Antibiotic resistance profiles of Salmonella serovars isolated from retail pork and chicken meat in North Vietnam.

The spread of antibiotic resistance via meat poses a serious public health concerns. During 2007-2009, a total of 586 retail meat samples (318 pork and 268 chicken meats) were collected from three provinces (Bac Ninh, Ha Noi and Ha Tay) of North Vietnam to determine the prevalence of Salmonella. Isolates were characterized by serotyping and antibiotic susceptibility testing. Approximately 39.6% (n=126) of pork and 42.9% (n=115) of chicken samples were Salmonella-positive, and 14 Salmonella serovars were identified. Anatum (15.8%) was the most common serovar, followed by Infantis (13.3%), Emek (10.4%), Derby and Rissen (9.5%), Typhimurium (9.1%), Reading (7.5%) and London (6.2%). The isolation frequency of serovars Enteritidis, Albany, Hadar, Weltevreden, Newport and Blockey ranged from 1.2%-5.8%. Resistance to at least one antibiotic agent was detected in 78.4% of isolates (n=189) and the most frequent resistance were to tetracycline (58.5%), sulphonamides (58.1%), streptomycin (47.3%), ampicillin (39.8%), chloramphenicol (37.3%), trimethoprim (34.0%) and nalidixic acid (27.8%). No Salmonella isolates were resistant to ceftazidime. Chicken isolates had higher resistance to antibiotic agents than pork isolates (P<0.05). It showed that 159 Salmonella isolates belong to the 14 serovars were multidrug resistant (MDR) and 50 MDR patterns were found. This study indicated that Salmonella serovars isolated from retail meat samples were resistant to multiple antibiotics and this resistance was widespread among different serovars. The widespread resistance may have arisen from misuse or overuse of antibiotics during animal husbandry in North Vietnam.

Thai TH ，Hirai T ，Lan NT ，Yamaguchi R ... -  《-》

Molecular characterization of antibiotic-resistant Salmonella isolates from retail meat from markets in Northern Vietnam.

Thai TH ，Yamaguchi R 《-》

Antimicrobial resistance in Salmonella serovars isolated from meat shops at the markets in North Vietnam.

Thai TH ，Lan NT ，Hirai T ，Yamaguchi R ... -  《-》

Prevalence, antibiotic resistance, and extended-spectrum and AmpC β-lactamase productivity of Salmonella isolates from raw meat and seafood samples in Ho Chi Minh City, Vietnam.

Nguyen DT ，Kanki M ，Nguyen PD ，Le HT ，Ngo PT ，Tran DN ，Le NH ，Dang CV ，Kawai T ，Kawahara R ，Yonogi S ，Hirai Y ，Jinnai M ，Yamasaki S ，Kumeda Y ，Yamamoto Y ... -  《-》

Prevalence and characterization of Salmonella serovars in retail meats of marketplace in Shaanxi, China.

A total of 764 retail meat including 515 chicken, 91 pork, 78 beef and 80 lamb samples were collected in Shaanxi Province of China in 2007-2008 to determine the prevalence of Salmonella. The isolates were characterized using serotyping, antimicrobial susceptibility testing, and the presence of bla(CMY-2) and bla(TEM) and class I integrons. Selective serovars were further subtyped using PFGE. Approximately 54% (276) of chicken, 31% (28) of pork, 17% (13) of beef and 20% (16) of lamb samples were positive of Salmonella. Among 24 serovars identified, Enteritidis (31.5%) was most common, followed by Typhimurium (13.4%), Shubra (10.0%), Indiana (9.7%), Derby (9.5%) and Djugu (7.0%). Nearly 80% of the isolates (283) were resistant to at least one antimicrobial, and 53% (191) to more than three antimicrobials. Resistance was most frequently observed to sulfamethoxazole (67%), to trimethoprim/sulfamethoxazole (58%) and to tetracycline (56%). Furthermore, many isolates were resistant to nalidixic acid (35%), ciprofloxacin (21%) and ceftriaxone (16%). Most isolates of Shubra (89%) and Indiana (88%) were resistant to > or = 9 antimicrobials, compared to only 11% of Enteritidis and 9% of Infantis that showed similar resistance. Class I integrons were detected in 10% of the isolates, and contained aadA, tetR, dhfr, bla(PSE-1), bla(DHA-1) and bla(VEB-1) gene cassettes alone or various combinations. Ceftriaxone- and/or cefoperazone-resistant isolates (n=62) carried bla(TEM) (51.6%) and/or bla(CMY-2) (56.5%). A total of 116 PFGE patterns were generated among 210 selected isolates. Our findings indicated that Salmonella contamination was common in retail meats, and that the Salmonella isolates were phenotypically and genetically diverse. Additionally, many Salmonella isolates were resistant to multiple antimicrobials.

Yang B ，Qu D ，Zhang X ，Shen J ，Cui S ，Shi Y ，Xi M ，Sheng M ，Zhi S ，Meng J ... -  《-》