CTX-M-15-non-ST131 Escherichia coli isolates are mainly responsible of faecal carriage with ESBL-producing Enterobacteriaceae in travellers, immigrants and those visiting friends and relatives

The Importance of Carbapenemase-Producing Enterobacterales in African Countries: Evolution and Current Burden

Antimicrobial resistance (AMR) is a worldwide healthcare problem. Multidrug-resistant organisms (MDROs) can spread quickly owing to their resistance mechanisms. Although colonized individuals are crucial for MDRO dissemination, colonizing microbes can lead to symptomatic infections in carriers. Carbapenemase-producing Enterobacterales (CPE) are among the most important MDROs involved in colonizations and infections with severe outcomes. This review aimed to track down the first reports of CPE in Africa, describe their dissemination throughout African countries and summarize the current status of CRE and CPE data, highlighting current knowledge and limitations of reported data. Two database queries were undertaken using Medical Subject Headings (MeSH), employing relevant keywords to identify articles that had as their topics beta-lactamases, carbapenemases and carbapenem resistance pertaining to Africa or African regions and countries. The first information on CPE could be traced back to the mid-2000s, but data for many African countries were established after 2015-2018. Information is presented chronologically for each country. Although no clear conclusions could be drawn for some countries, it was observed that CPE infections and colonizations are present in most African countries and that carbapenem-resistance levels are rising. The most common CPE involved are Klebsiella pneumoniae and Escherichia coli, and the most prevalent carbapenemases are NDM-type and OXA-48-type enzymes. Prophylactic measures, such as screening, are required to combat this phenomenon.

CTX-M-producing Escherichia coli ST602 carrying a wide resistome in South American wild birds: Another pandemic clone of One Health concern

Wild birds have emerged as novel reservoirs and potential spreaders of antibiotic-resistant priority pathogens, being proposed as sentinels of anthropogenic activities related to the use of antimicrobial compounds. The aim of this study was to investigate the occurrence and genomic features of extended-spectrum β-lactamase (ESBL)-producing bacteria in wild birds in South America. In this regard, we have identified two ESBL (CTX-M-55 and CTX-M-65)-positive Escherichia coli (UNB7 and GP188 strains) colonizing Creamy-bellied Thrush (Turdus amaurochalinus) and Variable Hawk (Geranoaetus polyosoma) inhabiting synanthropic and wildlife environments from Brazil and Chile, respectively. Whole-genome sequence (WGS) analysis revealed that E. coli UNB7 and GP188 belonged to the globally disseminated clone ST602, carrying a wide resistome against antibiotics (β-lactams), heavy metals (arsenic, copper, mercury), disinfectants (quaternary ammonium compounds), and pesticides (glyphosate). Additionally, E. coli UNB7 and GP188 strains harbored virulence genes encoding hemolysin E, type II and III secretion systems, increased serum survival, adhesins and siderophores. SNP-based phylogenomic analysis, using an international genome database, revealed genomic relatedness (19-363 SNP differences) of GP188 with livestock and poultry strains, and genomic relatedness (61-318 differences) of UNB7 with environmental, human and livestock strains (Table S1), whereas phylogeographical analysis confirmed successful expansion of ST602 as a global clone of One Health concern. In summary, our results support that ESBL-producing E. coli ST602 harboring a wide resistome and virulome have begun colonizing wild birds in South America, highlighting a potential new reservoir of critical priority pathogens.

High risk of intestinal colonization with ESBL-producing Escherichia coli among soldiers of military contingents in specific geographic regions

One-hundred Polish soldiers of a contingent in Afghanistan in 2019 were screened for Enterobacterales resistant to newer-generation β-lactams at their departure and return. Seventeen percent were colonized in the gut at the departure, whereas 70% acquired carriage in Afghanistan. The commonest organisms were extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-Ec; 96.6%). All isolates were sequenced and were clonally diverse overall, even within the same sequence type, indicating that independent acquisitions mainly. ESBL-Ec were often multi-drug-resistant. Soldiers stationing in certain regions are at high risk of acquiring resistant bacteria that may cause endogenous infection, be transmitted to vulnerable individuals, and spread resistance genes.

Carriage of β-lactamase and carbapenemase-producing Enterobacteriaceae in hospitalized patients at debre tabor comprehensive specialized hospital

Background

Antimicrobial resistance has remained global public health threat. Carriage with drug-resistant bacterial pathogens, particularly beta-lactamase and carbapenemase-producing Enterobacteriaceae is among the most concerning. The purpose of this study was to look into the magnitude, antimicrobial resistance patterns, and associated risk factors among hospitalized patients.

Methods

A facility-based cross-sectional study was conducted on 383 hospitalized patients at Debre Tabor Comprehensive Specialized Hospital between September 2022 and May 2023. A pre-tested structured questionnaire was used to collect sociodemographic and clinical data. The data on the etiologic agent was collected using standard bacteriological techniques. Briefly, stool specimens were collected aseptically into sterile, leak-proof stool cups. The stool sample was inoculated onto MacConkey agar and incubated aerobically at 37 °C for 24 h. The species isolation and antimicrobial resistance patterns were then performed adhering to bacteriological procedures. In the analysis, a p-value of <0.05 was considered statistically significant.

