High prevalence of multidrug resistant ESBL- and plasmid mediated AmpC-producing clinical isolates of Escherichia coli at Maputo Central Hospital, Mozambique

The resistance patterns and molecular characteristics of ESBL/AmpC-producing Escherichia coli from captive panda ecosystem in China

Escherichia coli (E. coli) plays an important ecological role, and is a useful bioindicator to recognize the evolution of resistance in human, animal and environment. Recently, extended-spectrum β-lactamases (ESBL) producing E.coli has posed a threat to public health. Generally, captive healthy giant pandas are not exposed to antibiotics; however, they still acquire antimicrobial resistant bacteria. In order to understand whether there is an exchange of resistance genes within the ecosystems of captive giant pandas, this study explored resistance characteristics of 330 commensal E. coli isolates from feces of giant pandas, the surroundings, and breeders. Isolates from different sources showed similar resistance phenotype, and ESBL/AmpC-producing isolates showed more profound resistance to antibiotics than non-ESBL/AmpC-producing isolates (P<0.05). Furthermore, the occurrence of broad-spectrum β-lactamase related resistance genes and colistin resistance genes was detected, and isolates phylogenetic typing and multilocus sequence typing (MLST) were applied in this study. Seven different β-lactamase resistance genes (blaCTX-M-55, blaCTX-M-15, blaCTX-M-27, blaCTX-M-65, blaTEM-1, blaOXA-1 and blaCMY) and mcr-1 were found in 68 ESBL/AmpC-producing isolates. blaCTX-M-55 (48.53 %) was found the most predominant resistance genes, followed by blaTEM-1 (19.12 %) and blaCTX-M-27 (16.18 %). Nonetheless, blaCTX-M-55 was commonly detected in the isolates from giant pandas (63.16 %), the surroundings (43.48 %), and breeders (33.33 %). However, there were no carbapenemase genes detected in this study. mcr-1 was harbored in only one isolate from giant panda. Forty-five tansconjugants were successfully obtained in the conjugation experiments. The presence of antimicrobial resistance and related resistance genes tested were observed in the transconjugants. The results indicated that 52.63 % of the isolates from giant panda 73.91 % of the isolates from surroundings, and 100 % of the isolates from breeders were phylogroup A. Total of 27 sequence types (ST) were recognized from the isolate by MLST and found that ST48 (19/68; 27.94 %) was the predominant ST type, especially in the isolates from giant pandas and the surroundings. In conclusion, commensal ESBL/AmpC-producing E. coli becomes a reservoir of ESBL resistance genes, which is a potential threaten to health of giant pandas. The interaction between giant pandas, surroundings and breeders contribute to development of resistant phenotypes and genotypes which might transfer across species or the surroundings easily; hence, strict monitoring based on a "One Health" approach is recommended.

Prevalence and distribution pattern of AmpC β-lactamases in ESBL producing clinical isolates of Klebsiella spp. in parts of Assam, India

The production of extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases is the most common explanation of multidrug resistance in clinical isolates of Klebsiella spp. In the present study, a total of 160 isolates of Klebsiella spp. were procured from the DBT-NER project with ethical clearance no. DU/Dib/ECBHR(Human)/2021-22/02). These were collected from various health settings of Assam and identified as drug-resistant. The isolates were screened for antibiotic susceptibility and phenotypic tests were performed on multidrug resistant isolates to confirm ESBL and AmpC β-lactamases production. The distribution pattern of ESBL and AmpC β-lactamase genotype was investigated by polymerase chain reaction (PCR). The results showed that among 107 multidrug-resistant (MDR) isolates of Klebsiella spp., 67.28% of isolates were ESBL producers and 56.07% were potential AmpC producers. The PCR results revealed that blaCTX-M was the most prevalent ESBL genotype. Among the ESBL producers, 11.11% of isolates showed co-occurrence with plasmid-mediated AmpC β lactamases genotype which indicated the high prevalence of ESBL and AmpC co-producers in K. pneumoniae and K. oxytoca, suggesting the possibility of serious public health concerns. Therefore, it is crucial to regularly monitor the spread of multidrug resistance among clinical isolates.

