Epidemiology of extended-spectrum β-lactamase producing Escherichia coli in the stools of returning Japanese travelers, and the risk factors for colonization

Colonization with extended-spectrum beta-lactamase-producing Escherichia coli and traveler's diarrhea attack rates among travelers to India: a systematic review and meta-analysis

Background

India is an attractive destination for travelers. Unfortunately, numerous reports exist on traveler’s diarrhea (TD) and fecal colonization with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) among international travelers visiting India. Here, we systematically reviewed studies published on the acquisition of ESBL-EC and TD attack rates among international visitors to India.

Methods

Design: Systematic review and meta-analysis.

A systematic search was performed using Google Scholar, PubMed, EMBASE, Web of Science, and gray literature from 2000 to December 2021, for studies containing data for ESBL-EC acquisition or TD experience related to a trip to India. Random effects models were used to compute the prevalence of ESBL-EC acquisition and TD attack.

Results

The literature search yielded a total of 5023 records. Of these, 31 met our inclusion criteria for systematic review and only 17 could be meta-analyzed (9 for TD, and 8 for ESBL-EC). The overall pooled attack rate of TD was 39% (95% confidence interval, CI: 25–53%). In studies where travelers' memory was used to diagnose TD, the pooled attack rate of TD was slightly higher (42%, 95% CI: 21–64%) compared to those where TD was objectively documented (33%, 95% CI: 17–49%). There were significant risks to be colonized with ESBL-EC among the travelers who experienced TD. The pooled rate of ESBL-EC colonization was 72% (CI: 67–78%). Most ESBL-EC produced CTX-M-15 enzyme. Furthermore, most of the travelers who acquired ESBL-EC were from highly industrialized countries recruited from travel clinics: Canada (n = 80), Germany (n = 69), Netherlands (n = 20), Sweden (n = 18), Japan (n = 10), Finland (n = 8), USA (n = 7), Spain (n = 5), and Denmark (n = 3).

Conclusions

TD pooled attack rate and ESBL-EC acquisition among international travelers visiting India were high in this study. However, we cannot make generalizations based upon this TD pooled attack rate for the current situation, due to a lack of current data. Our study highlights that travelers should be advised on TD to ensure that they do not disregard the risk of contracting TD and be better prepared as a result. It also illustrates the importance of international travel in acquiring antibiotic-resistant Escherichia coli.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40794-022-00179-1.

Transmission routes of antibiotic resistant bacteria: a systematic review

Background

Quantification of acquisition routes of antibiotic resistant bacteria (ARB) is pivotal for understanding transmission dynamics and designing cost-effective interventions. Different methods have been used to quantify the importance of transmission routes, such as relative risks, odds ratios (OR), genomic comparisons and basic reproduction numbers. We systematically reviewed reported estimates on acquisition routes’ contributions of ARB in humans, animals, water and the environment and assessed the methods used to quantify the importance of transmission routes.

Methods

PubMed and EMBASE were searched, resulting in 6054 articles published up until January 1st, 2019. Full text screening was performed on 525 articles and 277 are included.

Results

We extracted 718 estimates with S. aureus (n = 273), E. coli (n = 157) and Enterobacteriaceae (n = 99) being studied most frequently. Most estimates were derived from statistical methods (n = 560), mainly expressed as risks (n = 246) and ORs (n = 239), followed by genetic comparisons (n = 85), modelling (n = 62) and dosage of ARB ingested (n = 17). Transmission routes analysed most frequently were occupational exposure (n = 157), travelling (n = 110) and contacts with carriers (n = 83). Studies were mostly performed in the United States (n = 142), the Netherlands (n = 87) and Germany (n = 60). Comparison of methods was not possible as studies using different methods to estimate the same route were lacking. Due to study heterogeneity not all estimates by the same method could be pooled.

Conclusion

Despite an abundance of published data the relative importance of transmission routes of ARB has not been accurately quantified. Links between exposure and acquisition are often present, but the frequency of exposure is missing, which disables estimation of transmission routes’ importance. To create effective policies reducing ARB, estimates of transmission should be weighed by the frequency of exposure occurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07360-z.

