Household cockroaches carry CTX-M-15-, OXA-48- and NDM-1-producing enterobacteria, and share beta-lactam resistance determinants with humans

Carbapenem-Resistant NDM and OXA-48-like Producing K. pneumoniae: From Menacing Superbug to a Mundane Bacteria; A Retrospective Study in a Romanian Tertiary Hospital

BACKGROUND

Carbapenem-resistant Klebsiella pneumoniae (Cr-Kpn) is becoming a growing public health problem through the failure of adequate treatment. This study's objectives are to describe the sources of Cr-Kpn in our hospital over 22 months, associating factors with the outcome of Cr-Kpn-positive patients, especially those with NDM+OXA-48-like (New Delhi Metallo-β-Lactamase and oxacillinase-48), and the effectiveness of the treatments used.

METHODS

A retrospective observational cohort study including all hospitalized patients with Cr-Kpn isolates. We reported data as percentages and identified independent predictors for mortality over hospital time through multivariate analysis.

RESULTS

The main type of carbapenemases identified were NDM+OXA-48-like (49.4%). The statistical analysis identified that diabetes and co-infections with the Gram-negative, non-urinary sites of infection were factors of unfavorable evolution. The Cox regression model identified factors associated with a poor outcome: ICU admission (HR of 2.38), previous medical wards transition (HR of 4.69), and carbapenemase type NDM (HR of 5.98). We did not find the superiority of an antibiotic regimen, especially in the case of NDM+OXA-48-like.

CONCLUSIONS

The increase in the incidence of Cr-Kpn infections, especially with NDM+OXA-48-like pathogens, requires a paradigm shift in both the treatment of infected patients and the control of the spread of these pathogens, which calls for a change in public health policy regarding the use of antibiotics and the pursuit of a One Health approach.

Extended-spectrum beta-lactamases in clinical isolates of Escherichia coli and Klebsiella pneumoniae recovered from patients at the Tamale Teaching Hospital, Ghana

INTRODUCTION

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae are pathogens of significant public health interest for which new antibiotics are urgently needed.

AIM

To determine the prevalence of ESBLs in E. coli and K. pneumoniae isolates from patients attending the Tamale Teaching Hospital (TTH) in Ghana.

METHODOLOGY

The study was a cross-sectional study involving convenience sampling of E. coli and K. pneumoniae isolates from consenting patients' clinical specimens, between April and June 2015. Antimicrobial susceptibility test was performed, and ESBL-producer phenotypes were further screened for BlaTEM, BlaSHV, and BlaCTX-M genes. Patients' clinical data were additionally collected using a structured questionnaire.

RESULTS

Of the 150 non-duplicate E. coli and K. pneumoniae isolates identified, 140 were confirmed as E. coli (84%, n = 117) and K. pneumoniae (16%, n = 23). Of these, sixty-two (44%) [E. coli (84%; n = 52); K. pneumoniae (16%; n = 10)] phenotypically expressed ESBLs. The proportion of ESBL-producing isolates was higher in adults (15-65 years) than in neonates (< 28 days) (p = 0.14). Most of the isolates showed a high percentage resistance to ampicillin (96%) and tetracycline (89%), but a relatively lower resistance to amikacin (36%). No isolate was resistant to meropenem. More ESBL producers were multidrug resistant compared to non-ESBL-producers [23% (14/62) versus 18% (14/78); p = 0.573]. Overall, 74% (n = 46) of the ESBL genotypes expressed BlaCTX-M-1 genes, followed by 63% (n = 39) BlaTEM, and 16% (n = 10) BlaSHV. The study showed a high prevalence of ESBL-positive E. coli and K. pneumoniae, mostly CTX-M-1 producers at TTH.

CONCLUSION

Routine laboratory ESBL screening is warranted to inform patient management.

Cross-sectional analysis of risk factors associated with Mugil cephalus in retail fish markets concerning methicillin-resistant Staphylococcus aureus and Aeromonas hydrophila

Introduction

Aeromonas hydrophila and methicillin-resistant Staphylococcus aureus (MRSA) are potent bacterial pathogens posing major hazards to human health via consuming fish harboring these pathogens or by cross-contamination beyond the contaminated environment. The aim of this study was to determine risk variables associated with the presence of certain pathogenic bacteria from Mugil cephalus fish in retail markets in Egypt. The virulence genes of A. hydrophila and S. aureus were also studied. Furthermore, the antibiotic sensitivity and multidrug resistance of the microorganisms were evaluated.