Comparison of antibiotic-resistant Escherichia coli and extra-intestinal pathogenic E. coli from main river basins under different levels of the sewer system development

Antimicrobial-resistant Escherichia coli in the aquatic environments is considered a strong indicator of sewage or animal waste contamination and antibiotic pollution. Sewer construction and wastewater treatment plant (WWTP) infrastructure may serve as concentrated point sources of contamination of antibiotic-resistant bacteria and antibiotic resistance genes. In this study, we focused on the distribution of antimicrobial-resistant E. coli in two rivers with large drainage areas and different urbanisation levels. E. coli from Kaoping River with drainage mainly from livestock farming had higher resistance to antibiotics (e.g. penicillins, tetracyclines, phenicols, aminoglycosides, and sulpha drugs) and presented more positive detection of antibiotic-resistance genes (e.g. ampC, blaTEM, tetA, and cmlA1) than that from Tamsui River. In Kaoping River with a lower percentage of sewer construction nearby (0-30%) in contrast to a higher percentage of sewer construction (55-92%) in Tamsui River, antimicrobial-resistant E. coli distribution was related to livestock farming waste. In Tamsui River, antimicrobial resistant E. coli isolates were found more frequently in the downstream drainage area of WWTPs with secondary water treatment than that of WWTPs with tertiary water treatment. The Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR showed that the fingerprinting group was significantly related to the sampling site (p < 0.01) and sampling date (p < 0.05). By utilising ERIC-PCR in conjunction with antibiotic susceptibility and antibiotic-resistance gene detection, the relationship among different strains of E. coli could be elucidated. Furthermore, we identified the presence of six extra-intestinal pathogenic E. coli isolates and antibiotic-resistant E. coli isolates near drinking water sources, posing a potential risk to public health through community transmission. In conclusion, this study identified environmental factors related to antibiotic-resistant bacteria and antibiotic-resistance gene contamination in rivers during urban development. The results facilitate the understanding of specific management of different waste streams across different urban areas. Periodic surveillance of the effects of WWTPs and livestock waste containing antibiotic-resistant bacteria and antibiotic-resistance genes on river contamination is necessary.

Polyclonal Multidrug ESBL-Producing Klebsiella pneumoniae and Emergence of Susceptible Hypervirulent Klebsiella pneumoniae ST23 Isolates in Mozambique

Globally, antibiotic-resistant Klebsiella spp. cause healthcare-associated infections with high mortality rates, and the rise of hypervirulent Klebsiella pneumoniae (hvKp) poses a significant threat to human health linked to community-acquired infections and increasing non-susceptibility. We investigated the phenotypic and genetic features of 36 Klebsiella isolates recovered from invasive infections at Hospital Central of Maputo in Mozambique during one year. The majority of the isolates displayed multidrug resistance (MDR) (29/36) to cephalosporins, gentamicin, ciprofloxacin, and trimethoprim-sulfamethoxazole but retained susceptibility to amikacin, carbapenems, and colistin. Most isolates were ESBLs-producing (28/36), predominantly carrying the blaCTX-M-15 and other beta-lactamase genes (blaSHV, blaTEM-1, and blaOXA-1). Among the 16 genomes sequenced, multiple resistance genes from different antibiotic classes were identified, with blaCTX-M-15, mostly in the ISEcp1-blaCTX-M-15-orf477 genetic environment, co-existing with blaTEM-1 and aac(3)-IIa in five isolates. Our results highlight the presence of polyclonal MDR ESBL-producing K. pneumoniae from eight sequence types (ST), mostly harbouring distinct yersiniabactin within the conjugative integrative element (ICE). Further, we identified susceptible hvKp ST23, O1-K1-type isolates carrying yersiniabactin (ybt1/ICEKp10), colibactin, salmochelin, aerobactin, and hypermucoid locus (rmpADC), associated with severe infections in humans. These findings are worrying and underline the importance of implementing surveillance strategies to avoid the risk of the emergence of the most threatening MDR hvKp.

Moving from assessments to implementation: promising practices for strengthening multisectoral antimicrobial resistance containment capacity

BACKGROUND

Antimicrobial resistance (AMR) poses a global threat to human, animal, and environmental health. AMR is a technical area in the Global Health Security Agenda initiative which uses the Joint External Evaluation tool to evaluate national AMR containment capacity. This paper describes four promising practices for strengthening national antimicrobial resistance containment capacity based on the experiences of the US Agency for International Development's Medicines, Technologies, and Pharmaceutical Services Program work with 13 countries to implement their national action plans on AMR in the areas of multisectoral coordination, infection prevention and control, and antimicrobial stewardship.

METHODS

We use the World Health Organization (WHO) Benchmarks on International Health Regulations Capacities (2019) to guide national, subnational, and facility actions that advance Joint External Evaluation capacity levels from 1 (no capacity) to 5 (sustainable capacity). Our technical approach is based on scoping visits, baseline Joint External Evaluation scores, benchmarks tool guidance, and country resources and priorities.

RESULTS

We gleaned four promising practices to achieve AMR containment objectives: (1) implement appropriate actions using the WHO benchmarks tool, which prioritizes actions, making it easier for countries to incrementally increase their Joint External Evaluation capacity from level 1 to 5; (2) integrate AMR into national and global agendas. Ongoing agendas and programs at international, regional, and national levels provide opportunities to mainstream and interlink AMR containment efforts; (3) improve governance through multisectoral coordination on AMR. Strengthening multisectoral bodies' and their technical working groups' governance improved functioning, which led to better engagement with animal/agricultural sectors and a more coordinated COVID-19 pandemic response; and (4) mobilize and diversify funding for AMR containment. Long-term funding from diversified funding streams is vital for advancing and sustaining countries' Joint External Evaluation capacities.