Results

There were 383 study participants, and men made up the majority (55.6%). The study participants' mean age was 33 ± 18 years. Three hundred and seventy-seven (88%) of the study's participants had no previous history of antibiotic use. There were 102 (26.6%) and 21 (5.5%) cases of gastrointestinal carriage caused by Enterobacteriaceae that produce beta-lactamase and carbapenemase, respectively. In total, 175 isolates of Enterobacteriaceae were detected. E. coli (n = 89) and K. pneumoniae (n = 51) were the most frequently recovered. In this study, 46 (79.3%) and 8 (13.8%) isolates of E. coli that produce beta-lactamase were resistant to ampicillin and amoxicillin/clavulanic acid, respectively. Furthermore, participants who had previously used antibiotics experienced a two-fold increase in exposure to gastrointestinal tract carriage by carbapenemase-producing Enterobacteriaceae [AOR, 95% CI (2.01, 1.06-2.98), p = 0.001].

Conclusions

The emergence of drug-resistant pathogens is a growing concern. An increase in the prevalence of drug-resistant infections in hospitalized patients is warranting further investigation.

High level of colonization with 3rd-generation cephalosporin-resistant Enterobacterales in African community settings, Ghana

A cross-sectional survey was conducted in eight Ghanaian communities to investigate the extent of intestinal colonization with 3^rd-generation cephalosporin-resistant Enterobacterales. The study collected faecal samples and corresponding lifestyle data from 736 healthy residents to assess the occurrence of cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae, with a focus on genotypes of plasmid-mediated ESBLs, AmpCs, and carbapenemases. The results showed that 371 participants (50.4%) carried 3^rd-generation cephalosporin-resistant E. coli (n=362) and K. pneumoniae (n=9). Most of these were ESBL-producing E. coli (n=352, 94.9%), carrying CTX-M genes (96.0%, n=338/352), mostly for CTX-M-15 (98.9%, n=334/338). Nine participants (1.2%) carried AmpC-producing E. coli that harboured bla_DHA-1 or blaCMY-2 genes, and two participants (0.3%) each carried a carbapenem-resistant E. coli that harboured both bla_NDM-1 and bla_CMY-2. Quinolone-resistant O25b: ST131 E. coli were recovered from six participants (0.8%) and were all CTX-M-15 ESBL-producers. Having a household toilet facility was significantly associated with a reduced risk of intestinal colonization (adjusted odds ratio, 0.71; 95% CI, 0.48-0.99; P-value=0.0095) in multivariate analysis. These findings raise serious public health concerns, and effective control of the spread of antibiotic-resistant bacteria is possible by providing better sanitary conditions for communities.

The antimicrobial resistance travel tool, an interactive evidence-based educational tool to limit antimicrobial resistance spread

BACKGROUND

International travel has been recognized as a risk factor contributing to the spread of antimicrobial resistance (AMR). However, tools focused on AMR in the context of international travel and designed to guide decision-making are limited. We aimed at developing an evidence-based educational tool targeting both healthcare professionals (HCPs) and international travellers to help prevent the spread of AMR.

METHODS

A literature review on 12 antimicrobial-resistant bacteria (ARB) listed as critical and high tiers in the WHO Pathogen Priority List covering four key areas was carried out: AMR surveillance data; epidemiological studies reporting ARB prevalence data on carriage in returning travellers; guidance documents reporting indications on screening for ARB in returning travellers and recommendations for ARB prevention for the public. The evidence, catalogued at country-level, provided the content for a series of visualizations that allow assessment of the risk of AMR acquisition through travel.

RESULTS

Up to January 2021, the database includes data on: (i) AMR surveillance for 2.018.241 isolates from 86 countries; (ii) ARB prevalence of carriage from 11.679 international travellers and (iii) 15 guidance documents published by major public health agencies. The evidence allowed the development of a consultation scheme for the evaluation of risk factors, prevalence of carriage, proportion and recommendations for screening of AMR. For the public, pre-travel practical measures to minimize the risk of transmission were framed.

CONCLUSIONS

This easy-to-use, annually updated, freely accessible AMR travel tool (https://epi-net.eu/travel-tool/overview/), is the first of its kind to be developed. For HCPs, it can provide a valuable resource for teaching and a repository that facilitates a stepwise assessment of the risk of AMR spread and strengthen implementation of optimized infection control measures. Similarly, for travellers, the tool has the potential to raise awareness of AMR and outlines preventive measures that reduce the risk of AMR acquisition and spread.