Methods

In a cross-sectional investigation, 370 samples were collected from mullet skin and muscle samples, washing water, fish handlers, knives, and chopping boards. Furthermore, fish handlers' public health implications were assessed via their response to a descriptive questionnaire.

Results

S. aureus and Aeromonas species dominated the investigated samples with percentages of 26.76% and 30.81%, respectively. Furthermore, A. hydrophila and MRSA were the predominant recovered bacterial pathogens among washing water and knives (53.85% and 46.66%, respectively). The virulence markers aerA and hlyA were found in 90.7% and 46.5% of A. hydrophila isolates, respectively. Moreover, the virulence genes nuc and mec were prevalent in 80% and 60% of S. aureus isolates, respectively. Antimicrobial susceptibility results revealed that all A. hydrophila isolates were resistant to amoxicillin and all MRSA isolates were resistant to amoxicillin and ampicillin. Remarkably, multiple drug resistance (MDR) patterns were detected in high proportions in A. hydrophila (88.37%) and MRSA (100%) isolates. The prevalence of Aeromonas spp. and S. aureus had a positive significant correlation with the frequency of handwashing and use of sanitizer in cleaning of instruments. MRSA showed the highest significant prevalence rate in the oldest age category.

Conclusion

The pathogenic bacteria recovered in this study were virulent and had a significant correlation with risk factors associated with improper fish handling. Furthermore, a high frequency of MDR was detected in these pathogenic bacteria, posing a significant risk to food safety and public health.

Screening for Resistant Bacteria, Antimicrobial Resistance Genes, Sexually Transmitted Infections and Schistosoma spp. in Tissue Samples from Predominantly Vaginally Delivered Placentae in Ivory Coast and Ghana

Medical complications during pregnancy have been frequently reported from Western Africa with a particular importance of infectious complications. Placental tissue can either become the target of infectious agents itself, such as, e.g., in the case of urogenital schistosomiasis, or be subjected to contamination with colonizing or infection-associated microorganisms of the cervix or the vagina during vaginal delivery. In the retrospective cross-sectional assessment presented here, the quantitative dimension of infection or colonization with selected resistant or pathogenic bacteria and parasites was regionally assessed. To do so, 274 collected placental tissues from Ivory Coastal and Ghanaian women were subjected to selective growth of resistant bacteria, as well as to molecular screening for beta-lactamase genes, Schistosoma spp. and selected bacterial causative agents of sexually transmitted infections (STI). Panton-Valentine-negative methicillin-resistant Staphylococcus aureus (MRSA) was grown from 1.8% of the tissue samples, comprising the spa types t008 and t688, as well as the newly detected ones, t12101 (n = 2) and t12102. While the culture-based recovery of resistant Enterobacterales and nonfermentative rod-shaped Gram-negative bacteria failed, molecular assessments confirmed beta-lactamase genes in 31.0% of the samples with multiple detections of up to four resistance genes per sample and blaCTX-M, blaIMP, blaGES, blaVIM, blaOXA-58-like, blaNDM, blaOXA-23-like, blaOXA-48-like and blaKPC occurring in descending order of frequency. The beta-lactamase genes blaOXA-40/24-like, blaNMC_A/IMI, blaBIC, blaSME, blaGIM and blaDIM were not detected. DNA of the urogenital schistosomiasis-associated Schistosoma haematobium complex was recorded in 18.6% of the samples, but only a single positive signal for S. mansoni with a high cycle-threshold value in real-time PCR was found. Of note, higher rates of schistosomiasis were observed in Ghana (54.9% vs. 10.3% in Ivory Coast) and Cesarean section was much more frequent in schistosomiasis patients (61.9% vs. 14.8% in women without Schistosoma spp. DNA in the placenta). Nucleic acid sequences of nonlymphogranuloma-venereum-associated Chlamydia trachomatis and of Neisseria gonorrhoeae were recorded in 1.1% and 1.9% of the samples, respectively, while molecular attempts to diagnose Treponema pallidum and Mycoplasma genitalium did not lead to positive results. Molecular detection of Schistosoma spp. or STI-associated pathogens was only exceptionally associated with multiple resistance gene detections in the same sample, suggesting epidemiological distinctness. In conclusion, the assessment confirmed considerable prevalence of urogenital schistosomiasis and resistant bacterial colonization, as well as a regionally expected abundance of STI-associated pathogens. Continuous screening offers seem advisable to minimize the risks for the pregnant women and their newborns.

