NontyphoidalSalmonellaInfection in Children with Acute Gastroenteritis: Prevalence, Serotypes, and Antimicrobial Resistance in Shanghai, China

Abstract

Information about nontyphoidal Salmonella (NTS) infection in children is limited in mainland China. The objective of this study was to investigate the prevalence, serotypes, and antibiotic resistance patterns of NTS infection in children in Shanghai. All cases with probable bacterial diarrhea were enrolled from the enteric clinic of a tertiary pediatric hospital between July 2010 and December 2011. Salmonella isolation, serotyping, and antimicrobial susceptibility testing were conducted by the microbiological laboratory. NTS were recovered from 316 (17.2%) of 1833 cases with isolation rate exceeding Campylobacter (7.1%) and Shigella (5.7%). NTS infection was prevalent year-round with a seasonal peak during summer and autumn. The median age of children with NTS gastroenteritis was 18 months. Fever and blood-in-stool were reported in 52.5% and 42.7% of cases, respectively. Salmonella Enteritidis (38.9%) and Salmonella Typhimurium (29.7%) were the most common serovars. Antimicrobial susceptibility showed 60.5% of isolates resistant to ≥1 clinically important antibiotics. Resistance to ciprofloxacin and the third-generation cephalosporins was detected in 5.5% and 7.1%-11.7% of isolates, respectively. NTS is a major enteropathogen responsible for bacterial gastroenteritis in children in Shanghai. Resistance to the current first-line antibiotics is of concern. Ongoing surveillance for NTS infection and antibiotic resistance is needed to control this pathogen in Shanghai.

Prevalence, resistance, and extended-spectrum beta-lactamases among Salmonella from patients in northeast China

“…SGI1 carries resistance genes blaPSE-1, floR, aadA, sul, and tet encoding the resistance feature to ampicillin, chloramphenicol, streptomycin, sulfonamide, and tetracycline, respectively (phenotype ACSSuT) [44]. In our study, the prevalence of ACSSuT in 1,4, [5],12:i:-, S. Typhimurium, and S. Choleraesuis was significantly higher than in S. Enteritidis; this is similar to findings in Shanghai [9]. Data from Switzerland [40] Statistical analysis of ≥ 3 clinically important antimicrobial agents showed that S. Choleraesuis was the most resistant Salmonella isolate, and that extended-spectrum cephalosporin is the best drug to treat Salmonella infections.…”

“…S. Enteritidis is the most frequently isolated Salmonella serotype in our local area, so we should pay attention to its features. The 9% rate of resistance to ceftriaxone in this study was higher compared to < 1% in Spain in 2007-2009 [28], similar to data from Shanghai [9], and lower compared to the 50%-60% E. coli rates in the local area [29]. It is different from Europe and America where TEM and SHV is the main type of ESBL; CTX-M is prevalent in Asia, generally.…”

“…The rate of resistance to ciprofloxacin in our study (23%) was significantly higher compared to Shanghai (5.5%) [9], but might be correlated with the ciprofloxacin modification breakpoint. Because the high intermediate rate differs for other bacteria, the investigation of non-susceptibility rates to ciprofloxacin and levofloxacin can be regarded with practical significance.…”

“…For example, the extendedspectrum β-lactamase (ESBL) genes cause resistance to third-and fourth-generation cephalosporins in Enterobacteriaceae; TEM and SHV are found frequently in Europe [7], but CTX-M is the most prevalent in Asia [8]. In recent years, Salmonella has been studied extensively worldwide, but relevant studies of the isolation from humans in China were restricted to Shanghai [9], Jiangxi [10,11] and Henan [12] in the south.…”

Antimicrobial resistance: a global multifaceted phenomenon

“…Multidrug resistance has been associated with a higher risk of invasive infection, higher frequency and duration of hospitalisation and increased risk of death as compared to infections caused by susceptible strains. 40,41 In addition, from 2000, several studies have shown a decreased susceptibility to fluoroquinolones, drugs of choice for treatment of invasive gastrointestinal infections, in many parts of the world. [42][43][44] According to data reported by WHO, fluoroquinolone resistance in NTS is lower in the European region, while it is much higher in some countries of Africa (30%-35%), of Eastern Mediterranean region (46%-49%) and in Peru (96%).…”