A total of 133 Salmonella isolates recovered from retail meats purchased in the United States and the People's Republic of China were assayed for antimicrobial susceptibility, the presence of integrons and antimicrobial resistance genes, and horizontal transfer of characterized antimicrobial resistance determinants via conjugation. Seventy-three (82%) of these Salmonella isolates were resistant to at least one antimicrobial agent. Resistance to the following antibiotics was common among the United States isolates: tetracycline (68% of the isolates were resistant), streptomycin (61%), sulfamethoxazole (42%), and ampicillin (29%). Eight Salmonella isolates (6%) were resistant to ceftriaxone. Fourteen isolates (11%) from the People's Republic of China were resistant to nalidixic acid and displayed decreased susceptibility to ciprofloxacin. A total of 19 different antimicrobial resistance genes were identified in 30 multidrug-resistant Salmonella isolates. The bla CMY-2 gene, encoding a class A AmpC ␤-lactamase, was detected in all 10 Salmonella isolates resistant to extended-spectrum ␤-lactams. Resistance to ampicillin was most often associated with a TEM-1 family ␤-lactamase gene. Six aminoglycoside resistance genes, aadA1, aadA2, aacC2, Kn, aph(3)-IIa, and aac(3)-IVa, were commonly present in the Salmonella isolates. Sixteen (54%) of 30 Salmonella isolates tested had integrons ranging in size from 0.75 to 2.7 kb. Conjugation studies demonstrated that there was plasmid-mediated transfer of genes encoding CMY-2 and TEM-1-like ␤-lactamases. These data indicate that Salmonella isolates recovered from retail raw meats are commonly resistant to multiple antimicrobials, including those used for treating salmonellosis, such as ceftriaxone. Genes conferring antimicrobial resistance in Salmonella are often carried on integrons and plasmids and could be transmitted through conjugation. These mobile DNA elements have likely played an important role in transmission and dissemination of antimicrobial resistance determinants among Salmonella strains.

MRSA from Chinese pigs and farm workers (ST9) differed from the European pig-associated clone (ST398) with regard to clonal type, SCCmec content and resistance profile.

Summary Objectives Diarrhea is a leading cause of morbidity and mortality for children, although sparse data is available on the etiology of diarrhea in China. This study was conducted to determine main causes that underlie childhood diarrhea and related diseases. Method Surveillance data for diarrhea was collected from 213 participating hospitals between 2009 and 2013. These stool specimens, from children aged 0e59 months, were then analyzed for a panel of etiological agents consisting of 5 viruses, 8 bacteria and 3 protozoa. The proportion of children who tested positive for each pathogen was calculated and seasonal patterns for major organisms were determined. Results Pathogens were identified in 44.6% of the 32,189 samples from children with diarrhea. The most commonly detected pathogens were rotavirus (29.7% of cases), norovirus (11.8%), Diarrheagenic Escherichia coli (DEC; 5.0%), adenovirus (4.8%), non-typhoidal Salmonella (NTS; 4.3%), and Shigella spp. (3.6%). A strong seasonal pattern was observed for these organisms, including rotavirus (winter), norovirus (autumn), and DEC, NTS, and Shigella (summer). Conclusion: A wide range of enteropathogens were detected in this five-year surveillance study; rotavirus and norovirus were most common among children under the age five. These findings should serve as robust evidence for public health entities when planning and developing national intervention programs in China.

We characterized 208 human Salmonella isolates from 2006 to 2007 and 27 human Salmonella enterica serovar Typhimurium isolates from 1987 to 1993 from Henan Province, China, by serotyping, by antimicrobial susceptibility testing, and, for the most common serovars, by pulsed-field gel electrophoresis (PFGE). The most common serovars among the 2006-2007 isolates were S. enterica serovar Typhimurium (27%), S. enterica serovar Enteritidis (17%), S. enterica serovar Derby (10%), S. enterica serovar Indiana (6%), and S. enterica serovar Litchfield (6%). A high percentage of the isolates were multiple-drug resistant, and 54% were resistant to both nalidixic acid and ciprofloxacin. Of these, 42% were resistant to a high level of ciprofloxacin (MIC > 4 g/ml), whereas for the remaining isolates, the MICs ranged from 0.125 to 2 g/ml. Five isolates (2%) were ceftiofur resistant and harbored bla CTX-M14 or bla CTX-M15 . With the possible exception of the quinolones and cephalosporins, the 1987-1993 S. enterica serovar Typhimurium isolates were almost as resistant as the recent isolates. PFGE typing of S. enterica serovar Typhimurium showed that the most common cluster predominated over time. Two other clusters have emerged, and another cluster has disappeared.