Role of gut microbiota in travel-related acquisition of extended spectrum β-lactamase-producing Enterobacteriaceae

BACKGROUND

International travel could facilitate the spread of antimicrobial-resistant bacteria including extended spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E). Previous studies, which attempted to understand the role of gut microbiota in the acquisition of antimicrobial resistant bacteria during international travels, are limited to western travellers.

METHODS

We established a prospective cohort of 90 Hong Kong travellers to investigate gut microbiota determinants and associated risk factors for the acquisition of ESBL-E. Baseline characteristics and travel-associated risk factors were gathered through questionnaires. Faecal samples were collected in 3-4 days before and after travel. Antimicrobial susceptibility of ESBL-E isolates was tested, and gut microbiota were profiled by 16S rDNA amplicon sequencing. Non-parametric tests were used to detect potential associations, and logistic regression models were used to quantify the associations. Random forest models were constructed to identify microbial predictors for ESBL-E acquisition.

RESULTS

In total, 49 (54.4%) participants were tested negative for ESBL-E colonization before travel and were followed up after travel. A total of 60 ESBL-E isolates were cultured from 20 (40.8%) participants. Having low Actinobacteria richness and low abundance of short-chain fatty acid-producing bacteria in the gut microbiota before travel increased the risk of acquiring ESBL-E and the risk can be further exacerbated by eating raw seafood during travel. Besides, post-travel ESBL-E positive participants had increased abundances of several opportunistic pathogens such as Staphylococcus, Enterococcus, Escherichia/Shigella and Klebsiella. The random forest model integrating pre-travel microbiota and the identified travel-related risk factor could predict ESBL-E acquisition with an area under the curve of 75.4% (95% confidence interval: 57.9-93.0%).

CONCLUSIONS

In this study, we identified both travel-related risk factors and microbiota predictors for the risk of ESBL-E acquisition. Our results provide foundational knowledge for future developments of microbiota-based interventions to prevent ESBL-E acquisition during international travels.

Travel-Related Antimicrobial Resistance: A Systematic Review

There is increasing evidence that human movement facilitates the global spread of resistant bacteria and antimicrobial resistance (AMR) genes. We systematically reviewed the literature on the impact of travel on the dissemination of AMR. We searched the databases Medline, EMBASE and SCOPUS from database inception until the end of June 2019. Of the 3052 titles identified, 2253 articles passed the initial screening, of which 238 met the inclusion criteria. The studies covered 30,060 drug-resistant isolates from 26 identified bacterial species. Most were enteric, accounting for 65% of the identified species and 92% of all documented isolates. High-income countries were more likely to be recipient nations for AMR originating from middle- and low-income countries. The most common origin of travellers with resistant bacteria was Asia, covering 36% of the total isolates. Beta-lactams and quinolones were the most documented drug-resistant organisms, accounting for 35% and 31% of the overall drug resistance, respectively. Medical tourism was twice as likely to be associated with multidrug-resistant organisms than general travel. International travel is a vehicle for the transmission of antimicrobial resistance globally. Health systems should identify recent travellers to ensure that adequate precautions are taken.

Traveler's diarrhea in Nepal-changes in etiology and antimicrobial resistance

BACKGROUND

We conducted a comprehensive investigation to update our knowledge of traveler's diarrhea (TD) etiology and antimicrobial resistance (AMR) in Nepal.

METHODS

A case-control study of TD etiology was conducted at the CIWEC Clinic Travel Medicine Center in Kathmandu from 2012 to 2014. Stool samples were tested by microscopy, culture and molecular techniques for identification of bacterial, viral and parasitic enteric pathogens, and AMR. We analysed patient demographic data, pre-treatment information and clinical outcomes.

RESULTS

We enrolled 433 TD cases and 209 non-diarrhea controls. At least one of enteric pathogens was identified among 82% of cases and 44% of controls (P < 0.001). Multiple pathogens were observed among 35% of cases and 10% of controls. The most common pathogens significantly identified among cases in comparison with controls were Campylobacter (20%), norovirus (17%), enterotoxigenic E. coli (ETEC) (12%), rotavirus (9%) and Shigella (8%) (P < 0.001). We noted Campylobacter, Shigella and ETEC resistance to azithromycin at 8, 39 and 22% and to ciprofloxacin at 97, 78 and 23%, respectively.

