Detection of resistance genes in pyometra isolated bacteria in bitches / Detecção de genes de resistência em bactérias isoladas de piometra em cadelas

Pyometra has several immunological and molecular changes that are responsible for uterine inflammation and the disease may or may not have infections. This study aimed to isolate and identify bacteria in the uterine content of bitches with pyometra, to analyze the susceptibility profile to antibiotics, detect ß-lactamase enzyme production by phenotypic tests, and resistance genes to ß-lactams. Eighteen samples of uterine content were collected by aspiration puncture. The samples were inoculated in bacteriological media and identified by biochemical tests. Subsequently, antibiogram tests, screening for detection of ß-lactamases, and Real-Time PCR for detection of resistance genes was performed. Escherichia coli, Klebsiella spp., Enterobacter aerogenes, Citrobacter spp., Staphylococcus spp., and Streptococcus spp. were identified in the analyzed samples of uterine content. In the antibiogram test, 90.5% of the isolates showed resistance to at least one antibiotic, and of these, 36.8% were considered MDR, with three Staphylococcus spp., three E. coli, and one Klebsiellaspp. Concerning bacterial resistance to the groups of antibiotics tested, 38.1% of the isolates were resistant to at least one type of ß-lactam, 33.3% to tetracycline, 19.0% to aminoglycosides, and 14.3% to fluoroquinolones, macrolides, and trimethoprim-sulfamethoxazole. In the phenotypic test to detect ß-lactamase production, E. coli samples were negative and Klebsiella spp. was positive for the production of AmpC, which presented the blaCMY, blaSPM, and blaSIM genes. Bacteria that are resistant to antibiotics represent a great challenge and laboratory support is therefore essential, without which therapeutic success decreases and death may be inevitable.(AU)

A piometra apresenta diversas alterações imunológicas e moleculares que são responsáveis pela inflamação uterina, e a doença pode ser infecciosa ou não. O objetivo deste estudo foi isolar e identificar bactérias no conteúdo uterino de cadelas com piometra, analisar o perfil de suscetibilidade aos antibióticos, detectar a produção de enzimas ß-lactamase por testes fenotípicos e genes de resistência aos ß-lactâmicos. Dezoito amostras de conteúdo uterino foram coletadas por punção aspirativa. As amostras foram inoculadas em meio bacteriológico e identificadas por testes bioquímicos. Posteriormente, foram realizados testes de antibiograma, triagem para detecção de ß-lactamases e PCR em tempo real para detecção de genes de resistência. Escherichia coli, Klebsiella spp., Enterobacter aerogenes, Citrobacter spp., Staphylococcus spp. e Streptococcus spp. foram identificados nas amostras de conteúdo uterino analisadas. No teste de antibiograma, 90,5% dos isolados apresentaram resistência a pelo menos um antibiótico, e destes, 36,8% foram considerados MR, sendo três Staphylococcus spp., três E. coli e uma Klebsiella spp. Sobre a resistência bacteriana aos grupos de antibióticos testados, 38,1% dos isolados foram resistentes a pelo menos um tipo de ß-lactâmico, 33,3% à tetraciclina, 19,0% aos aminoglicosídeos e 14,3% às fluorquinolonas, macrolídeos e trimetoprim-sulfametoxazol. No teste fenotípico para detecção da produção de ß-lactamase, as amostras de E. coli foram negativas, e Klebsiella spp. foi positiva para a produção de AmpC, que apresentou os genes blaCMY, blaSPM e blaSIM. As bactérias resistentes aos antibióticos representam um grande desafio e, portanto, o suporte laboratorial é essencial, sem o qual o sucesso terapêutico diminui e a morte pode ser inevitável.(AU)

An emerging threat of ceftriaxone-resistant non-typhoidal salmonella in South India: Incidence and molecular profile