Epidermis as a Platform for Bacterial Transmission

The epidermis constitutes a continuous external layer covering the body, offering protection against bacteria, the most abundant living organisms that come into contact with this barrier. The epidermis is heavily colonized by commensal bacterial organisms that help protect against pathogenic bacteria. The highly regulated and dynamic interaction between the epidermis and commensals involves the host’s production of nutritional factors promoting bacterial growth together to chemical and immunological bacterial inhibitors. Signal trafficking ensures the system’s homeostasis; conditions that favor colonization by pathogens frequently foster commensal growth, thereby increasing the bacterial population size and inducing the skin’s antibacterial response, eliminating the pathogens and re-establishing the normal density of commensals. The microecological conditions of the epidermis favors Gram-positive organisms and are unsuitable for long-term Gram-negative colonization. However, the epidermis acts as the most important host-to-host transmission platform for bacteria, including those that colonize human mucous membranes. Bacteria are frequently shared by relatives, partners, and coworkers. The epidermal bacterial transmission platform of healthcare workers and visitors can contaminate hospitalized patients, eventually contributing to cross-infections. Epidermal transmission occurs mostly via the hands and particularly through fingers. The three-dimensional physical structure of the epidermis, particularly the fingertips, which have frictional ridges, multiplies the possibilities for bacterial adhesion and release. Research into the biology of bacterial transmission via the hands is still in its infancy; however, tribology, the science of interacting surfaces in relative motion, including friction, wear and lubrication, will certainly be an important part of it. Experiments on finger-to-finger transmission of microorganisms have shown significant interindividual differences in the ability to transmit microorganisms, presumably due to genetics, age, sex, and the gland density, which determines the physical, chemical, adhesive, nutritional, and immunological status of the epidermal surface. These studies are needed to optimize interventions and strategies for preventing the hand transmission of microorganisms.

Comparative Study of CTX-M-15 Producing Escherichia coli ST131 Clone Isolated from Urinary Tract Infections and Acute Diarrhoea

Background and Purpose

The alarming increase in the prevalence of CTX-M-15 extended-spectrum β-lactamase (ESBL) producing E. coli has been significantly linked to the clonal expansion of emerging sequence type (ST131). This study aimed to screen for the O16/O25-ST131 clones among different phylogenetic types of E. coli strains isolated from urinary and diarrhoeal samples.

Methods

A total of 205 E. coli strains isolated from patients with UTI and acute diarrhoea were investigated by phenotypic and genotypic methods for ESBL identification. Molecular methods were used for identification of O25/O16-ST131 clone and phylogenetic typing of E. coli isolates.

Results

O25-ST131 clone was detected in 89/105 (84.8%) and 47/100 (47%) of urinary and intestinal E. coli isolates, respectively, with a significant difference (P-value<0.001). There was a significant high rate of occurrence of ESBLs, MDR, and antibiotic resistance to most antibiotic classes among O25-ST131 than non-O25-ST131 isolates. CTX-M-15 gene was detected in 64/71 (90%) of ESBLs producing intestinal isolates and 54/79 (68.4%) of urinary ESBLs producing isolates. The O25-ST131 clone was reported among all phylogenetic groups. The O16-ST131 clone serotype was not detected in the study isolates.

Conclusion

High prevalence of the O25-ST131 clone was reported among extraintestinal and intestinal E. coli isolates. First detection of the O25-ST131 clone among phylogenetic groups other than group B2 draws attention of the ability of this clone to transfer among commensal groups. An increasing in the prevalence of CTX-M-15 among E. coli strains especially of intestinal origin is alarming as the intestine is the main reservoir for ExPEC strains causing UTI.

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.

Foraging at Solid Urban Waste Disposal Sites as Risk Factor for Cephalosporin and Colistin Resistant Escherichia coli Carriage in White Storks (Ciconia ciconia)

White stork (Ciconia ciconia) may act as a reservoir and vehicle of cephalosporin resistant (CR) Escherichia coli. Between 2011 and 2014, we sampled white storks from colonies exposed to different degrees of anthropic pressure across the major areas of natural distribution of white storks in Spain. Cloacal swab samples (n = 467) were obtained from individuals belonging to 12 different colonies from six different regions. Additionally, 70 samples were collected from recently deposited droppings at the base of nesting platforms. We phenotypically characterized E. coli isolates, confirmed presence of CR genes and classified plasmids. Risk factors for acquiring these genes were assessed. Overall, 8.8% (41 out of 467) storks carried CR E. coli in their cloaca and five (7.1%) were identified from recently deposited droppings; therefore, 46 isolates were further characterized. Of them, 20 contained bla_CTX–M–1, nine bla_CMY–2, six bla_CTX–M–14, four bla_SHV–12, three bla_CTX–M–15, two bla_CTX–M–32, one bla_CTX–M–1 together with bla_CMY–2, and one bla_CTX–M–1 together with bla_SHV–12. All were multidrug-resistant, and four harbored the plasmid-mediated colistin resistance mcr-1 gene. CR genes were associated with the presence of IncI1, IncFIB, and IncN replicon families. XbaI-macrorestriction analysis revealed a great diversity among most of the XbaI-PFGE types, but indistinguishable types were also seen with isolates obtained from different locations. Clonal complex 10 was the most common among CR E. coli and two bla_CTX–M–15 positive isolates were identified as B2-ST131. Carriage of CR E. coli was significantly higher in colonies located close to solid urban waste disposal sites in which foraging on human waste was more likely and in one case to cattle grazing. The co-occurrence of bla_CMY–2 and mcr-1 on plasmids of E. coli isolated from wild birds as early as 2011 is of note, as the earliest previous report of mcr-1 in wild birds is from 2016. Our study shows that foraging at landfills and in association with cattle grazing are important risk factors for the acquisition of CR E. coli in white storks.