CONCLUSIONS

The Global Health Security Agenda work has provided practical support to countries to frame and conduct AMR containment actions in terms of pandemic preparedness and health security. The WHO benchmarks tool that Global Health Security Agenda uses serves as a standardized organizing framework to prioritize capacity-appropriate AMR containment actions and transfer skills to help operationalize national action plans on AMR.

Epidemiology of extended-spectrum β-lactamases in Enterobacterales in Taiwan for over two decades

The emergence of antimicrobial resistance among microorganisms is a serious public health concern, and extended-spectrum β-lactamases (ESBL)-producing Enterobacterales is one of the major concerns among antibiotic-resistant bacteria. Although the prevalence of ESBL in Enterobacterales has been increasing with time, the prevalence of ESBL could differ according to the species, hospital allocation, sources of infections, nosocomial or community acquisitions, and geographic regions. Therefore, we conducted a comprehensive review of the epidemiology of ESBL-producing Enterobacterales in Taiwan. Overall, the rates of ESBL producers are higher in northern regions than in other parts of Taiwan. In addition, the genotypes of ESBL vary according to different Enterobacterales. SHV-type ESBLs (SHV-5 and SHV-12) were the major types of Enterobacter cloacae complex, but Serratia marcescens, Proteus mirabilis, Escherichia coli, and Klebsiella pneumoniae were more likely to possess CTX-M-type ESBLs (CTX-M-3 and CTX-M-14). Moreover, a clonal sequence type of O25b-ST131 has been emerging among urinary or bloodstream E. coli isolates in the community in Taiwan, and this clone was potentially associated with virulence, ESBL (CTX-M-15) production, ciprofloxacin resistance, and mortality. Finally, the evolution of the genetic traits of the ESBL-producing Enterobacterales isolates helps us confirm the interhospital and intrahospital clonal dissemination in several regions of Taiwan. In conclusion, continuous surveillance in the investigation of ESBL production among Enterobacterales is needed to establish its long-term epidemiology.

Multidrug-Resistant ESBL-Producing E. coli in Clinical Samples from the UK

Globally, cephalosporin therapy failure is a serious problem for infection control. One causative agent of cephalosporin-resistant infections is multidrug-resistant (MDR) E. coli producing extended-spectrum β-lactamases (ESBLs) and/or plasmid-encoded AmpC (pAmpC) β-lactamases. We evaluated the occurrence of ESBL/pAmpC genetic determinants in phenotypically MDR E. coli isolated from clinical samples of blood, faeces, ear effusion, urine and sputum from a UK hospital. Phenotypic resistance profiling for 18 antibiotics (from seven classes) showed that 32/35 isolates were MDR, with resistance to 4-16 of the tested antibiotics. Of the isolates, 97.1% showed resistance to ampicillin, 71.4% showed resistance to co-amoxiclav, cefotaxime, ceftazidime and ceftiofur, and 68.5% showed resistance to cefquinome. bla_CTX-M, bla_TEM and bla_OXA-1 genes were detected in 23, 13 and 12 strains, respectively, and Intl1 was detected in 17 isolates. The most common subtypes among the definite sequence types were CTX-M-15 (40%) and TEM-1 (75%). No E. coli isolates carried pAmpC genes. Significant correlations were seen between CTX-M carriage and cefotaxime, ceftiofur, aztreonam, ceftazidime and cefquinome resistance; between bla_CTX-M, bla_TEM and bla_OXA-1 carriage and ciprofloxacin resistance; and between Intl1 carriage and trimethoprim/sulfamethoxazole resistance. Thus, MDR phenotypes may be conferred by a relatively small number of genes. The level and pattern of antibiotic resistance highlight the need for better antibiotic therapy guidelines, including reduced use and improved surveillance.

Bacterial Resistance in Hospital-Acquired Infections Acquired in the Intensive Care Unit: A Systematic Review

PURPOSE

In this review we present the status of the prevalence of bacteria resistant to antibiotics and the main antibiotic resistance genes that are reported in infections acquired in intensive care units (ICU) around the world.

METHODS

A systematic review based on the PRISMA guide was carried out, from the Science Direct, Redalyc, Scopus, Hinari, Scielo, Dialnet, PLOS, ProQuest, Taylor, Lilacs and PubMed/Medline databases. Inclusion criteria of this review were original research study published in a scientific journal in a 10-year time span from 1 January 2017 and 30 April 2022.