Background: Non-typhoidal Salmonella (NTS) infection is a serious public health problem globally. Although NTS infections are self-limited, antimicrobial therapy is recommended for severe infections and immunocompromised patients. Antimicrobial resistance (AMR) in these pathogens further limits its therapeutic options. Here, we report an incidence of ceftriaxone resistance in NTS over the past 9 years in a southern Indian region. Materials and Methods: Molecular mechanisms of resistance in ceftriaxone-resistant NTS have been tested by both phenotypic and molecular methods. Minimum inhibitory concentration was determined by the E-test and broth microdilution method. AMR gene markers of ?-lactamases such as AmpCs (blaMOX, blaCMY, blaDHA, blaFOX, blaACC and blaACT) and extended-spectrum ?-lactamases (ESBLs) (blaSHV, blaTEM, blaVEB, blaPER, blaCTXM-1like,blaCTXM-2like, blaCTXM-8like, blaCTXM-9like and blaCTXM-25like) were screened. The presence of IncH12 and IncI1 plasmid was also analysed. Results: The study reports a 5% prevalence of ceftriaxone resistance in NTS. The most common serogroup was Salmonella Group B followed by Salmonella Group E and Salmonella group C1/C2. The occurrence of blaCTX-M-1, blaTEM, blaCMY and blaSHV genes was observed in 54%, 54%, 48% and 3% of the isolates, respectively. Interestingly, few isolates carried dual resistance genes (ESBLs and AmpCs). IncH12 and IncI1 plasmid was identified in isolates carrying ESBL and AmpC genes, respectively. Conclusion: This study shows that ceftriaxone resistance is mainly mediated by ?-lactamases such as ESBL and AmpC. As the incidence of ceftriaxone resistance is rising gradually over the years, it is imperative to monitor the AMR in this species.

High occurrence of blaCMY-1 AmpC lactamase producing Escherichia coli in cases of complicated urinary tract infection (UTI) from a tertiary health care centre in north India.

AmpC beta lactamase producing Gram-negative bacteria have emerged worldwide. It is important to distinguish plasmid mediated AmpC β lactamases from chromosomally mediated enzymes for surveillance, epidemiology and hospital infection control as plasmid mediated genes can spread to other organisms. Occurrence of blaCMY-1 AmpC β-lactamase, a plasmid mediated cephamycinase was studied in 100 consecutive isolates of Escherichia coli from cases of complicated urinary tract infection (UTI). Screening for AmpC production was done by modified Hodge test, three dimensional test and AmpC disk test. All isolates showing a positive result by 2 out of 3 tests were then tested for blaCMY-1 gene by PCR. Fifty nine isolates were positive for AmpC β lactamase production, 56.6 per cent were positive by PCR. Eight out of 13 isolates which were negative by EDTA disk method were positive by PCR, whereas none of the isolates negative by 3D and modified Hodge test was positive by PCR. Among admitted patients urinary catheterisation was the major risk factor followed by obstructive uropathy, three patients developed urosepsis. High occurrence of blaCMY-1 AmpC β-lactamase warrants health care workers to endorse good hospital practices.

Prevalence and Mechanism of Third-Generation Cephalosporins-Resistant Escherichia coli and Klebsiella pneumoniae Strains Isolated from Clinical Specimen / 대한임상미생물학회지

BACKGROUND: Among Gram-negative pathogens in Korea, the incidence of resistance to thirdgeneration cephalosporins is becoming an ever-increasing problem. This study was designed to determine the prevalence of third-generation cephalosporins-resistant Escherichia coli and Klebsiella pneumoniae isolates from patients in a tertiary care hospital in Busan, Korea, and to characterize the mechanism of resistance. METHODS: A total of 710 E. coli and 237 K. pneumoniae non-duplicate isolates were collected from patients in Kosin Medical Center in 1999. Antimicrobial susceptibilities were tested by the disk diffusion method. Extended-spectrum beta-lactamase (ESBL) production was determined by the double disk synergy test. MICs were determined by the agar dilution method. Searches for blaTEM, blaSHV, and blaCMY genes in cefotaxime-resistant or intermediate isolates were performed by PCR amplification. PCR products were used to determine the sequence of resistance genes by the dideoxy-chain termination method. RESULTS: Seven percent of E. coli and 25% of K. pneumoniae isolates were resistant to cefotaxime. Among the isolates with decreased susceptibility to cefotaxime, 69% (18/26) of E. coli and 80% (20/25) of K. pneumoniae isolates showed positive results in double disk synergy test. Banding patterns of PCR amplification showed that the blaTEM, blaSHV, and blaCMY genes were harboured by 71% (20/28), 86% (24/28) and 14% (4/28) of isolates with decreased susceptibility to cefotaxime,respectively. Seventy-one percent (20/28) of the isolates contained more than two types of beta- lactamase genes. Nucleotide sequence analysis of PCR products revealed that blaSHV-12 and blaTEM-1b were the dominant types of beta-lactamase gene. In addition, we also identified blaTEM-52, blaSHV-5, and a new ESBL gene named blaTEM-17b. CONCLUSIONS: Third-generation cephalosporins-resistant E. coli and K. pneumoniae are wide spread in Kosin Medical Center, Busan, Korea. Most of the isolates with decreased susceptibility to cefotaxime had blaTEM and/or blaSHV, and some isolates harboured blaCMY genes that may confer resistance against cephamycins. The spread of these beta-lactamase genes could compromise the future usefulness of third-generation cephalosporins for the treatment of infections caused by E. coli and K. pneumoniae.