Antimicrobial resistance acquisition after international travel in U.S. travelers.

Dana M Blyth,Wendy C Zera,Kevin S Akers,Clinton K Murray,Miriam L Beckius,Katrin Mende,Crystal A Rosemann,Ashley M Maranich,Kristie A Harnisch

doi:10.1186/s40794-016-0020-2

Abstract

BackgroundPrior studies have shown an increase in multidrug-resistant (MDR) E. coli colonization from two percent in U.S.-based to 11 % in deployed, healthy military personnel. It is unclear if colonization with MDR organisms occurs through deployment exposures or risks related to routine overseas travel. This study prospectively evaluates rates and risk factors associated with MDR gram-negative bacterial and methicillin-resistant S. aureus (MRSA) colonization after international travel.MethodsParticipants traveled internationally for five or more days. Pre- and post-travel, colonizing bacteria from oropharyngeal, nares, groin, and peri-rectal (PR) areas were collected using BD CultureSwab™ MaxV(+). Identification and susceptibilities were done utilizing the BD Phoenix™ Automated Microbiology System. Non-MDR pre- and post-travel MDR bacteria within a subject were compared by pulsed-field gel electrophoresis (PFGE). A questionnaire solicited demographics and potential risk factors for MDR acquisition.ResultsOf 58 participants, 41 % were male and median age was 64 years. Pre- and post-travel swabs were obtained a median of ten and seven days before and after travel, respectively. Itineraries included 18 participants traveling to the Caribbean and Central America, 17 to Asia, 16 to Africa, 5 to Europe, 4 to South and North America. Seventeen of 22 travelers used atovaquone/proguanil for malaria prophylaxis. The only MDR organism isolated was extended-spectrum β-lactamase (ESBL)-producing E. coli in five (9 %) participants post-travel (all PR and unrelated by PFGE). There were no statistically significant associations between exposure risks and new ESBL-producing E.coli colonization. Of 36 participants colonized with E. coli pre- and post-travel, new resistance was detected: TMP/SMX in 42 % of isolates (p < 0.01), tetracycline in 44 % (p < 0.01), and ampicillin-sulbactam in 33 % (p = 0.09). No participants were colonized with MRSA pre- or post-travel.ConclusionConsistent with prior studies, new antimicrobial resistance was noted in colonizing E. coli after international travel. Nine percent of participants acquired new strains of ESBL-producing E.coli without identified risks.

Highlights

Prior studies have shown an increase in multidrug-resistant (MDR) E. coli colonization from two percent in U.S.-based to 11 % in deployed, healthy military personnel
S. aureus bacterial colonization pre- and post-travel No participants were colonized with methicillin-resistant S. aureus (MRSA) pre- or post-travel (Table 4)
To further elucidate the risk factors associated with preinjury colonization with MDR gram-negative organisms in our deployed population, we first sought to evaluate the risk factors associated with MDR organism colonization in international travelers

Summary

Introduction

Prior studies have shown an increase in multidrug-resistant (MDR) E. coli colonization from two percent in U.S.-based to 11 % in deployed, healthy military personnel. It is unclear if colonization with MDR organisms occurs through deployment exposures or risks related to routine overseas travel. MDR organism pre- and post-travel colonization within a population of international travelers based out of San Antonio Military Medical Center (SAMMC). The objective of this pilot study was to prospectively assess antimicrobial resistance patterns and associated risk factors in bacterial colonization before and after international travel in a U.S cohort

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Results

Discussion

Conclusion