the ID 32C automated method. The concordances between the methods in ascending order, measured by the Kappa index were: ID 32C with CHROMagar Candida(κ = 0.38), ID 32C with auxanogram (κ = 0.59) and ID 32C with germ tube (κ = 0.9). One of the species identified in this study was C. tropicalis,which demonstrated a sensitivity of 46.2%, a specificity of 95.2%, PPV of 80%, NPV of 81.1%, and an accuracy of 80.9% in tests performed with CHROMagar Candida;and a sensitivity of 76.9%, a specificity of 96.8%, PPV of 90.9%, NPV of 91%, and an accuracy of 91% in the auxanogram tests. Therefore, it is necessary to know the advantages and limitations of methods to choose the best combination between them for a fast and correct identification of Candidaspecies.

RESUMOA infecção por Candidaspp. está associada com alta mortalidade, principalmente quando o tratamento não é adequado, nem imediato. Assim, a correta identificação do gênero e espécie é necessária. O objetivo deste trabalho foi comparar 89 amostras de Candidaspp. pelos métodos manuais prova do tubo germinativo, auxanograma e CHROMagar em relação ao método automatizado ID 32C. As concordâncias entre os métodos em ordem crescente, medidas pelo coeficiente de Kappa, foram: ID 32C com CHROMagar Candida(κ = 0,38), ID 32C com auxanograma (κ = 0,59) e ID 32C com tubo germinativo (κ = 0,9). Uma das espécies identificadas neste trabalho foi a C. tropicalis, que demonstrou uma sensibilidade de 46,2%, especificidade de 95,2%, VPP de 80%, VPN de 81,1% e acurácia de 80,9% nos testes com CHROMagar Candidae uma sensibilidade de 76,9%, especificidade de 96,8%, VPP de 90,9%, VPN de 91% e acurácia de 91% nos testes de auxanograma. Portanto, o conhecimento das vantagens e limitações dos métodos é necessário para a escolha da melhor combinação entre os mesmos visando uma rápida e correta identificação das espécies de Candida.