RESULTS

A total of 1686 studies were identified, but only 114 studies were considered eligible for inclusion. Klebsiella pneumoniae and Escherichia coli resistant to carbapenems and producers of extended-spectrum β-lactamases (ESBL) are the most frequently isolated pathogens in ICUs in Asia, Africa and Latin America. The blaOXA and blaCTX were antibiotic resistance genes (ARG) most commonly reported in different geographic regions (in 30 and 28 studies, respectively). Moreover, multidrug-resistant (MDR) strains were reported in higher frequency in hospital-acquired infections. Reports of MDR strains vary between continents, with the majority of publications being in Asia and between countries, with Egypt and Iran being highlighted. There is a predominance of few bacterial clones with MDR phenotype, for example, clonal complex 5 Methicillin-Resistant Staphylococcus aureus (CC5-MRSA) circulates frequently in hospitals in the United States, clone ST23-K. pneumoniae is reported in India and Iran, and clone ST260 carbapenemase-producing P. aeruginosa in the United States and Estonia.

CONCLUSION

Our systematic review reveals that ESBL- and carbapenemase-producing K. pneumoniae and E. coli are the most problematic bacteria that are reported, mainly in tertiary hospitals in Asia, Africa, and Latin America. We have also found propagation of dominant clones with a high degree of MDR, becoming a problem due to its high capacity to cause morbidity, mortality and additional hospital costs.

Molecular Epidemiological Characterisation of ESBL- and Plasmid-Mediated AmpC-Producing Escherichia coli and Klebsiella pneumoniae at Kamuzu Central Hospital, Lilongwe, Malawi

The global rise in infections caused by multidrug resistant (MDR) Enterobacterales poses a public health problem. We have performed a molecular epidemiological characterisation of representative plasmid-mediated AmpC (pAmpC) and ESBL-positive clinical isolates of Escherichia coli (n = 38) and Klebsiella pneumoniae (n = 17) from a tertiary hospital in Malawi collected in 2017. Bla_CTX-M-15 was the most prevalent ESBL-determinant in E. coli (n = 30/38) and K. pneumoniae (n = 17/17), whereas bla_CMY-2 was detected in nearly all AmpC-phenotype E. coli (n = 15/17). Whole genome sequencing revealed dominant globally disseminated E. coli sequence types (STs); ST410 (n = 16), ST131 (n = 7), and ST617 (n = 6). The ST distribution in K. pneumoniae was more diverse but included ST101 (n = 2), ST14 (n = 2), and ST340 (n = 2), all considered high-risk MDR clones. The isolates expressed an MDR profile, including resistance against commonly used antibiotics, such as fluoroquinolones, aminoglycosides, and/or trimethoprim-sulfamethoxazole, and harboured corresponding resistance determinants. Clonal analyses of the major STs of E. coli revealed closely related genetic clusters within ST410, ST131, and ST617 supporting within-hospital transmission between patients and/or via a common reservoir. The overall findings add to the limited knowledge on the molecular epidemiology of MDR E. coli and K. pneumoniae in Malawi and may help health policy makers to identify areas to target when addressing this major threat of antibiotic resistance.

Occurrence and genetic characteristics of multidrug-resistant Escherichia coli isolates co-harboring antimicrobial resistance genes and metal tolerance genes in aquatic ecosystems

Multidrug-resistant (MDR) Escherichia coli isolates (n = 50) were recovered from aquatic ecosystems, which presented high counts of E. coli and metal values within the recommended range. These isolates showed different multidrug resistance profiles, highlighting the resistance to extended-spectrum cephalosporins, polymyxins, and fluoroquinolones. Several antimicrobial resistance genes (ARGs) were found, spotlighting the presence of at least one β-lactamase-encoding gene in each E. coli isolate. Substitutions in the quinolone resistance-determining regions and the two-component systems involving PhoP/PhoQ and PmrA/PmrB were also found. The metal tolerance gene rcnA (nickel and cobalt efflux pump) was the most prevalent. In this regard, 94% of E. coli isolates presented the co-occurrence of at least one ARG and metal tolerance gene. Furthermore, virulence genes and genetic diversity were found among MDR E. coli isolates. The emergence of potentially pathogenic isolates exhibiting multidrug resistance and metal tolerance emerged as a global health problem at the human-animal-environment interface.

