RESUMEN
Shiga toxin-producing Escherichia coli (STEC) is one of the most important foodborne pathogens, and the rise of antibiotic resistance to it is a significant threat to global public health. The purpose of this study is to investigate the prevalence, molecular characterization, and antibiotic resistance of STEC isolated from raw meat in Vietnam. The findings in this study showed that the prevalence of STEC in raw beef, pork, and chicken meat was 9.72% (7/72), 5.56% (4/72), and 1.39% (1/72), respectively. The STEC isolates were highly resistant to ampicillin (91.67%) and tetracycline (91.67%), followed by trimethoprim/sulfamethoxazole (83.33%), streptomycin (75%), and florfenicol (66.67%). The incidence of STEC virulence-associated genes, including stx1, stx2, eae, and ehxA, was 8.33% (1/12), 91.67% (11/12), 33.33% (4/12), and 58.33% (7/12), respectively. STEC serogroups O157, O26, and O111 were detected in 3 out of 12 STEC isolates. Two isolates were found to be ESBL producers carrying the blaCTX-M-55 gene, and three isolates were colistin-resistant strains harboring the mcr-1 gene. Notably, a STEC O111 isolate from chicken meat harbored both the blaCTX-M-55 and mcr-1 genes.
RESUMEN
E. coli is an important zoonotic pathogen capable of causing foodborne illness and bovine mastitis. Bacteriophages have been increasingly considered a promising tool to control unwanted bacteria. The aim of this study is to determine the antibiotic resistance profile of E. coli isolated from raw milk and the efficacy of phage in controlling multidrug-resistant E. coli in raw milk. Antibiotic susceptibility testing showed the highest resistance rates of E. coli isolates to co-trime (27.34%) and ampicillin (27.34%), followed by streptomycin (25.18%), tetracycline (23.02%), and the lowest resistance rates to ciprofloxacin, gentamycin, and ceftazidime, all at a rate of 2.16%. All isolates were susceptible to meropenem. Of the 139 E. coli isolates, 57 (41.01%) were resistant to at least one antibiotic, and 35 (25.18%) were classified as MDR strains. Molecular characterization indicated that 5 (3.6%) out of the 139 isolates were STEC strains carrying stx1 gene. Seven (5.04%) isolates were phenotypically identified as ESBLEC, and four isolates (2.88%) were resistant to colistin. The results of the genotypic test revealed that four out of seven ESBLEC strains carried both blaTEM and blaCTX-M-1, two harbored blaTEM, and one possessed blaCTX-M-1, while mcr-1 was detected in all four colistin-resistant E. coli isolates. In particular, one isolated E. coli strain (EM148) was determined to be a multidrug-resistant strain simultaneously carrying blaTEM, blaCTX-M-1, and mcr-1. A total of eight phages were successfully recovered from raw milk. The application of phage PEM3 significantly reduced viable counts of multidrug-resistant host EM148 in raw milk by at least 2.31 log CFU/mL at both 24 °C and 4 °C.
RESUMEN
Clostridium perfringens is one of the most important zoonotic pathogens as it can cause food poisoning in humans and necrotic enteritis in both animals and humans. Meat, especially pork and chicken meat, is considered the main vehicle for the transmission of C. perfringens from animals to humans. The purpose of this study was to determine the prevalence, toxinotype, and antimicrobial resistance profile of C. perfringens isolated from pork and chicken meat sold in Vietnam. The isolation results showed that 15/50 (30%) of pork samples and 8/50 (16%) of chicken meat samples were contaminated with C. perfringens. The isolates exhibited their highest resistance rate to tetracycline (21/23; 91.30%) and clindamycin (10/23; 43.48%). On the contrary, their lowest resistance rates were observed in response to imipenem (2/23; 8.70%) and cefoxitin (1/23; 4.35%). In particular, 34.78% (8/23) of C. perfringens isolates were identified to be multidrug-resistant strains. The results of toxin genotyping indicated that all isolates were positive for the cpa gene and belonged to type A.
RESUMEN
African swine fever (ASF) has been considered as one of the most important and devastating swine diseases with high mortality rates. Since effective vaccines and treatment are not available, mass euthanasia of infected and exposed pigs has been known to be the best measure to control ASF. Although composting has been proved to be a safe method for the rapid disposal of animal carcasses during outbreaks, there is no information about the effect of composting on the viability of ASF virus in swine carcasses. This study investigates the survival of the ASF virus in swine carcasses during composting. The findings suggested that the DNA of the ASF virus was detected in all samples tested. On the contrary, infectious ASF virus particles were rapidly destroyed at day 3.