Geographic mapping of Enterobacteriaceae with extended-spectrum β-lactamase (ESBL) phenotype in Pereira, Colombia

Background

Antimicrobial resistance is an ecological and multicausal problem. Infections caused by extended-spectrum β-lactamase producing Enterobacteriaceae (ESBL-E) can be acquired and transmitted in the community. Data on community-associated ESBL-E infections/colonizations in Colombia are scarce. Georeferencing tools can be used to study the dynamics of antimicrobial resistance at the community level.

Methods

We conducted a study of geographic mapping using modern tools based on geographic information systems (GIS). Two study centers from the city of Pereira, Colombia were involved. The records of patients who had ESBL-producing Enterobacteriaceae were reviewed. Antimicrobial susceptibility testing and phenotypic detection of ESBL was done according to CLSI standards.

Results

A population of 415 patients with community-acquired infections/colonizations and 77 hospital discharges were obtained. Geographic distribution was established and heat maps were created. Several hotspots were evidenced in some geographical areas of the south-west and north-east of the city. Many of the affected areas were near tertiary hospitals, rivers, and poultry industry areas.

Conclusions

There are foci of antimicrobial resistance at the community level. This was demonstrated in the case of antimicrobial resistance caused by ESBL in a city in Colombia. Causality with tertiary hospitals in the city, some rivers and the poultry industry is proposed as an explanation of the evidenced phenomenon. Geographic mapping tools are useful for monitoring antimicrobial resistance in the community.

Antibiotic resistance patterns of Escherichia coli in migrants vs non-migrants: a study of 14 561 urine samples

BACKGROUND

To investigate the distribution of urine isolates and antibiotic resistance patterns in the predominant uropathogen Escherichia coli in migrant and non-migrant individuals.

METHODS

We linked a cohort consisting of all migrants obtaining residence as refugees or family-reunited migrants in Denmark between January 1993 and December 2015 to hospital urine samples examined from January 2000 to December 2015 at the Department of Microbiology, University Hospital Hvidovre, Denmark. Samples from non-migrant individuals, Danish-born from Danish parents, were included as comparison. Analysis was carried out using multivariate logistic regression.

RESULTS

There were 14 561 first-time urine samples included, with E. coli being the most prevalent bacterial pathogen. Of the identified isolates, 4686/11 737 were E. coli among non-migrants and 1032/2824 among migrants.Sulfamethoxazol-Trimethoprim (SXT) resistance was found in 34.3% (350/1020) of E. coli isolates among migrants and 23.2% (1070/4619) among non-migrant patients [odds ratio (OR) 1.73, 95% confidence interval (CI): 1.47-2.03]. Ciprofloxacin resistance was found in 5.8% (36/618) of isolates among migrants and 2.2% (67/3092) among non-migrants (OR 2.20, 95% CI: 1.37-3.53). Gentamicin (GEN) resistance was seen in 10.8% (61/565) and 4.7% (110/2328) of isolates (OR 2.33, 95% CI:1.63-3.34), Cefuroxime resistance in 8.5% (87/1019) and 3.4% (158/4618) (OR 2.40, 95% CI:1.77-3.24), Ampicillin (AMP) resistance in 51.4% and 40.8% (OR 1.65, 95% CI: 1.42-1.92) and Piperacillin-Tazobactam resistance in 6.9% (30/432) and 4.2% (65/1532) for migrant and non-migrant patients, respectively. When stratifying according to migrant status, family-reunited had higher odds of resistance than refugees for SXT, GEN and AMP.

CONCLUSIONS

Prevalence of antibiotic resistance was significantly higher in E. coli isolates among migrants, both refugees and family-reunited, than non-migrant patients. Differences could not be explained by comorbidity or income. The results emphasize the importance of urine sample testing in both local-born and migrants before antibiotic start-up and point to the benefit of considering migration to secure individual treatment and equal health outcomes.

Global geographic trends in antimicrobial resistance: the role of international travel

BACKGROUND

Rising antimicrobial resistance (AMR) is a threat to modern medicine, and increasing international mobility facilitates the spread of AMR. Infections with resistant organisms have higher morbidity and mortality, are costlier to treat, result in longer hospital stays and place a greater burden on health systems than infections caused by susceptible organisms. Here we review the role of travel in the international dissemination of AMR and consider actions at the levels of travelers, travel medicine practitioners and policymakers that would mitigate this threat.

RESULTS

Resistant pathogens do not recognize international borders; travelers to areas with high AMR prevalence are likely to be exposed to resistant bacteria and return to their home countries colonized. Medical tourists go between health facilities with drastically different rates of AMR, potentially transmitting highly resistant strains.Drug-resistant bacteria have been found in every continent; however, differences between countries in the prevalence of AMR depend on multiple factors. These include levels of antibiotic consumption (including inappropriate use), access to clean water, adequate sanitation, vaccination coverage, the availability of quality healthcare and access to high-quality medical products.

CONCLUSIONS

Travelers to areas with high levels of AMR should have vaccines up to date, be aware of ways of treating and preventing travelers' diarrhea (other than antibiotic use) and be informed on safe sexual practices. The healthcare systems of low- and middle-income countries require investment to reduce the transmission of resistant strains by improving access to clean water, sanitation facilities and vaccines. Efforts are needed to curb inappropriate antibiotic use worldwide. In addition, more surveillance is needed to understand the role of the movement of humans, livestock and food products in resistance transmission. The travel medicine community has a key role to play in advocating for the recognition of AMR as a priority on the international health agenda.