CONCLUSION

Among travellers to Nepal with TD, viral pathogens were commonly found and norovirus was the second most common pathogen after campylobacter. We noted increased AMR to fluoroquinolones (FQs) and azithromycin (AZM). There is heightened concern for AZM treatment failures, though this continues to remain the drug of choice for TD treatment in our setting where FQs should not be used.

Global Extraintestinal Pathogenic Escherichia coli (ExPEC) Lineages

Extraintestinal pathogenic Escherichia coli (ExPEC) strains are responsible for a majority of human extraintestinal infections globally, resulting in enormous direct medical and social costs. ExPEC strains are comprised of many lineages, but only a subset is responsible for the vast majority of infections. Few systematic surveillance systems exist for ExPEC. To address this gap, we systematically reviewed and meta-analyzed 217 studies (1995 to 2018) that performed multilocus sequence typing or whole-genome sequencing to genotype E. coli recovered from extraintestinal infections or the gut. Twenty major ExPEC sequence types (STs) accounted for 85% of E. coli isolates from the included studies. ST131 was the most common ST from 2000 onwards, covering all geographic regions. Antimicrobial resistance-based isolate study inclusion criteria likely led to an overestimation and underestimation of some lineages. European and North American studies showed similar distributions of ExPEC STs, but Asian and African studies diverged. Epidemiology and population dynamics of ExPEC are complex; summary proportion for some STs varied over time (e.g., ST95), while other STs were constant (e.g., ST10). Persistence, adaptation, and predominance in the intestinal reservoir may drive ExPEC success. Systematic, unbiased tracking of predominant ExPEC lineages will direct research toward better treatment and prevention strategies for extraintestinal infections.

Emergence of Resistance to Quinolones and β-Lactam Antibiotics in Enteroaggregative and Enterotoxigenic Escherichia coli Causing Traveler's Diarrhea

The objective of this study was to assess the antimicrobial resistance of enteroaggregative Escherichia coli (EAEC) and enterotoxigenic E. coli (ETEC) strains causing traveler's diarrhea (TD) and to investigate the molecular characterization of antimicrobial resistance genes to third-generation cephalosporins, cephamycins, and quinolones. Overall, 39 EAEC and 43 ETEC clinical isolates were studied. The susceptibilities of EAEC and ETEC against ampicillin, amoxicillin-clavulanic acid, cefotaxime, imipenem, chloramphenicol, tetracycline, co-trimoxazole, nalidixic acid, ciprofloxacin, azithromycin, and rifaximin were determined. All genes encoding resistance determinants were detected by PCR or PCR plus DNA sequencing. The epidemiology of selected EAEC and ETEC strains was studied using multilocus sequence typing (MLST). The resistance to quinolones of EAEC and ETEC strains causing TD has significantly increased over the last decades, and high percentages have been found especially in patients traveling to India and sub-Saharan Africa. Sequence type 38 (ST38) and ST131, carrying the bla _CTX-M-15 and bla _CTX-M-27 genes, respectively, are highly prevalent among extended-spectrum β-lactamase (ESBL)-producing EAEC and ETEC strains. The cephamycinase ACT-20 is described in the present study for the first time in EAEC and ETEC strains causing TD in patients who had traveled to Central America. The percentages of resistance to azithromycin in EAEC and ETEC isolates from patients to Southeast Asia/India and Africa are above 25%. Meanwhile, rifaximin is still active against EAEC and ETEC, with the prevalence of resistant strains not being high. In conclusion, fluoroquinolones should no longer be considered the drugs of choice for the prevention or treatment in TD for travelers traveling to India and Africa. Azithromycin and rifaximin are still a good alternative to treat TD caused by EAEC or ETEC.

Prevalence and risk factors for Extended-Spectrum Beta-Lactamase-producing- Enterobacteriaceae in French military and civilian travelers: A cross-sectional analysis

BACKGROUND

International travel is a risk factor for colonization with Extended-Spectrum Beta-Lactamase-producing- Enterobacteriaceae (ESBL-E). We describe the prevalence of and risk-factors for ESBL-E colonization in civilian and military travelers.

METHODS

Patients hospitalized in the infectious diseases department of Bégin Military Hospital (France) from May 2012 to November 2015, who had traveled abroad over the past two months, were screened for intestinal colonization with ESBL-E.