Systematic Review of Plasmid AmpC Type Resistances in Escherichia coli and Klebsiella pneumoniae and Preliminary Proposal of a Simplified Screening Method for ampC

Beta-lactamase (BL) production is a major public health problem. Although not the most frequent AmpC type, AmpC-BL is increasingly isolated, especially plasmid AmpC-BL (pAmpC-BL). The objective of this study was to review information published to date on pAmpC-BL in Escherichia coli and Klebsiella pneumoniae, and on the epidemiology and detection methods used by clinical microbiology laboratories, by performing a systematic review using the MEDLINE PubMed database. The predictive capacity of a screening method to detect AmpC-BL using disks with cloxacillin (CLX) was also evaluated by studying 102 Enterobacteriaceae clinical isolates grown in CHROMID ESBL medium with the addition of cefepime (FEP), cefoxitin (FOX), ertapenem (ETP), CLX, and oxacillin with CLX. The review, which included 149 publications, suggests that certain risk factors (prolonged hospitalization and previous use of cephalosporins) are associated with infections by pAmpC-BL-producing microorganisms. The worldwide prevalence has increased over the past 10 years, with a positivity rate ranging between 0.1 and 40%, although AmpC was only detected when sought in a targeted manner. CMY-2 type has been the most prevalent pAmpC-BL-producing microorganism. The most frequently used phenotypic method has been the double-disk synergy test (using CLX disks or phenyl-boronic acid and cefotaxime [CTX] and ceftazidime) and the disk method combined with these inhibitors. In regard to screening methods, a 1-µg oxacillin disk with CLX showed 88.9% sensitivity, 100% specificity, 100% positive predictive value (PPV), 98.9% negative predictive value (NPV), and 98.9% validity index (VI). This predictive capacity is reduced with the addition of extended-spectrum beta-lactamases, showing 62.5% sensitivity, 100% specificity, 100% PPV, 93.5% NPV, and 94.1% VI. In conclusion, there has been a worldwide increase in the number of isolates with pAmpC-BL, especially in Asia, with CMY-2 being the most frequently detected pAmpC-BL-producing type of microorganism. Reduction in its spread requires routine screening with a combination of phenotypic methods (with AmpC inhibitors) and genotypic methods (multiplex PCR). In conclusion, the proposed screening technique is an easy-to-apply and inexpensive test for the detection of AmpC-producing isolates in the routine screening of multidrug-resistant microorganisms.

Polyclonal emergence of MDR Enterobacter cloacae complex isolates producing multiple extended spectrum beta-lactamases at Maputo Central Hospital, Mozambique

Enterobacter spp. are important nosocomial pathogens responsible of a wide variety of infections, mainly due to Extended Spectrum β-Lactamase (ESBL) producing isolates, constituting a global public health issue in terms of clinical treatment and infection control, especially in low-income countries, where last-line treatment is often unavailable and there is weak nosocomial surveillance. In this study, we conducted a phenotypic and molecular characterization of 8 clinical Enterobacter spp. strains, isolated from patient’s blood in three hospitals in Mozambique. Isolates were identified by MALDI-TOF and antimicrobial Susceptibility Testing was performed by VITEK 2 system. Half of isolates were analyzed by PCR for β-lactamases genes, other isolates by Whole Genome Sequencing. We identified all isolates as Enterobacter cloacae complex (ECC), those from Maputo Central Hospital were polyclonal, multidrug resistant (5/8), and ESBL producers (50%), carrying blaCTX-M-15 and different assortment of blaSHV-12, blaTEM-1B and blaOXA-1, and AmpCs blaCMH-3, blaACT-7 and blaACT-9 genes. Resistance determinants linked to fluoroquinolone (aac(6')Ib-cr and qnrB1) and others antimicrobials were also found. Notably, one isolate showed phenotypically resistance to colistin, while another colistin susceptible isolate carried a silent mcr-9 gene. ECC nosocomial surveillance is urgently needed to contain and prevent the dissemination of ESBLs producing clones, and mcr-9 spread to other Enterobacteriaceae.

Antimicrobial susceptibility profiles of clinically important bacterial pathogens at the Kamuzu Central Hospital in Lilongwe, Malawi

BACKGROUND

The aim of this prospective study was to ascertain antimicrobial resistance (AMR) in clinical bacterial pathogens from in-hospital adult patients at a tertiary hospital in Lilongwe, Malawi.

METHODS

Clinical specimens (blood culture, pus, urine and cerebrospinal fluid) collected during June to December 2017 were examined for bacterial growth in standard aerobic conditions. One specimen per patient was included. Antimicrobial susceptibility testing (AST) was performed using the disk diffusion method and interpreted according to EUCAST guidelines.

