Antimicrobial resistance of bacterial isolates from respiratory care wards in Taiwan: a horizontal surveillance study

A horizontal surveillance study was conducted to identify common bacteria and mycobacteria from 611 respiratory aspirates and 165 urinary samples from 611 patients hospitalised at 17 respiratory care wards (RCWs) in Taiwan. Some major resistance phenotypes, including methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis, and multidrug-resistant Pseudomonas aeruginosa (MDR-PA) and Acinetobacter baumannii (MDR-AB), were identified. Pulsotypes of ESBL-producing P. mirabilis isolates were determined by pulsed-field gel electrophoresis. The prevalences of MRSA, ESBL-producing E. coli (K. pneumoniae and P. mirabilis), carbapenem-resistant (resistant to imipenem and meropenem) P. aeruginosa, MDR-PA, carbapenem-resistant A. baumannii and MDR-AB were, respectively, 86.7%, 20.0% (50.7% and 24.1%), 18.4%, 1.2%, 32.1% and 8.9% for respiratory aspirates and 100%, 25.4% (27.3% and 25.0%), 48.3%, 10.3%, 50.0% and 21.4% for catheterised urinary samples. Among the 44 respiratory isolates of P. mirabilis with an ESBL phenotype, 22 different pulsotypes (>80% identity) were identified. Among 103 isolates of mycobacteria, 90 (87.4%) belonged to rapidly growing mycobacteria and 4 (4%) were Mycobacterium tuberculosis. Among the 404 patients with available clinical information, true infections were found in 28.0%, the most prevalent of which were urinary tract infection (20.5%) and ventilator-associated pneumonia (10.9%). High prevalences of various multidrug-resistant bacteria among the respiratory and urinary tracts of patients present a clinical difficulty in choosing empirical antibiotic treatment in RCWs.