Ambulance vehicles as a source of multidrug-resistant infections: a multicenter study in Assiut City, Egypt

Abstract

Background: Ambulances may represent a potential source of infection to patients, patients' relatives, and paramedical staffs. In this study, we analyzed the extent of bacterial contamination in ambulance vehicles and measured the degree of antimicrobial resistance among isolated pathogens.

Materials and methods: Twenty-five vehicles were included and 16 sampling points were swabbed in each vehicle. Then the swabs were immediately transferred to the laboratory to identify bacterial contaminants utilizing standard microbiological procedures and API^® systems. Antibiotic susceptibility testing and screening for methicillin-resistant staphylococci and extended spectrum β-lactamases (ESBLs)-producing Gram-negative rods were carried out.

Results: A total of 400 samples were collected, 589 bacteria were isolated and 286 (48.6%) of the isolates were potentially pathogenic. The highest contamination rate with pathogenic bacteria was detected in suction devices (75.8%) and stethoscopes (67.7%). Staphylococci were the most frequently detected microorganisms (n=184) followed by Klebsiella spp. (49), Escherichia coli (40), Citrobacter spp. (7), and Proteus spp. (6). Staphylococci were mostly sensitive to vancomycin, whereas Gram-negative bacteria were sensitive to imipenem. Overall, 46.1% of Staphylococcus aureus were methicillin resistant, whereas 20.4% of the coagulase-negative staphylococci were methicillin resistant. Moreover, 36.7% of Klebsiella spp. and 27.5% of E. coli were ESBL producers.

Conclusion: Our study provides evidence that ambulances represent a source of prehospital multidrug-resistant infections.

Keywords: ambulance; contamination; extended spectrum β-lactamases; methicillin-resistant Staphylococcus aureus; resistance.

Figure 1

Frequency of methicillin-resistant staphylococci and ESBL-producing Klebsiella spp. and Escherichia coli in each site of ambulance vehicles. Note: When comparing the frequency of MRSA, MRCNS, and ESBLs among the different sites of vehicles, there were no pronounced trends in their distribution. However when taken together, portable ventilators and beds had higher counts, whereas DC shock apparatus and steering wheels had neither of them. Abbreviations: MRSA, methicillin-resistant Staphylococcus aureus; MRCNS, methicillin-resistant coagulase-negative staphylococci; ESBL, extended spectrum β-lactamase.