Occurrence of High-Risk Clonal Lineages ST58, ST69, ST224, and ST410 among Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolated from Healthy Free-Range Chickens (Gallus gallus domesticus) in a Rural Region in Tunisia

Antimicrobial-resistant Escherichia coli isolates have emerged in various ecologic compartments and evolved to spread globally. We sought to (1.) investigate the occurrence of ESBL-producing E. coli (ESBL-Ec) in feces from free-range chickens in a rural region and (2.) characterize the genetic background of antimicrobial resistance and the genetic relatedness of collected isolates. Ninety-five feces swabs from free-range chickens associated with two households (House 1/House 2) in a rural region in northern Tunisia were collected. Samples were screened to recover ESBL-Ec, and collected isolates were characterized for phenotype/genotype of antimicrobial resistance, integrons, and molecular typing (pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST)). Overall, 47 ESBL-Ec were identified, with the following genes detected: 35 bla_CTX-M-1, 5 bla_CTX-M-55, 5 bla_CTX-M-15, 1 bla_SHV-2, and 1 bla_SHV-12. Resistance to fluoroquinolones, tetracycline, sulfonamides, and colistin was encoded by aac(6')-Ib-cr (n = 21), qnrB (n = 1), and qnrS (n = 2); tetA (n = 17)/tetB (n = 26); sul1 (n = 29)/sul2 (n = 18); and mcr-2 (n = 2) genes, respectively. PFGE and MLST identified genetic homogeneity of isolates in House 1; however, isolates from House 2 were heterogeneous. Notably, among nine identified sequence types, ST58, ST69, ST224, and ST410 belong to pandemic high-risk clonal lineages associated with extrapathogenic E. coli. Minor clones belonging to ST410 and ST471 were shared by chickens from both households. The virulence genes fyuA, fimH, papGIII, and iutA were detected in 35, 47, 17, and 23 isolates, respectively. Findings indicate a high occurrence of ESBL-Ec in free-range chickens and highlight the occurrence of pandemic zoonotic clones.

Assessment of pre-eclampsia and eclampsia health commodities’ supply chains in selected hospitals of Lagos State during COVID-19 pandemic

Purpose

Pre-eclampsia and eclampsia (PE/E) are rising in Sub-Saharan Africa, including Nigeria. This study aims to evaluate the availability and logistics management of sixteen items from the Nigerian essential medicine list required for managing these conditions.

Design/Methodology/approach

A cross-sectional study in 50 health-care facilities in Lagos State, Nigeria, at the beginning of the COVID-19 pandemic by interviewing the facility’s main person in charge of health commodities. Data were recorded during the visit and in the previous six months using the adapted Logistics Indicators Assessment Tool (LIAT). In addition, descriptive analysis was conducted based on the World Health Organization availability index.

Findings

The availability of 13 (81%) of the commodities were high, and 3 (19%) were relatively high in the facilities, stock out rate during the visitation and previous six months varied with the commodities: urinalysis strip (22%) and (40%), hydralazine (20%) and (20%), labetalol injection (8%) and (20%), labetalol tablet (24%) and (24%) and sphygmomanometer (8%) and (8%). No stock out was recorded for 11 (69%) commodities. All the facilities observed 9 (75%) out of the 12 storage guidelines, and 36 (72%) had a perfect storage condition score.

Limitations/Implications

Current state of PE/E health commodities in the selected facilities is highlighted, and the strengths and weaknesses of the supply chain in these health facilities were identified and discussed.

Originality/value

These commodities’ availability ranged from reasonably high to very high. Regular supportive supervision is germane to strengthening the logistics management system for these commodities to prevent the negative impact on the health and well-being of the people during the COVID-19 pandemic and post-pandemic.

Understanding the role of insects in the acquisition and transmission of antibiotic resistance

Antibiotic resistance (AR) is a global healthcare threat that requires a comprehensive assessment. Poorly regulated antibiotic stewardship in clinical and non-clinical settings has led to a horizontal dissemination of AR. A variety of often neglected elements facilitate the circulation of AR from antibiotic sinks like concentrated animal feeding operations and healthcare settings to other environments that include healthy human communities. Insects are one of those elements that have received underwhelming attention as vectors of AR, despite their well-known role in transmitting clinically relevant pathogens. We here make an exhaustive attempt to highlight the role of insects as zoonotic reservoirs of AR by discussing the available literature and deriving realistic inferences. We review the AR associated with insects housing various human-relevant environments, namely, animal farm industry, edible-insects enterprise, healthcare institutes, human settlements, agriculture settings and the wild. We also provide evidence-based accounts of the events of the transmission of AR from insects to humans. We evaluate the clinical threats associated with insect-derived AR and propose the adoption of more sophisticated strategies to understand and mitigate future AR concerns facilitated by insects. Future works include a pan-region assessment of insects for AR in the form of AR bacteria (ARB) and AR determinants (ARDs) and the introduction of modern techniques like whole-genome sequencing, metagenomics, and in-silico modelling.

