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Rectal carriage of antimicrobial resistant Enterobacteriaceae among MSM using HIV pre-exposure prophylaxis (PrEP): A
Leonardo Calza1,2, Marielle Ezekielle Djusse3, Claudio Foschi3,4
1Section of Infectious Diseases, Department of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy.
Abstract:
BackgroundMen who have sex with men (MSM) receiving HIV pre-exposure prophylaxis (PrEP) are often exposed to repeated antimicrobials due to a high burden of sexually transmitted infections (STIs). These factors may contribute to the selection of antimicrobial resistant bacteria within the intestinal microbiota. This study aimed to investigate the prevalence of antimicrobial resistance (AMR) among Enterobacteriaceae isolated from rectal swabs of MSM receiving PrEP and to assess possible associations with behavioral and PrEP-related variables.MethodsIn this cross-sectional study, rectal swabs were collected from MSM receiving PrEP who had no gastrointestinal symptoms and were attending the Infectious Diseases Clinic of the 'IRCCS Azienda Ospedaliero-Universitaria di Bologna' (Italy) for routine STI screening. The same anorectal specimens were used for culture-based isolation, and antimicrobial susceptibility testing of Enterobacteriaceae. Behavioral and clinical data were collected through structured questionnaires.ResultsA total of 126 Enterobacteriaceae isolates, predominantly Escherichia coli (n = 79; 63%) and Klebsiella spp. (n = 35; 28%), were recovered from 89 of the 92 subjects enrolled. Nearly three-quarters of participants reported antimicrobial use in the previous 12 months, and almost one quarter in the month preceding enrolment. Overall, 40% and 39% of participants reported Chlamydia trachomatis and Neisseria gonorrhoeae, respectively, within the previous two years. Considering all Enterobacteriaceae isolates, resistance to sulfamethoxazole/trimethoprim was the most frequent, followed by ciprofloxacin; resistance to third-generation cephalosporins ranged from 5% to 8%. Resistance to piperacillin/tazobactam was rare (2%), and no carbapenem-resistant isolates were detected. Although not statistically significant, participants reporting recent antibiotic use were more likely to harbor resistant strains across all antimicrobial classes.ConclusionsRepeated antimicrobial exposure for STI management may shape intestinal resistance patterns of Enterobacteriaceae among MSM receiving PrEP. Our findings support the need for continued AMR monitoring and targeted antimicrobial stewardship interventions in this population.
Insights
Antimicrobial resistance (AMR) is common in Enterobacteriaceae from men who have sex with men (MSM) on HIV pre-exposure prophylaxis (PrEP). Repeated antibiotic use for sexually transmitted infections (STIs) may drive this resistance, highlighting the need for monitoring and stewardship.
Area of Science:
- Microbiology
- Infectious Diseases
- Public Health
Background:
- Men who have sex with men (MSM) on HIV pre-exposure prophylaxis (PrEP) often receive repeated antimicrobial treatments for sexually transmitted infections (STIs).
- This frequent antimicrobial exposure may promote the development of antimicrobial resistance (AMR) in the gut microbiota.
- Investigating AMR prevalence in Enterobacteriaceae among this population is crucial.
Purpose of the Study:
- To determine the prevalence of antimicrobial resistance (AMR) in Enterobacteriaceae isolated from rectal swabs of MSM receiving PrEP.
- To explore potential links between AMR and behavioral or PrEP-related factors in this cohort.
Main Methods:
- Cross-sectional study involving rectal swab collection from MSM on PrEP attending routine STI screening.
- Culture-based isolation and antimicrobial susceptibility testing of Enterobacteriaceae.
- Data collection on participant behavior and clinical history via questionnaires.
Main Results:
- 126 Enterobacteriaceae isolates (primarily Escherichia coli and Klebsiella spp.) were recovered from 92 participants.
- High rates of recent antimicrobial use (75% in 12 months, 25% in 1 month) and STI prevalence (Chlamydia trachomatis 40%, Neisseria gonorrhoeae 39%) were reported.
- Sulfamethoxazole/trimethoprim and ciprofloxacin resistance were most common; third-generation cephalosporin resistance was 5-8%. No carbapenem resistance was detected.
Conclusions:
- Repeated antimicrobial exposure associated with STI management may influence intestinal Enterobacteriaceae resistance patterns in MSM on PrEP.
- Findings underscore the necessity for ongoing AMR surveillance.
- Targeted antimicrobial stewardship interventions are recommended for this population.
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