KEY POLICY RECOMMENDATIONS

AMR is a threat to modern medicine, and international travel plays a key role in the spread of highly resistant strains. It is essential that this is addressed at multiple levels. Individual travelers can reduce antibiotic consumption and the likelihood of infection. Travelers should have up-to-date vaccines and be informed on methods of preventing and treating travelers' diarrhea, other than use of antibiotics and on safe sexual practices, such as condom use. Healthcare facilities need to be aware of the travel history of patients to provide appropriate treatment to those who are at high risk of exposure and to prevent further spread. Internationally, in countries without reliable and universal access to clean water, sanitation and hygiene, investment is needed to reduce the emergence and spread of resistance and ensure the antimicrobials available are of assured quality. High-income countries must ensure their use of antimicrobials is appropriate to reduce selection for AMR. Surveillance across all countries is needed to monitor and respond to this emerging threat.

Fecal Carriage Rate of Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae as a Proxy Composite Indicator of Antimicrobial Resistance in a Community in Thailand

BACKGROUND

Increasing awareness of and understanding about antimicrobial resistance (AMR), promoting changes in behavior, and monitoring of AMR in the community are challenging, as AMR is associated with many contributing factors that are difficult to assess individually. This study aimed to determine the effectiveness of a community-based AMR campaign for improving awareness, understanding, and behavior relating to antibiotic use and AMR in Thailand and to assess if fecal carriage of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae could be a proxy composite indicator of AMR in the community.

METHODS

This study was conducted in 4 communities that are home to approximately 400 000 people. A self-administered questionnaire on awareness, understanding, and behavior relating to antibiotic use and AMR was responded to by 20 521 and 19 634 adults before and immediately after the AMR campaign, respectively, at the household level. Fecal samples were collected from 534 adults before the AMR campaign and from 709 adults at 18 months after the AMR campaign to determine presence of ESBL-producing Enterobacteriaceae.

RESULTS

Awareness, understanding, and behavior relating to antibiotic use and AMR, as assessed by a self-administered questionnaire, were significantly improved after the AMR campaign. The fecal carriage rate of ESBL-producing Enterobacteriaceae decreased from 66.5% before to 44.6% after the AMR campaign (P < .01).

CONCLUSIONS

Our AMR campaign was effective for improving awareness, understanding, and behavior relating to antibiotic use and AMR among people in the community at the household level, and the prevalence of fecal carriage of ESBL-producing Enterobacteriaceae seemed to be decreased after the AMR campaign. Fecal carriage rate of ESBL-producing Enterobacteriaceae may be a proxy composite indicator of AMR in the community.

Changing paradigm of antibiotic resistance amongst Escherichia coli isolates in Indian pediatric population

Antimicrobial resistance happens when microorganisms mutates in manners that render the drugs like antibacterial, antiviral, antiparasitic and antifungal, ineffective. The normal mutation process is encouraged by the improper use of antibiotics. Mutations leading to quinolone resistance occur in a highly conserved region of the quinolone resistance-determining region (QRDR) of DNA gyrAse and topoisomerase IV gene. We analyzed antibiotic resistant genes and single nucleotide polymorphism (SNP) in gyrA and parC genes in QRDR in 120 E. coli isolates (both diarrheagenic and non-pathogenic) recovered from fresh stool samples collected from children aged less than 5 years from Delhi, India. Antibiotic susceptibility testing was performed according to standard clinical and laboratory standards institute (CLSI) guidelines. Phylogenetic analysis showed the clonal diversity and phylogenetic relationships among the E. coli isolates. The SNP analysis depicted mutations in gyrA and parC genes in QRDR. The sul1 gene, responsible for sulfonamide resistance, was present in almost half (47.5%) of the isolates across the diseased and healthy samples. The presence of antibiotic resistance genes in E. coli isolates from healthy children indicate the development, dissemination and carriage of antibiotic resistance in their gut. Our observations suggest the implementation of active surveillance and stewardship programs to promote appropriate antibiotic use and minimizing further danger.

Carriage and population genetics of extended spectrum β-lactamase-producing Escherichia coli in cats and dogs in New Zealand

The incidence of infections with extended spectrum β-lactamase producing Escherichia coli (ESBL-E) is increasing both in humans and animals. There is a paucity of data about the rate of faecal carriage of ESBL-E in pets. In this study, faecal swabs collected from 586 pets (225 cats; 361 dogs) in Auckland, New Zealand, were analysed for the presence of ESBL-E by culture, and a questionnaire was delivered to the owners. The ESBL-E were characterised and data elicited by the questionnaires were used for a multivariable analysis, to investigate the factors associated with faecal ESBL-E carriage. The prevalence of ESBL-E in faecal swabs was 6.4%. The β-lactamase genes detected in the ESBL-E were the blaCTX-M-14 (n = 2) and blaCMY-2 (n = 34). Several isolates displayed multilocus sequence types (ST) associated with human and animal infections. Multiple isolates sharing the same ST displayed different antibiograms and β-lactamase genes, reflecting horizontal gene transfer between and within ST. Variables independently associated with increased odds of ESBL-E carriage were: animal received systemic antimicrobial treatment in the six months before the sampling; presence of household members working in veterinary clinics; presence of household members travelling overseas in the six months before the sampling. We conclude that pets are colonised by ESBL-E which are genotypically similar to the bacteria found to infect humans and animals. The statistical analysis suggested a number of eco-epidemiological factors associated with ESBL-E carriage. In particular, they suggest veterinary clinics may represent hot-spots of antimicrobial resistance.