BackgroundNon-typhoidal Salmonella is a common cause of infectious diarrhea in humans. Antimicrobial-resistant Salmonella has become a global concern.MethodsUsing laboratory-based surveillance system for Salmonella from September 2009 to December 2012 in Guangdong Province of China. The clinical information and samples of diarrhea patients were collected, according to the surveillance case definition. The lab tests were followed by standardized protocols, including sample isolation, isolates confirmation, serotyping, and antimicrobial susceptibility testing (AST).ResultsA total of 1,826 Salmonella isolates were identified from40,572 patients in 28 hospitals in11 prefectures. The isolates ratio was highest in autumn (38.8%, 708/1826) and lowest in winter (6.4%, 117/1826). Children aged <5 years were the group most affected by Salmonella in Guangdong Province accounting for 73% (1,329/1,826), of whom the infants (<1 year) were 81.5% (1084/1329) especially. A total of 108 serotypes were identified among the isolates. S. Typhimurium represented the most common serotype followed by serotype 4,5,12:i:-.S. Typhimurium was also the common serotype followed by S. Enteritidis among infants and children aged 1-3 years old. However, S. Enteritidis became the common serotype followed by S. Typhimurium among children aged 3–5 and >5 years.Resistance to at least one antimicrobial was found in 72% (1321/1,826) of the isolates. Resistance to at least three antimicrobials was found in 46% (850/1,826) of the isolates. Resistance to all 12 antimicrobials screened was observed in 8 isolates (0.44%, 8/1,826). The resistant prevalence to quinolones including nalidixic acid and ciprofloxacin was 61.9% (1131/1826), of which ciprofloxacin resistance rate was 8.05% (147/1826). The prevalence resistance to all three cephalosporin antimicrobials (cefepime, cefotaxime, and caftazidime) in <5 yr age group was accounted for 90% (89/99).ConclusionsAdditional data and more refined methods can improve future surveillance. The invasive Salmonella isolates should also be included to the antibiotic resistance surveillance for clinical care or public health.

Foodborne infections are an important public health problem in China. In 2008, we conducted surveillance for laboratory-confirmed nontyphoidal Salmonella to monitor trends for this infection in China and to build capacity for rapid detection and response to foodborne outbreaks. Salmonella isolates from patients with diarrhea were sent from hospitals to local public health laboratories for confirmation, serotyping, and antimicrobial susceptibility testing. A total of 126 hospitals in 44 cities and counties from 8 provinces provided isolates and epidemiologic data for analysis. Of 23,140 stool specimens submitted to clinical laboratories, 662 (3%) grew Salmonella enterica. Salmonella were most commonly detected between April and October. The median age of infected patients was 27 years; 34% of infections occurred in patients <5 years old. Of the 662 isolates, we found 73 serotypes, of which serotype Enteritidis (31%) and serotype Typhimurium (26%) were the most common. The prevalence of resistance was high for clinically important antimicrobial agents, including ampicillin (41%) and ciprofloxacin (6%). More than 60% of isolates, including 35% of all Typhimurium, were resistant to three or more antimicrobial agents. In this first multiprovince surveillance report of laboratory-confirmed Salmonella infections in China, we found that Enteritidis and Typhimurium are the most common serotypes and that efforts to reduce antimicrobial resistance among Salmonella in China are needed. Although no outbreaks were detected using this system, efforts to improve this system's capacity to do so are underway.

ESBL-producing or fluoroquinolone-resistant Shigella is no longer an unusual phenomenon in the local community. The monitoring programme in China should stay vigilant to the dissemination of these isolates and the health agencies must take appropriate measures to restrict the abuse of antimicrobials, especially in the community.

Based on these results, fluoroquinolones should not be used to treat the invasive Salmonella Typhimurium infections in this local community. The monitoring programme should stay vigilant for ceftriaxone-resistant S. enterica isolates with reduced fluoroquinolone susceptibility.