RESULTS

Forty-one out of 166 travelers (24.7%) had ESBL-E colonization, predominantly Escherichia coli. The risk factors for ESBL-E colonization in the univariate analysis were a treatment with any antibiotic in the last two months (OR 4.19, 95% CI 1.91-9.16) or with a beta-lactam in the same period (OR 3.35, 95% CI 1.44-7.82), and an hospitalization in the last two months (OR 3.96, 95% CI 1.91-9.16). The military status, military mission or military accommodation were not associated with an increased risk of ESBL-E colonization. In the multivariate analysis, a treatment with any antibiotic in the last two months was significantly associated with ESBL-E colonization (OR 6.71, 95% CI 3.36-19.08).

CONCLUSION

Antibiotic treatment in the two previous months is strongly predictive of ESBL-E colonization in international travelers, while the military status and its specific living conditions are not.

Prevalence of multi-drug resistant organisms in stool of paediatric patients with acute leukaemia and correlation with blood culture positivity: A single institution experience

BACKGROUND

Multi-drug resistant (MDR) bacteria are associated with increased morbidity and mortality in children with acute leukaemia. The present study was conducted to assess the prevalence of MDR bacteria in stool cultures of patients with acute leukaemia at presentation to the hospital. The results were then correlated with blood cultures when patients developed septicaemia.

PATIENTS AND METHODS

The study involved analysis of case records of patients with newly diagnosed acute leukaemia less than 18 years of age treated at our centre from January 2015 to December 2015. Stool cultures were sent within 72 hr of hospital admission and blood cultures were sent when clinically indicated. MDR was defined as resistance to at least one antibiotic in three or more following antimicrobial groups: cephalosporins, β-lactam/β-lactamase inhibitor, carbapenems, fluoroquinolones and aminoglycosides.

RESULTS

The analysis included 85 patients with acute leukaemia, among whom 48 of 85 (56%) patients had positive stool cultures and 42 of 85 (50%) patients were positive for MDR bacteria. Blood cultures were positive in 13 of 48 patients (27%, seven MDR and six non-MDR) with positive stool cultures and three of 37 patients (8%, one MDR and two non-MDR) with negative stool cultures (P = 0.01). The concordance between stool and blood culture for similar organism was 61%. There were seven deaths in 48 stool culture positive patients and two deaths in 37 stool culture negative patients.

CONCLUSION

This study shows the high prevalence of MDR bacteria in newly diagnosed children with acute leukaemia. Colonisation with MDR bacteria in stools is associated with increased positivity of blood cultures and mortality.

Genomic Analysis of Third Generation Cephalosporin Resistant Escherichia coli from Dairy Cow Manure

The production of extended-spectrum β-lactamases (ESBLs) conferring resistance to new derivatives of β-lactams is a major public health threat if present in pathogenic Gram-negative bacteria. The objective of this study was to characterize ceftiofur (TIO)- or cefotaxime (FOX)-resistant Escherichia coli isolated from dairy cow manure. Twenty-four manure samples were collected from four farms and incubated under anaerobic conditions for 20 weeks at 4 °C or at 25 °C. A total of 37 TIO- or FOX-resistant E. coli were isolated from two of the four farms to determine their susceptibility to 14 antibiotics. Among the 37 resistant E. coli, 10 different serotypes were identified, with O8:H1 being the predominant serotype (n = 17). Five isolates belonged to each of serotypes O9:NM and O153:H42, respectively. All 37 cephalosporin resistant isolates were multi-resistant with the most prevalent resistance spectrum being amoxicillin-clavulanic acid-ampicillin-cefoxitin-ceftiofur-ceftriaxone-chloramphenicol-streptomycin-sulfisoxazole-tetracycline-trimethoprim-sulfamethoxazole. The genomes of 18 selected isolates were then sequenced and compared to 14 selected human pathogenic E. coli reference genomes obtained from public repositories using different bioinformatics approaches. As expected, all 18 sequenced isolates carried at least one β-lactamase bla gene: TEM-1, TEM-81, CTX-M115, CTX-M15, OXA-1, or CMY-2. Several other antibiotic resistance genes (ARGs) and virulence determinants were detected in the sequenced isolates and all of them harbored antimicrobial resistance plasmids belonging to classic Inc groups. Our results confirm the presence of diverse ESBL producing E. coli isolates in dairy cow manure stored for a short period of time. Such manure might constitute a reservoir of resistance and virulence genes for other bacteria that share the same environment.