RESULTS

A total of 694 specimens were collected during the study period, of which 336 (48%) specimen yielded visible bacterial growth. Of the 336 specimens, a total of 411 phenotypically different isolates were recovered. Of the 411 isolates, 84 isolates (20%) were excluded and the remaining 327 (80%) were further characterised. The characterised isolates were identified as ESKAPE pathogens (n=195/327; 60%), Escherichia coli (n=92/327; 28%), Proteus mirabilis (n=33/327; 10) or Salmonella spp. (n=7/327; 2%) and were included for further analysis. The excluded isolates (n=84) comprised of coagulase-negative staphylococci (n=25), streptococci (n=33), and low-prevalence Gram-negative bacilli (n=26). E. coli (n=92; 28%) and S. aureus (n=86; 26%) were the most dominant species. A multidrug resistant (MDR) extended spectrum β- lactamase (ESBL)-positive phenotype was detected in Klebsiella pneumoniae (n=20/29; 69%) and E. coli (n=49/92; 53%). One third of the Pseudomonas aeruginosa isolates were resistant to meropenem (MEM), but did not appear to be carbapenemase-producers. Methicillin resistant Staphylococcus aureus (MRSA) was molecularly confirmed in 10.5% of S. aureus (n=9/86).

CONCLUSION

The high proportion of the MDR ESBL-phenotype in clinical isolates of Enterobacterales, strongly limits antimicrobial treatment options and has consequences for empirical and targeted antimicrobial treatment as well as clinical microbiology services and hospital infection control. There is need for a continuous surveillance and an antimicrobial stewardship (AMS) program to contain and prevent the spread of AMR.

Characterization of Escherichia coli from Water and Food Sold on the Streets of Maputo: Molecular Typing, Virulence Genes, and Antibiotic Resistance

The aim of this study was to investigate the pathogenic potential and antibiotic resistance of 59 Escherichia coli isolates from ready-to-eat (RTE) street food (n = 31) and drinking water (n = 28) sold in the city of Maputo, Mozambique. The isolates were characterized by XbaI subtyping analysis via pulsed field gel electrophoresis. Multiplex PCRs were performed targeting five virulence genes (stx, lt, st, astA, and eae) and three groups of antibiotic-resistant genes, namely ß-lactamases (extended-spectrum ß-lactamase and AmpC), tetracycline (tetA, tetB, and tetM) and sulfamethoxazole/trimethoprim (sul1, sul2, and sul3). The stx virulence gene, encoding the Shiga/Vero (VT) toxin produced by the verotoxin-producing E. coli (VTEC), was identified with similar frequency in isolates from food (5/31) and water (6/28). The highest percentages of resistant isolates from food and water were found for ß-lactams imipenem (35.5 and 39.3%, respectively) and ampicillin (39.3 and 46.4%, respectively). Multidrug resistance was observed in 31.3% of the isolates, being higher in E. coli isolates from water (45.5%) compared to RTE street food isolates (19.2%). Virulence genes were detected in 73% of the multidrug-resistant isolates. Concerning antibiotic-resistant genes, ESBL was the most frequent (57.7%) among β-lactamases while tetA was the most frequent (50%) among non-β-lactamases.

Molecular Epidemiology of Extended-Spectrum Beta-Lactamase and AmpC Producing Enterobacteriaceae among Sepsis Patients in Ethiopia: A Prospective Multicenter Study

Extended-spectrum beta-lactamases (ESBLs) and AmpC producing Enterobacteriaceae are public health threats. This study aims to characterize ESBL and AmpC producing Enterobacteriaceae isolated from sepsis patients. A multicenter study was conducted at four hospitals located in central (Tikur Anbessa and Yekatit 12), southern (Hawassa) and northern (Dessie) parts of Ethiopia. Blood culture was performed among 1416 sepsis patients. Enterobacteriaceae (n = 301) were confirmed using MALDI-TOF and subjected for whole genome sequencing using the Illumina (HiSeq 2500) system. The overall genotypic frequencies of ESBL and AmpC producing Enterobacteriaceae were 75.5% and 14%, respectively. The detection of ESBL producing Enterobacteriaceae at Hawassa, Yekatit 12, Tikur Anbessa and Dessie was 95%, 90%, 82% and 55.8%, respectively. The detection frequency of bla_CTX-M, bla_TEM and bla_SHV genes was 73%, 63% and 33%, respectively. The most frequently detected ESBL gene was bla_CTX-M-15 (70.4%). The common AmpC genes were bla_ACT (n = 22) and bla_CMY (n = 13). Of Enterobacteriaceae that harbored AmpC (n = 42), 71% were ESBL co-producers. Both bla_TEM-1B (61.5%) and bla_SHV-187 (27.6%) were the most frequently detected variants of bla_TEM and bla_SHV, respectively. The molecular epidemiology of ESBL producing Enterobacteriaceae showed high frequencies and several variants of ESBL and AmpC genes. Good antimicrobial stewardship and standard bacteriological laboratory services are necessary for the effective treatment of ESBL producing Enterobacteriaceae.