Phenotypic and genotypic detection of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in Accra, Ghana

AIM

To describe the occurrence of carbapenem resistance among multidrug-resistant (MDR) Escherichia coli and Klebsiella pneumoniae isolated from clinical specimens in Accra using phenotypic and genotypic methods.

METHODOLOGY

The study was cross-sectional, involving 144 clinical MDR E. coli and K. pneumoniae isolates recovered from the Central Laboratory of the Korle Bu Teaching Hospital (KBTH). The isolates were re-cultured bacteriologically, identified using standard biochemical tests, and subjected to antibiotic susceptibility testing using the Kirby-Bauer method. Carbapenem resistance was determined based on imipenem, meropenem, and ertapenem zones of inhibition, as well as minimum inhibitory concentrations (MICs). Carbapenemase production was determined phenotypically by modified Hodge test (MHT) and modified carbapenem inactivation method (mCIM), and genotypically with multiplex PCR targeting the blaKPC, blaIMP, blaNDM, blaVIM, and blaOXA-48 genes.

RESULTS

Of the 144 MDR isolates, 69.4% were E. coli, and 30.6% were K. pneumoniae. The distribution of antimicrobial resistance rates among them was ampicillin (97.2%), cefuroxime (93.1%), sulfamethoxazole-trimethoprim (86.8%), tetracycline (85.4%), cefotaxime and cefpodoxime (77.1% each), amoxicillin-clavulanate (75%), ceftriaxone (73.6%), ciprofloxacin (70.8%), levofloxacin (66.0%), cefepime (65.3%), ceftazidime (64.6%), gentamicin (48.6), piperacillin-tazobactam (40.3%), cefoxitin (14.6%), amikacin (13.9%), ertapenem and meropenem (5.6% each), and imipenem (2.8%). In total, 5.6% (8/144) of them were carbapenem-resistant (carbapenem MIC range = 0.094-32.0 μg/ml), with 75% (6/8) of these testing positive by the phenotypic tests and 62.5% (5/8) by the genotypic test (of which 80% [4/5] carried blaOXA-48 and 20% (1/5) blaNDM). The blaVIM, blaIMP, and blaKPC genes were not detected.

CONCLUSION

Although the rates of antibiotic resistance among the isolates were high, the prevalence of carbapenemase producers was low. The finding of blaOXA-48 and blaNDM warrants upscaling of antimicrobial resistance surveillance programmes and fortification of infection prevention and control programmes in the country.

Multidrug-Resistant Gram-Negative Bacteria Contaminating Raw Meat Sold in Accra, Ghana

BACKGROUND

Efforts to combat antimicrobial resistance (AMR) should be based on the One Health approach, involving human health, animal health, and the environment. In Ghana, previous studies on AMR have given little attention to animal source food, a major route of transmission of antibiotic-resistant zoonotic pathogens. The aim of this study was to investigate the occurrence of multidrug-resistant (MDR) bacteria in meat sold in Accra.

METHODS

This was a cross-sectional study in which 270 meat samples (90 each of beef, goat meat, and chicken) were collected, and investigated for contamination with multidrug-resistant bacteria. The bacteria were subjected to susceptibility testing against amikacin (30 µg), ampicillin (10 µg), amoxicillin-clavulanate (20/10 µg), cefuroxime (30 µg), ceftriaxone (30 µg), ceftazidime (30 µg), cefepime (30 µg), ciprofloxacin (5 µg), trimethoprim-sulfamethoxazole (1.25/23.75 µg), ertapenem (10 µg), meropenem (10 µg), imipenem (10 µg), tigecycline (15 µg), and gentamicin (10 µg).