Multicenter collaboration study on the β-lactam resistant Enterobacteriaceae in Japan - The 65th anniversary public interest purpose project of the Japanese Society of Chemotherapy

This study was conducted using the same method of the "1-day multicenter collaborative research for Clostridium difficile infectious". This surveillance study was performed by 38 participating medical facilities across Japan. Of the 268 fecal specimens collected in this study, 5 (1.9%) carbapenem-resistant Enterobacteriaceae (CRE) were judged carbapenem resistant by the criteria of the Infectious Disease Act, Japan (2 mg/L or more and 64 mg/L or more MICs for imipenem and cefmetazole, respectively). However, no isolate was shown to have a meropenem MIC of 2 mg/L or more. No carbapenemase encoding genes were detected from the CRE. Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae were detected from 29 specimens (11%), and the predominant ESBL-encoding gene group was bla_CTX-M-9. The predominant ST-type by multilocus sequence typing of ESBL encoding gene-positive Escherichia coli was ST131.

The ecology of extended-spectrum β-lactamases (ESBLs) in the developed world

BACKGROUND

Since the initial appearance in the 1980s, Enterobacteriaceae producing extended-spectrum β-lactamase (ESBL) have increased in prevalence and emerged as a major antimicrobial-resistant pathogen. The source of these antimicrobial-resistant bacteria in the developed world is an area of active investigation.

METHODS

A standard internet search was conducted with a focus on the epidemiology and potential sources of ESBL-producing Enterobacteriaceae in the developed world.

RESULTS

The last decade has witnessed several major changes in the epidemiology of these bacteria: replacement of TEM and SHV-type ESBLs by CTX-M-family ESBLs, emergence of Escherichia coli ST131 as a prevalent vehicle of ESBL, and spread of ESBL-producing E. coli in the community. The most studied potential sources of ESBL-producing Enterobacteriaceae in humans in the community include food and companion animals, the environment and person-to-person transmission, though definitive links are yet to be established. Evidence is emerging that international travel may serve as a major source of introduction of ESBL-producing Enterobacteriaceae into the developed world.

CONCLUSIONS

ESBL-producing Enterobacteriaceae has become a major multidrug-resistant pathogen in the last two decades, especially in the community settings. The multifactorial nature of its expansion poses a major challenge in the efforts to control them.

Consumption of edible ice contaminated with Acinetobacter, Pseudomonas, and Stenotrophomonas is a risk factor for fecal colonization with extended-spectrum β-lactamase-producing Escherichia coli in Vietnam

Although Vietnamese residents frequently harbor extended-spectrum β-lactamase-producing Escherichia coli (ESBL-E), it is unclear which foods/beverages are risk factors for acquiring these bacteria. The aim of this study was to evaluate the frequency with which edible ice served in restaurants is contaminated with antibiotic-resistant bacteria, and thereby clarify whether this product poses a risk for ESBL-E carriage in humans. Ice from restaurants in Vietnam and Japan was screened for bacteria capable of growing on agar containing cefotaxime (BG-CTX). Of the 119 BG-CTX strains isolated in Vietnam, 40%, 39%, and 12% were identified as Pseudomonas spp., Acinetobacter spp., and Stenotrophomonas maltophilia, respectively. Meanwhile, of the six such strains isolated in Japan, five were identified as Acinetobacter spp. and one as Pseudomonas spp. More than 10% of the Acinetobacter isolates exhibited cefotaxime, ceftazidime, and sulfa/trimethoprim resistance, while 21% of Pseudomonas and 14% of S. maltophilia isolates exhibited meropenem and sulfa/trimethoprim resistance, respectively. Subsequent multiplex polymerase chain reaction (PCR) analyses detected ESBL-encoding genes in 10% of the BG-CTX. Notably, feces harvested from mice administered water contaminated with BG-CTX contained E. coli harboring the bla_CTX-M-9 gene. In conclusion, our findings indicate that consumption of contaminated edible ice is a risk factor for human ESBL-E carriage.