Global surveillance of antimicrobial resistance and hypervirulence in Klebsiella pneumoniae from LMICs: An in-silico approach

The global emergence of antimicrobial resistance (AMR) among pathogens is a major public health crisis that might soon lead to a post-antibiotic era. Klebsiella pneumoniae, included in the World Health Organization list of critical priority pathogens, is an emerging threat to global health owing to the rapid rise of convergent AMR and hypervirulent strains. Comprehensive epidemiology of AMR-hypervirulent determinants in K. pneumoniae from Low-and Middle-Income Countries (LMICs) is still lacking. As part of rapid risk assessment, an in-silico approach was employed to characterize the AMR and hypervirulence determinants in K. pneumoniae from LMICs. Genomic data of 2432 K. pneumoniae strains were obtained from 33 LMICs representing 4 continents; Asia (n = 12), Africa (n = 18), N. America (n = 2) and Europe (n = 1). All the analysed strains were multiple-drug resistant and 13.6% of them were hypervirulent as well. The co-existence of antibiotic resistant genes conferring concomitant resistance towards life-saving drugs (carbapenems, colistin, fluoroquinolones and fosfomycin) were also observed among the strains, thereby challenging the efficacy of current treatment strategies. The emergence of convergent strains of K. pneumoniae carrying both multi-drug resistance and hypervirulence-associated genes in 12 LMICs is highlighted in this study. Asian region was identified as the major hotspot for convergent strains, especially being confined to 3 countries (India, Pakistan and Vietnam), further exacerbating the situation. This represents a major challenge to disease treatment and public health management in the LMICs. Regular surveillance for emergence of convergence and necessary interventions in the high-risk regions are strongly recommended.

High prevalence of multiple antibiotic resistance in clinical E. coli isolates from Bangladesh and prediction of molecular resistance determinants using WGS of an XDR isolate

Multi-drug-resistance (MDR) is a severe public health concern worldwide, and its containment is more challenging in developing countries due to poor antimicrobial resistance (AMR) surveillance and irrational use of antibiotics. The current study investigated 100 clinical E. coli isolates and revealed that 98% of them were MDR. PCR analysis using 25 selected isolates showed the predominance of metallo-β-lactamase gene bla_NDM (80%) and ESBL genes bla_OXA (48%) and bla_CTX-M-15 (32%). The AmpC gene was detected in 68% of the isolates, while 32% was tetC positive. Notably, 34% of the isolates were resistant to carbapenem. Whole genome sequence (WGS) analysis of an extensively drug-resistant (XDR) isolate (L16) revealed the presence of the notorious sequence type 131 responsible for multi-drug-resistant infections, multiple antibiotic resistance genes (ARGs), virulence genes, and mobile genetic elements that pose risks to environmental transmission. Our results indicate that MDR is alarmingly increasing in Bangladesh that critically limits the treatment option against infections and contributes to further aggravation to the prevailing situation of MDR worldwide. The findings of this study will be valuable in designing sustainable strategies to contain MDR in the region.

Molecular epidemiology of extended-spectrum beta-lactamase-producing extra-intestinal pathogenic Escherichia coli strains over a 2-year period (2017-2019) from Zimbabwe

This study was designed to characterize extended-spectrum beta-lactamase (ESBL)-producing extra-intestinal pathogenic Escherichia coli (E.coli) (ExPEC) associated with urinary tract infections in nine different geographic regions of Zimbabwe over a 2-year period (2017-2019). A total of 48 ESBL-positive isolates from urine specimen were selected for whole-genome sequencing from 1246 Escherichia coli isolates biobanked at the National Microbiology Reference laboratory using phenotypic susceptibility testing results from the National Escherichia coli Surveillance Programme to provide representation of different geographical regions and year of isolation. The majority of ESBL E. coli isolates produced cefotaximase-Munich (CTX-M)-15, CTX-M-27, and CTX-M-14. In this study, sequence types (ST) 131 and ST410 were the most predominant antimicrobial-resistant clones and responsible for the increase in ESBL-producing E. coli strains since 2017. Novel ST131 complex strains were recorded during the period 2017 to 2018, thus showing the establishment and evolution of this antimicrobial-resistant ESBL clone in Zimbabwe posing an important public health threat. Incompatibility group F plasmids were predominant among ST131 and ST410 isolates with the following replicons recorded most frequently: F1:A2:B20 (9/19, 47%), F2:A1: B (5/19, 26%), and F1:A1:B49 (8/13, 62%). The results indicate the need for continuous tracking of different ESBL ExPEC clones on a global scale, while targeting specific STs (e.g. ST131 and ST410) through control programs will substantially decrease the spread of ESBLs among ExPEC.

