Distribution and antimicrobial resistance of enteric pathogens in Chinese paediatric diarrhoea: a multicentre retrospective study, 2008-2013

Abstract

The enteric pathogens causing diarrhoea impair children's health severely. This study retrospectively analysed 1577 pathogens isolated from inpatients and outpatients in six hospitals located in Northern (Inner Mongolia), Northeastern (Hebei), Eastern (Shanghai and Jiangsu), Southern (Hainan) and Central (Hubei) China between 2008 and 2013. Of the 1577 enteric pathogens, Salmonella presented with the highest frequency (36·0%), followed by diarrhoeagenic Escherichia coli (23·7%), Staphylococcus aureus (15·0%), Shigella (13·1%), and Aeromonas (4·6%). The predominant pathogens varied in different regions of China, with Salmonella most prevalent in Shanghai and Hainan, diarrhoeagenic E. coli most prevalent in Inner Mongolia, Jiangsu and Hubei, and Shigella most prevalent in Hebei. Enteric pathogens were more frequently isolated in males (56·9%) than in females (43·1%). The highest proportion of all enteric pathogens was found in infants (67·6%) with a peak in summer and autumn (68·5%). Antimicrobial susceptibility assay demonstrated that Shigella was more resistant to ampicillin, ceftriaxone and sulfamethoxazole than Salmonella. Of the top two serotypes in Salmonella, Typhimurium was more resistant to ciprofloxacin, sulfamethoxazole and chloramphenicol than Enteritidis (P < 0·001). Meanwhile, the resistance rates of Shigella flexneri against ampicillin/sulbactam, ciprofloxacin, and chloramphenicol were significantly higher than those of Shigella sonnei (P < 0·001). Multidrug resistance was apparent in 58·2% of Shigella and 45·9% of Salmonella, and this phenomenon was more pronounced in S. flexneri.

Keywords: Antibiotic resistance; Salmonella; Shigella; bacteriology; diarrhoea.

Fig. 1.

Proportion of enteric pathogens isolated from different regions in China. During 2008–2013 a total of 1577 strains were isolated from three tier 3 (tertiary) hospitals (Shanghai Children's Hospital, Inner Mongolia Maternal and Children's Hospital, and Hubei Provincial Maternal and Children's Hospital); two tier 2 (municipal) hospitals (Shijiazhuang Municipal Obstetric and Maternal Hospital and Lianyungang Municipal Maternal and Children's Hospital). The total number of bacteria isolated in Hainan province presented includes all hospitals in Hainan province (data collected from the Hainan provincial surveillance system). The percentage in this figure shows the relative portion of each individual enteric pathogen isolated.

Fig. 2.

Enteric pathogens isolated between 2008 and 2013 in China. An interesting trend has been shown for Salmonella and Shigella: Salmonella increased from 29% in 2008 (and 27% in 2009) up to about 50% in 2013. However, Shigella decreased from 33% in 2008 down to 3%.