Treatment of infections caused by multidrug-resistant Gram-negative bacteria: report of the British Society for Antimicrobial Chemotherapy/Healthcare Infection Society/British Infection Association Joint Working Party

The Working Party makes more than 100 tabulated recommendations in antimicrobial prescribing for the treatment of infections caused by multidrug-resistant (MDR) Gram-negative bacteria (GNB) and suggest further research, and algorithms for hospital and community antimicrobial usage in urinary infection. The international definition of MDR is complex, unsatisfactory and hinders the setting and monitoring of improvement programmes. We give a new definition of multiresistance. The background information on the mechanisms, global spread and UK prevalence of antibiotic prescribing and resistance has been systematically reviewed. The treatment options available in hospitals using intravenous antibiotics and in primary care using oral agents have been reviewed, ending with a consideration of antibiotic stewardship and recommendations. The guidance has been derived from current peer-reviewed publications and expert opinion with open consultation. Methods for systematic review were NICE compliant and in accordance with the SIGN 50 Handbook; critical appraisal was applied using AGREE II. Published guidelines were used as part of the evidence base and to support expert consensus. The guidance includes recommendations for stakeholders (including prescribers) and antibiotic-specific recommendations. The clinical efficacy of different agents is critically reviewed. We found there are very few good-quality comparative randomized clinical trials to support treatment regimens, particularly for licensed older agents. Susceptibility testing of MDR GNB causing infection to guide treatment needs critical enhancements. Meropenem- or imipenem-resistant Enterobacteriaceae should have their carbapenem MICs tested urgently, and any carbapenemase class should be identified: mandatory reporting of these isolates from all anatomical sites and specimens would improve risk assessments. Broth microdilution methods should be adopted for colistin susceptibility testing. Antimicrobial stewardship programmes should be instituted in all care settings, based on resistance rates and audit of compliance with guidelines, but should be augmented by improved surveillance of outcome in Gram-negative bacteraemia, and feedback to prescribers. Local and national surveillance of antibiotic use, resistance and outcomes should be supported and antibiotic prescribing guidelines should be informed by these data. The diagnosis and treatment of both presumptive and confirmed cases of infection by GNB should be improved. This guidance, with infection control to arrest increases in MDR, should be used to improve the outcome of infections with such strains. Anticipated users include medical, scientific, nursing, antimicrobial pharmacy and paramedical staff where they can be adapted for local use.

Acquisition and Loss of CTX-M-Producing and Non-Producing Escherichia coli in the Fecal Microbiome of Travelers to South Asia

Escherichia coli strains which produce CTX-M extended-spectrum beta-lactamases are endemic as colonizers of humans and in the environment in South Asia. This study demonstrates that acquisition of CTX-M-producing E. coli (CTX-M-EC) in travelers from the United Kingdom to South Asia is polyclonal, which is likely due to multiple acquisition events from contaminated food and drinking water during travel. CTX-M-EC frequently persists in the fecal microbiome for at least 1 year after acquisition, often alongside newly acquired non-CTX-M E. coli strains. In travelers who acquire CTX-M-EC, pre-travel non-CTX-M E. coli remains as a minority population in the gut until the CTX-M-EC strains are lost. The non-CTX-M strains are then reestablished as the predominant E. coli population. This study has shed light on the dynamics of CTX-M-EC acquisition, colonization, and loss after travel. Future work involving manipulation of nonvirulent resident E. coli could be used to prevent colonization with antibiotic-resistant E. coli.

Over 80% of travelers from the United Kingdom to the Indian subcontinent acquire CTX-M-producing Escherichia coli (CTX-M-EC), but the mechanism of CTX-M-EC acquisition is poorly understood. We aimed to investigate the dynamics of CTX-M-EC acquisition in healthy travelers and how this relates to populations of non-CTX-M-EC in the fecal microbiome. This is a prospective observational study of healthy volunteers traveling from the United Kingdom to South Asia. Fecal samples were collected pre- and post-travel at several time points up to 12 months post-travel. A toothpicking experiment was used to determine the proportion of cephalosporin-sensitive E. coli in fecal samples containing CTX-M-EC. MLST and SNP type of pre-travel and post-travel E. coli were deduced by WGS. CTX-M-EC was acquired by 89% (16/18) of volunteers. Polyclonal acquisition of CTX-M-EC was seen in 8/15 volunteers (all had >3 STs across post-travel samples), suggesting multiple acquisition events. Indistinguishable CTX-M-EC clones (zero SNPs apart) are detectable in serial fecal samples up to 7 months after travel, indicating stable maintenance in the fecal microbiome on return to the United Kingdom in the absence of selective pressure. CTX-M-EC-containing samples were often co-colonized with novel, non-CTX-M strains after travel, indicating that acquisition of non-CTX-M-EC occurs alongside CTX-M-EC. The same pre-travel non-CTX-M strains (<10 SNPs apart) were found in post-travel fecal samples after CTX-M-EC had been lost, suggesting return of the fecal microbiome to the pre-travel state and long-term persistence of minority strains in travelers who acquire CTX-M-EC.