Multiple sequence types, virulence determinants and antimicrobial resistance genes in multidrug- and colistin-resistant Escherichia coli from agricultural and non-agricultural soils

In soils, the presence of clinically relevant bacteria carrying ARGs, including extended-spectrum β-lactamase- and plasmid-mediated AmpC β-lactamase-encoding genes, is an underestimated public health problem that requires more attention. For this investigation, 300 samples from agricultural and non-agricultural soils were used to obtain 41 MDR E. coli isolates, standing out the resistance to β-lactams, fluoroquinolones and colistin. Virulence genes related to diarrheagenic E. coli and extraintestinal pathogenic E. coli were detected. Several ARGs were found, highlighting the presence of at least one β-lactamase-encoding gene (bla_TEM, bla_CMY, bla_SHV, bla_OXA-1-like, bla_CTX-M-2, and/or bla_CTX-M-15) in each isolate. Among the fluoroquinolone-resistant E. coli isolates, the plasmid-mediated quinolone resistance genes (qnrB and oqxA) and substitutions in the quinolone resistance-determining regions were detected. Some isolates were resistant to colistin (MICs of 4-8 mg/L) and, although no mcr-like gene was detected, substitutions in the two-component systems involving PhoP/PhoQ and PmrA/PmrB were found. Furthermore, the E. coli isolates presented plasmids and class 1 integrons, the last one detected in all isolates. The ARGs bla_TEM, aadA and dfrA and the lpfA virulence-associated gene presented statistically significant differences (P < 0.05) in agricultural soils, while the bla_OXA-1-like gene presented a statistically significant difference in non-agricultural soils. Thirty-eight sequence types (STs) were identified among the isolates, spotlighting the 20 different STs that carried bla_CMY and bla_CTX-M-type genes and those commonly reported in infections worldwide. The occurrence of virulent, multidrug- and colistin-resistant E. coli isolates in soils could lead to contamination of surrounding environments and food, increasing the risk of human and animal exposure. Therefore, this study contributes to a better understanding of E. coli in soils and reinforces the importance of the One Health approach to antimicrobial resistance surveillance.

High Fecal Contamination and High Levels of Antibiotic-Resistant Enterobacteriaceae in Water Consumed in the City of Maputo, Mozambique

Simple Summary

The high number of diarrheal disease cases in developing countries is related to sanitation conditions, consumption of untreated water, and poor individual and collective hygiene. In this study, the microbiological quality of water sold and consumed in the city of Maputo, Mozambique, and the antibiotic resistance profile of Enterobacteriaceae isolated from these samples were evaluated. The results showed the occurrence of microorganisms that indicate fecal contamination with enterococci, fecal coliforms, and Escherichia coli above the limit legally allowed for drinking water. The antibiotic resistance profile revealed the existence of antibiotic-resistant bacteria. These results show the need to improve the water supply system in the city of Maputo and to educate the population on hygiene to reduce health risks and promote well-being.

Abstract

In the city of Maputo, Mozambique, food and water are often sold on the streets. Street water is packaged, distributed, and sold not paying attention to good hygienic practices, and its consumption is often associated with the occurrence of diarrheal diseases. Coincidentally, the increase of diarrheal diseases promotes the inappropriate use of antibiotics that might cause the emergence of antibiotic-resistant bacterial strains. In this context, the present study aimed to assess the microbiological quality of water sold on the streets of Maputo, as well as the antibiotic resistance profile of selected Enterobacteriaceae isolates. The 118 water samples analyzed were from street home-bottled water (n = 81), municipal water distribution systems (tap water) (n = 25), and selected supply wells in several neighborhoods (n = 12). The samples were analyzed for total mesophilic microorganisms, fecal enterococci, fecal coliforms, Escherichia coli, and Vibrio spp. The results showed a high level of fecal contamination in all types of water samples. In home-bottled water, fecal coliforms were found in 88% of the samples, and E. coli in 66% of the samples. In tap water, fecal coliforms were found in 64%, and E. coli in 28% of the samples. In water from supply wells, fecal coliforms and E. coli were found in 83% of the samples. From 33 presumptive Vibrio spp. colonies, only three were identified as V. fluvialis. The remaining isolates belonged to Aeromonas spp. (n = 14) and Klebsiella spp. (n = 16). Of 44 selected Enterobacteriaceae isolates from water samples (28 isolates of E. coli and 16 isolates of Klebsiella spp.), 45.5% were not susceptible to the beta-lactams ampicillin and imipenem, 43.2% to amoxicillin, and 31.8% to amoxicillin/clavulanic acid. Regarding non-beta-lactam antibiotics, there was a high percentage of isolates with tolerance to tetracycline (52.3%) and azithromycin (31.8%). In conclusion, water in Maputo represents a risk for human health due to its high fecal contamination. This situation is made more serious by the fact that a relatively high percentage of isolates with multidrug resistance (40%) were found among Enterobacteriaceae. The dissemination of these results can raise awareness of the urgent need to reduce water contamination in Maputo and other cities in Mozambique.