Extended-spectrum β-lactamase-producing Enterobacteriaceae colonisation in long-term overseas business travellers

BACKGROUND

International travel is considered a risk for colonisation with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE). To our knowledge, no studies to date have focused on ESBL-PE colonisation among long-term business travellers. Therefore this study aimed to clarify the characteristics associated with ESBL-PE colonisation in Japanese long-term business travellers.

METHODS

Japanese business travellers planning to stay abroad for ≥6 months were enrolled. Of the 192 travellers, 135 provided only post-travel stool samples and 57 provided both pre- and post-travel stool samples. Additionally, microbiological analyses of ESBL-PE strains, including susceptibility tests and polymerase chain reaction amplification of CTX-M genes and their sequencing were performed.

RESULTS

A post-travel survey showed that of the 55 travellers (40.7%) who tested positive for ESBL-PE after travel, the highest proportion was travellers returning from East and Central Asia. CTX-M gene analyses showed that CTX-M-15 was the most frequently observed (55.0%). A pre- and post-travel survey showed that of the 22 travellers (44.9%) acquired ESBL-PE during their travel, with acquisition most frequently observed in travellers returning from South Asia.

CONCLUSION

Risk-based evaluations of ESBL-PE colonisation should be performed not only for regular tourists but also for long-term business travellers.

Acquisition of Extended-Spectrum β-Lactamases by Escherichia coli and Klebsiella pneumoniae in Gut Microbiota of Pilgrims during the Hajj Pilgrimage of 2013

We reported the acquisition of extended-spectrum-β-lactamase (ESBL)-producing bacteria in rectal samples of 129 pilgrims during the 2013 Hajj (pilgrimage to Makkah). When returning from the Hajj, there was a significant increase in the number of pilgrims carrying E. coli resistant to ceftriaxone (P = 0.008). The CTX-M gene was detected in rectal samples, with the detection rate increasing from 10.08% to 32.56% of samples after the Hajj (P < 0.001).

Epidemic potential of Escherichia coli ST131 and Klebsiella pneumoniae ST258: a systematic review and meta-analysis

OBJECTIVES

Observational studies have suggested that Escherichia coli sequence type (ST) 131 and Klebsiella pneumoniae ST258 have hyperendemic properties. This would be obvious from continuously high incidence and/or prevalence of carriage or infection with these bacteria in specific patient populations. Hyperendemicity could result from increased transmissibility, longer duration of infectiousness, and/or higher pathogenic potential as compared with other lineages of the same species. The aim of our research is to quantitatively estimate these critical parameters for E. coli ST131 and K. pneumoniae ST258, in order to investigate whether E. coli ST131 and K. pneumoniae ST258 are truly hyperendemic clones.

PRIMARY OUTCOME MEASURES

A systematic literature search was performed to assess the evidence of transmissibility, duration of infectiousness, and pathogenicity for E. coli ST131 and K. pneumoniae ST258. Meta-regression was performed to quantify these characteristics.

RESULTS

The systematic literature search yielded 639 articles, of which 19 data sources provided information on transmissibility (E. coli ST131 n=9; K. pneumoniae ST258 n=10)), 2 on duration of infectiousness (E. coli ST131 n=2), and 324 on pathogenicity (E. coli ST131 n=285; K. pneumoniae ST258 n=39). Available data on duration of carriage and on transmissibility were insufficient for quantitative assessment. In multivariable meta-regression E. coli isolates causing infection were associated with ST131, compared to isolates only causing colonisation, suggesting that E. coli ST131 can be considered more pathogenic than non-ST131 isolates. Date of isolation, location and resistance mechanism also influenced the prevalence of ST131. E. coli ST131 was 3.2 (95% CI 2.0 to 5.0) times more pathogenic than non-ST131. For K. pneumoniae ST258 there were not enough data for meta-regression assessing the influence of colonisation versus infection on ST258 prevalence.

CONCLUSIONS

With the currently available data, it cannot be confirmed nor rejected, that E. coli ST131 or K. pneumoniae ST258 are hyperendemic clones.

Prevalence, risk factors and molecular epidemiology of highly resistant gram negative rods in hospitalized patients in the Dutch region Kennemerland

Background

This paper describes (1) the Highly Resistant Gram Negative Rod (HR-GNR) prevalence rate, (2) their genotypes, acquired resistance genes and (3) associated risk factors of HR-GNR colonization among the hospitalized population in the Dutch region Kennemerland.

