Identification of the bacteria strain and its antibiotic resistance in an epidemic of cholera / 上海预防医学

Objective The present study was conducted to identify the Vibrio cholera type and to analyze its antibiotic resistance in an epidemic of cholera in Haiyan County in 2018, which would provide the references for prevention and control of cholera. Methods Stool samples of the patient and his close contacts as well as the food and environmental samples were collected for identification of the type of Vibrio cholerae and the toxin gene. The resistance of identified Vibrio cholerae to 20 different common antibiotics were tested. Results A total of 176 samples were collected, including 101 stool samples from the case and his close contacts, 35 environmental samples and 40 food samples. Among those samples, only one strain of V. cholerae, O139, was isolated from the patient's first feces sample. It was detected as a toxin gene of ctxA positive by real-time fluorescence PCR. Antibiotic resistance test showed that the strain was sensitive to norfloxacin, levofloxacin, ciprofloxacin, cefotaxime, cephalothin, ampicillin, and amoxicillin. It was 100% resistant to tetracycline, doxycycline, neomycin, kanamycin, streptomycin, and rifampicin. Conclusion V. cholerae O139 strain with ctxA is detected in an epidemic of cholera. Norfloxacin, levofluoxacin and some other antibiotics could be used for clinical treatment and prevention. It should pay attention to this strain of V. cholera regarding the multiple drug resistance and the change of antibiotic resistance.

Análise do perfil de resistência a antibióticos e detecção dos genes de virulência e resistência em Aeromonas provenientes de amostras ambientais / Analysis of antibiotic resistance profile and detection of virulence and resistance genes in Aeromonas from environmental samples

As Aeromonas são bactérias distribuídas predominantemente em meio aquático. São consideradas patógeno emergente, podendo causar doenças em peixes como também no homem. Os problemas mais comuns são a gastrenterite no homem e morte em peixes. OBJETIVO: Este estudo foi desenvolvido para comparar a identificação fenotípica com a genotípica, e também para conhecer o perfil de resistência aos antibióticos em Aeromonas caviae, A. aquariorum, e A. sanarellii isoladas do ambiente aquático e a presença de genes de virulência e resistência. MATERIAL E MÉTODOS: O DNA das 24 cepas em estudo foi extraído por choque térmico e purificado utilizando CTAB. Foram realizadas as PCRs para a detecção dos genes de virulência e dos genes de resistência, após a realização do antibiograma. RESULTADOS: Foram identificadas 4 A. caviae das quais 3(75,0 por cento) apresentaram pelo menos um dos genes act, ast ou alt. Das 3 A. aquariorum, 1(33,3 por cento) apresentaram positividade para os genes act e ast. Entre os 5 isolados de A. sanarellii 1(50,0 por cento) possuíam os genes alt e ast. Seis isolados não foram posicionados taxonomicamente entre as espécies descritas de Aeromonas, e dentre essas um exemplar apresentou o gene alt. Em relação às enzimas MBL e AmpC foram obtidos respectivamente: 3(100 por cento) e 3(100 por cento) em A. aquariorum; 2(50,0 por cento) e 4(100 por cento) em A. caviae; 3(75,0 por cento) e 5(100 por cento) em Aeromonas spp.; 1(20 por cento) e 5(100 por cento) A. sanarellii; Nenhum isolado apresentou resultado positivo, no teste fenotípico, para a produção de ESBL. Com a realização da PCR foi detectada a presença de 5 amostras com gene tipo blaMOX, 21blaCPHA , 17 tipo blaTEM e 2 cepH. CONCLUSÃO: Os resultados sugerem que os isolados podem servir potencialmente como reservatórios de resistência aos antimicrobianos e ainda, que os isolados podem ser considerados patógeno emergentes e significativos para a saúde pública.

Aeromonas spp. is predominantly distributed in the aquatic environment. They are regarded as emerging pathogen, causing disease in fish but also in man. The most common problems are gastroenteritis in humans and death in fish. OBJECTIVE: This study was designed to compare phenotypic with genotypic identification, and also to know the profile of antibiotic resistance in Aeromonas caviae, A. aquariorum, and A. sanarellii isolated from aquatic environment and the presence of virulence genes and resistance. MATERIAL AND METHODS: DNA from 24 strains under study was extracted by thermal shock and purified using CTAB. PCR reactions were performed for the detection of virulence and resistance genes, after the completion of the antibiotic resistance test. RESULTS: We identified four A. caviae from which 3(75.0per cent) had at least one of the genes act, ast or alt. From 3 A. aquariorum, 1(33.3per cent) was positive for the genes act and ast. Among the five isolated A. sanarellii, 1(50.0per cent) had the alt and ast genes Six isolates were not positioned within taxonomically described species of Aeromonas, and among these only one strain presented the alt gene. Regarding the MBL and AmpC it was obtained respectively: 3(100per cent) and 3(100per cent) isolates from A. aquariorum; 2(50.0per cent) and 4(100per cent) isolates from A. caviae; 4(66.7per cent) and 3(50.0per cent) isolates from Aeromonas spp.; and 1(20per cent) and 5 (100per cent) isolates from A. sanarellii. None of the isolates showed positive results in the phenotypic test for ESBL production. The PCR reaction detected the presence of 5 strains with blaMOX-like gene; 21 with blaCPHA gene; 17 with blaTEM-like gene and 2 with cepH gene. CONCLUSION: These findings suggest that the isolates may serve as potential reservoirs of antimicrobial resistance and also that the isolates could be considered emerging pathogens of public health significance.

Susceptibility of different species of animal hosts to Campyelobacter jejuni infection and its drug-resistance / 中国人兽共患病学报

From 2006 to 2008, the susceptibility of different species of animal hosts to Campyebacter jejubni infection was observed in various areas of Jiangsu province, in which the API Campy System was used to perform the biochemical identification and the multiple PCR assay was employed to analyse the C.jejuni isolates from 3010 specimens of fouls. Cattle, pigs and monkeys, and in addition, the susceptibility of isolates to various antibiotics was also determined. In these specimens investigated 402 samples were found to be positive in the detection of C.jejuni with a positive detection rate of 13.36%. The positive detection rates in chicken, water fouls, milk cows, pigs, monkey, red crowned crane and wapiti were 15.83% (258/1630), 10.4% (52/100), 8.24% (42/510), 15.63% (25/160), 15% (15/100), 12.5% (15/80) and 0% (0/30) respectively. Meanwhile, the antibiotics to which the isolates from different hosts showed high rate of sensitivity to 27 antibiotics of 10 varieties included: chloromycetin (100%), Almocylin (99.7%), amicarcin (92.59%), cefprozil (91.67%), alchimycin (90.74%); while the antibiotics to which these isolates showed high rate of resistance were compound neoromin (99.7%), cefoperazone (99.07%), trimethoprim (97.22%), cepronatin (91.67%), cepromondo (99,07%) respectively. It is evident that the susceptibility of different hosts to C.jejuni infection and the status of drug-resistance of the isolates appear to be quite different and more complicated in Jiangsu province.