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND

Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings.

METHODS

For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681.

FINDINGS

We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations.

INTERPRETATION

Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration.

FUNDING

UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London.

Travel and the Spread of Drug-Resistant Bacteria

PURPOSE OF REVIEW

The rise in antimicrobial resistance is an urgent public health threat which, in the absence of intervention, may result in a post-antibiotic era limiting the effectiveness of antibiotics to treat both common and serious infections. Globalization and human migration have profoundly contributed to the spread of drug-resistant bacteria. In this review, we summarize the recent literature on the importance of travelers in the spread of drug-resistant bacterial organisms. Our goal was to describe the importance of travel on a variety of clinically relevant drug-resistant bacterial organisms including extended-spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, methicillin-resistant Staphylococcus aureus, Salmonella species, as well as other enteric infections.

RECENT FINDINGS

Travelers from high income countries, visiting low and middle income countries, frequently acquire drug-resistant bacteria, particularly extended-spectrum β-lactamase-producing Enterobacteriaceae. The highest risk is associated with travel to the Indian subcontinent. Multidrug-resistant enteric infections in travelers from Salmonella spp., Campylobacter spp., and Shigella spp. are increasing. Refugees, pilgrimages, and medical tourists are associated with considerable risk of multiple forms of drug resistance. This review highlights the importance of antimicrobial stewardship, infection control, and surveillance; particularly in low and middle income countries. International leadership with global coordination is vital in the battle against antimicrobial resistance.

Detection of Escherichia coli ST131 clonal complex (ST705) and Klebsiella pneumoniae ST15 among faecal carriage of extended-spectrum β-lactamase- and carbapenemase-producing Enterobacteriaceae

PURPOSE

The objective of the present study was to evaluate the prevalence of intestinal colonization with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) and carbapenemase-producing Enterobacteriaceae (CPE) in non-selected hospitalized and non-hospitalized patients from the same geographic area of Madrid.

METHODOLOGY

A total of 501 fecal samples were screened. Diluted samples in saline were cultured in MacConkey agar plates with ceftazidime, cefotaxime, imipenem and meropenem disks. Colonies growing within the inhibition zone of either disk were selected. Characterization of ESBLs and CPEs were performed by PCR and sequencing. The Wider system was used for the bacterial identification. In addition, clonal analysis was carried out for species predominant among the fecal carriage.

KEY FINDINGS

Among the 501 patients enrolled, 43 (8.6 %) carried ESBL-E and 8 (1.6 %) patients exhibited CPE. The main intestinal colonizer among ESBL-E was CTX-M-producing Escherichia coli isolates in both settings (community and hospital). ST131 clonal complex was the most common among faecal ESBL-producing E. coli. All gut carriers of CPE were hospitalized patients, Klebsiella pneumoniae being the most prevalent species. Two OXA-48-producing K. pneumoniae isolates belonging to ST15 were detected.

CONCLUSION

Present study reveals that faecal carriage of ESBL is common among inpatients and outpatients, whereas carbapenemase producers are only present in the hospital setting. Therefore, active surveillance will be useful for reducing transmission of antimicrobial-resistant bacteria and preventing infection.

Extended-spectrum β-lactamase/AmpC- and carbapenemase-producing Enterobacteriaceae in animals: a threat for humans?

There has been a great and long-term concern that extended-spectrum β-lactamase (ESBL)/AmpC- and carbapenemase-producing Enterobacteriaceae occurring in animals may constitute a public-health issue. A large number of factors with complex interrelations contribute to the spread of those bacteria among animals and humans. ESBL/AmpC- or carbapenemase-encoding genes are most often located on mobile genetic elements favouring their dissemination. Some shared reservoirs of ESBL/AmpC or carbapenemase genes, plasmids or clones have been identified and suggest cross-transmissions. Even though exposure to animals is regarded as a risk factor, evidence for a direct transfer of ESBL/AmpC-producing bacteria from animals to humans through close contacts is limited. Nonetheless, the size of the commensal ESBL/AmpC reservoir in non-human sources is dramatically rising. This may constitute an indirect risk to public health by increasing the gene pool from which pathogenic bacteria can pick up ESBL/AmpC/carbapenemase genes. The extent to which food contributes to potential transmission of ESBL/AmpC producers to humans is also not well established. Overall, events leading to the occurrence of ESBL/AmpC- and carbapenemase-encoding genes in animals seem very much multifactorial. The impact of animal reservoirs on human health still remains debatable and unclear; nonetheless, there are some examples of direct links that have been identified.

The occurrence of ESBL-producing Escherichia coli carrying aminoglycoside resistance genes in urinary tract infections in Saudi Arabia

Background

The infection and prevalence of extended-spectrum β-lactamases (ESBLs) is a worldwide problem, and the presence of ESBLs varies between countries. In this study, we investigated the occurrence of plasmid-mediated ESBL/AmpC/carbapenemase/aminoglycoside resistance gene expression in Escherichia coli using phenotypic and genotypic techniques.

