Bacterial-resistance among outpatients of county hospitals in China: significant geographic distinctions and minor differences between central cities.

The purpose of this study was to survey antibacterial resistance in outpatients of Chinese county hospitals. A total of 31 county hospitals were selected and samples continuously collected from August 2010 to August 2011. Drug sensitivity testing was conducted in a central laboratory. A total of 2946 unique isolates were collected, including 634 strains of Escherichia coli, 606 Klebsiella pneumoniae, 476 Staphylococcus aureus, 308 Streptococcus pneumoniae, and 160 Haemophilus influenzae. Extended-spectrum β-lactamases were detected in E. coli (42.3% strains), K. pneumoniae (31.7%), and Proteus mirabilis (39.0%). Ciprofloxacin-resistance was detected in 51.0% of E. coli strains. Salmonella spp. and Shigella spp. were sensitive to most antibacterial agents. Less than 8.0% of Pseudomonas aeruginosa isolates were resistant to carbapenem. For S. aureus strains, 15.3% were resistant to methicillin, and some strains of S. pneumoniae showed resistance to penicillin (1.6%), ceftriaxone (13.0%), and erythromycin (96.4%). β-lactamase was produced by 96.5% of Moraxella catarrhalis strains, and 36.2% of H. influenzae isolates were resistant to ampicillin. Azithromycin-resistant H. influenzae, imipenem-resistant but meropenem-sensitive Proteus, and ceftriaxone- and carbapenem non-sensitive M. catarrhalis were recorded. In conclusion, cephalosporin- and quinolone-resistant strains of E. coli and Klebsiella pneumonia and macrolide-resistant Gram-positive cocci were relatively prominent in county hospitals. The antibacterial resistance profiles of isolates from different geographical locations varied significantly, with proportions in county hospitals lower than those in their tertiary counterparts in the central cities, although the difference is diminishing.