Methods

Between 1 October 2013 and 31 March 2014, cross-sectional prevalence measurements were performed in three regional hospitals as part of each hospitals infection control program. Rectal swabs were analyzed at the Regional Public Health Laboratory Kennemerland by direct culturing. Genotypes and acquired resistance genes of positive isolates were determined using Whole Genome Sequencing with the MiSeq instrument (Illumina). Association between several independent variables and HR-GNR positivity was examined using logistic regression models.

Results

Out of 427 patients, 24 HR-GNR positive isolates were recovered from 22 patients, resulting in a regional HR-GNR colonization prevalence (95 % CI) of 5.2 % (3.6–7.9). Of these 22 positive patients, 15 were Extended Spectrum Beta-Lactamase (ESBL) positive (3.5 % (2.1–5.7)), 7 patients were positive for a Fluoroquinolones and Aminoglycosides (Q&A) resistant Enterobacteriaceae (1.6 % (0.8–3.3)) and from one patient (0.2 % (0–1.3)) a Stenotrophomonas maltophilia resistant towards co-trimoxazole was isolated. No carbapenemase producing Enterobacteriaceae (CPE), multi-resistant Acinetobacter species or multi-resistant Pseudomonas aeruginosa were isolated. The ESBL genes found were bla_CTX-M-1 (n = 4, 25.0 %), bla_CTX-M-15 (n = 3, 18.8 %), bla_CTX-M-27 (n = 2, 12.5 %), bla_CTX-M-14b (n = 2, 12.5 %), bla_CTX-M-9 (n = 2, 12.5 %), bla_CTX-M-14 (n = 1, 6.3 %), bla_CTX-M-3 (n = 1, 6.3 %), bla_SHV-11 (n = 1, 6.3 %) and bla_SHV-12 (n = 1, 6.3 %). Being known HR-GNR positive in the past was the only significant associated risk factor for HR-GNR positivity, odds ratio (95 % CI): 7.32 (1.82–29.35), p-value = 0.005.

Conclusions

Similar ESBL prevalence rates and genotypes (3.5 %) were found in comparison to other Dutch studies. When previously HR-GNR positive patients are readmitted, they should be screened for HR-GNR colonization since colonization with GR-GNRs could be prolonged. We recommend for future studies to include all defined HR-GNRs in addition to ESBLs in prevalence studies, in order to obtain a more comprehensive overview of colonization with HR-GNRs.

High Rate of Acquisition but Short Duration of Carriage of Multidrug-Resistant Enterobacteriaceae After Travel to the Tropics

BACKGROUND

Multidrug-resistant Enterobacteriaceae (MRE) are widespread in the community, especially in tropical regions. Travelers are at risk of acquiring MRE in these regions, but the precise extent of the problem is not known.

METHODS

From February 2012 to April 2013, travelers attending 6 international vaccination centers in the Paris area prior to traveling to tropical regions were asked to provide a fecal sample before and after their trip. Those found to have acquired MRE were asked to send fecal samples 1, 2, 3, 6, and 12 months after their return, or until MRE was no longer detected. The fecal relative abundance of MRE among all Enterobacteriaceae was determined in each carrier.

RESULTS

Among 824 participating travelers, 574 provided fecal samples before and after travel and were not MRE carriers before departure. Of these, 292 (50.9%) acquired an average of 1.8 MRE. Three travelers (0.5%) acquired carbapenemase-producing Enterobacteriaceae. The acquisition rate was higher in Asia (142/196 [72.4%]) than in sub-Saharan Africa (93/195 [47.7%]) or Latin America (57/183 [31.1%]). MRE acquisition was associated with the type of travel, diarrhea, and exposure to β-lactams during the travel. Three months after return, 4.7% of the travelers carried MRE. Carriage lasted longer in travelers returning from Asia and in travelers with a high relative abundance of MRE at return.

CONCLUSIONS

MRE acquisition is very frequent among travelers to tropical regions. Travel to these regions should be considered a risk factor of MRE carriage during the first 3 months after return, but not beyond.

CLINICAL TRIALS REGISTRATION

NCT01526187.