Methods

A total of 58 E. coli isolates were collected from hospitals in the city of Makkah and screened for the production of ESBL/AmpC/carbapenemase/aminoglycoside resistance genes. All samples were subjected to phenotypic and genotypic analyses. The antibiotic susceptibility of the E. coli isolates was determined using the Vitek-2 system and the minimum inhibitory concentration (MIC) assay. Antimicrobial agents tested using the Vitek 2 system and MIC assay included the expanded-spectrum (or third-generation) cephalosporins (e.g., cefoxitin, cefepime, aztreonam, cefotaxime, ceftriaxone, and ceftazidime) and carbapenems (meropenem and imipenem). Reported positive isolates were investigated using genotyping technology (oligonucleotide microarray-based assay and PCR). The genotyping investigation was focused on ESBL variants and the AmpC, carbapenemase and aminoglycoside resistance genes. E. coli was phylogenetically grouped, and the clonality of the isolates was studied using multilocus sequence typing (MLST).

Results

Our E. coli isolates exhibited different levels of resistance to ESBL drugs, including ampicillin (96.61%), cefoxitin (15.25%), ciprofloxacin (79.66%), cefepime (75.58%), aztreonam (89.83%), cefotaxime (76.27%), ceftazidime (81.36%), meropenem (0%) and imipenem (0%). Furthermore, the distribution of ESBL-producing E. coli was consistent with the data obtained using an oligonucleotide microarray-based assay and PCR genotyping against genes associated with β-lactam resistance. ST131 was the dominant sequence type lineage of the isolates and was the most uropathogenic E. coli lineage. The E. coli isolates also carried aminoglycoside resistance genes.

Conclusions

The evolution and prevalence of ESBL-producing E. coli may be rapidly accelerating in Saudi Arabia due to the high visitation seasons (especially to the city of Makkah). The health authority in Saudi Arabia should monitor the level of drug resistance in all general hospitals to reduce the increasing trend of microbial drug resistance and the impact on patient therapy.

Polyclonal Intestinal Colonization with Extended-Spectrum Cephalosporin-Resistant Enterobacteriaceae upon Traveling to India

We aimed to assess the intestinal colonization dynamics by multiple extended-spectrum cephalosporin-resistant Enterobacteriaceae (ESC-R-Ent) clones in Swiss travelers to India, a country with high prevalence of these multidrug-resistant pathogens. Fifteen healthy volunteers (HVs) colonized with ESC-R-Ent after traveling to India who provided stools before, after, and at 3- and 6-month follow-up are presented in this study. Stools were enriched in a LB broth containing 3 mg/L cefuroxime and plated in standard selective media (BLSE, ChromID ESBL, Supercarba) to detect carbapenem- and/or ESC-R-Ent. At least 5 Enterobacteriaceae colonies were analyzed for each stool provided. All strains underwent phenotypic tests (MICs in microdilution) and molecular typing to define bla genes (microarray, PCR/sequencing), clonality (MLST, rep-PCR), and plasmid content. While only three HVs were colonized before the trip, all participants had positive stools after returning, but the colonization rate decreased during the follow-up period (i.e., six HVs were still colonized at both 3 and 6 months). More importantly, polyclonal acquisition (median of 2 clones, range 1–5) was identified at return in all HVs. The majority of the Escherichia coli isolates belonged to phylogenetic groups A and B1 and to high diverse non-epidemic sequence types (STs); however, 15% of them belonged to clonal complex 10 and mainly possessed bla_CTX−M−15 genes. F family plasmids were constantly found (~80%) in the recovered ESC-R-Ent. Our results indicate a possible polyclonal acquisition of the ESC-R-Ent via food-chain and/or through an environmental exposure. For some HVs, prolonged colonization in the follow-up period was observed due to clonal persistence or presence of the same plasmid replicon types in a new bacterial host. Travel medicine practitioners, clinicians, and clinical microbiologists who are facing the returning travelers and their samples for different reasons should be aware of this important phenomenon, so that better infection control measures, treatment strategies, and diagnostic tests can be adopted.

Escherichia coli β-Lactamases: What Really Matters

Escherichia coli strains belonging to diverse pathotypes have increasingly been recognized as a major public health concern. The β-lactam antibiotics have been used successfully to treat infections caused by pathogenic E. coli. However, currently, the utility of β-lactams is being challenged severely by a large number of hydrolytic enzymes – the β-lactamases expressed by bacteria. The menace is further compounded by the highly flexible genome of E. coli, and propensity of resistance dissemination through horizontal gene transfer and clonal spread. Successful management of infections caused by such resistant strains requires an understanding of the diversity of β-lactamases, their unambiguous detection, and molecular mechanisms underlying their expression and spread with regard to the most relevant information about individual bacterial species. Thus, this review comprises first such effort in this direction for E. coli, a bacterial species known to be associated with production of diverse classes of β-lactamases. The review also highlights the role of commensal E. coli as a potential but under-estimated reservoir of β-lactamases-encoding genes.

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.