RESULTS

Thirty-two different types of bacteria, totalling 558, were isolated, the predominant being Escherichia coli (44.6%), Aeromonas hydrophila (19.9%), Vibrio cholerae (3.4%), Aeromonas veronii (3.2%), and Klebsiella pneumoniae (3.1%). The prevalence of MDR among the contaminating bacteria was 14.9%. The MDR distribution among the predominant bacteria was Escherichia coli (18.7%), Aeromonas hydrophila (11.1%), Vibrio cholerae and Aeromonas veronii (0.0% each), and K. pneumoniae (5.6%). Moreover, 2.0% of the contaminating bacteria were extended-spectrum beta-lactamase (ESBL) producers, all of which occurred in the chicken samples, and their distribution was: Escherichia coli (1.3%), Klebsiella pneumoniae, Pantoea spp., Enterobacter cloacae, and Serratia plymuthica (0.2% each).

CONCLUSIONS

The meat samples were heavily contaminated with Escherichia coli and Aeromonas hydrophila, and less frequently, with Vibrio cholerae, Klebsiella pneumoniae, and other organisms. The prevalence of multidrug-resistant bacteria was moderate (14.9%), while that of ESBL producers was low (2%).

Occurrence and significance of fluoroquinolone-resistant and ESBL-producing Escherichia coli and Klebsiella pneumoniae complex of the rectal flora in Ghanaian patients undergoing prostate biopsy

Background

Reports suggest that fluoroquinolone (FQ)-resistant and ESBL-producing rectal flora are associated with infectious complications in men undergoing transrectal ultrasound-guided prostate needle biopsy (TRUS-B)

Objectives

We investigated the relationship between carriage of FQ-resistant and ESBL-producing Escherichia coli and Klebsiella pneumoniae complex of the rectal flora, and the 30 day incidence rate of post-TRUS-B infectious complications.

Methods

From 1 January 2018 to 30 April 2019, rectal swabs of 361 patients were cultured pre-TRUS-B for FQ-resistant and ESBL-producing flora. Patients were followed up for 30 days for infectious complications post-biopsy. Multivariable logistic regression analyses were used to identify risk factors.

Results

Overall, 86.4% (n = 312/361) and 62.6% (n = 226/361) of patients carried FQ-resistant and ESBL-producing E. coli and K. pneumoniae complex, respectively. Approximately 60% (n = 289/483) of the FQ-resistant and 66.0% (n = 202/306) of the ESBL-positive isolates exhibited in vitro resistance to the pre-biopsy prophylactic antibiotic regimen of levofloxacin and gentamicin. Amikacin and meropenem were the most effective antibiotics against the MDR rectal E. coli and K. pneumoniae complex (78.7% and 84.3%, respectively). The 30 day incidence rate for post-biopsy infections was 3.1% (n = 11/361), with an overall high probability (96.9%) of staying free of infections within the 30 day period post-TRUS-B. Antibiotic use in the previous 3 months was a risk factor for rectal carriage of FQ-resistant and ESBL-positive isolates. Rectal colonization by ESBL-positive E. coli and K. pneumoniae complex comprised an independent risk factor for post-biopsy infectious complications.

Conclusions

The findings suggest that a change in prophylactic antibiotics to a more targeted regimen may be warranted in our institution.

Multidrug-Resistant Bacteria in Hospital Wastewater of the Korle Bu Teaching Hospital in Accra, Ghana

BACKGROUND

Antimicrobial resistance (AMR) is one of the top 10 public health threats. One approach to tackling the AMR menace could involve expanding the range of AMR surveillance domains to include hospital wastewater (HWW), a domain that has largely been overlooked by researchers.

AIM

To evaluate the occurrence of multidrug-resistant bacteria in hospital wastewater of the Korle Bu Teaching Hospital (KBTH).

METHODOLOGY

This was a longitudinal study involving 288 HWW samples consecutively collected across 12 weeks from the pool of wastewater emanating from 2 critical care units of KBTH-The Child Health Unit and the Maternity Unit-on Mondays and Thursdays, each week. The samples were cultured for bacteria, which were identified using the Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) technique and subjected to antimicrobial susceptibility testing via the Kirby-Bauer method.

RESULTS

In total, 294 bacteria of 23 different types, all being Gram-negative, were isolated from the 288 samples. The predominant ones were Escherichia coli (30.6%, n = 90), Klebsiella pneumoniae (11.2%, n = 33), Citrobacter freundii (10.9%, n = 32), Alcaligenes faecalis (5.8%, n = 17), and Pseudomonas mendocina (5.4%, n = 16). The prevalence of multidrug resistance among the isolates was 55.4% (n = 163). Moreover, the prevalence of extended-spectrum beta-lactamase (ESBL) producers was 15.6% (n = 46). E. coli accounted for the most ESBL-producing organisms (28.9%, n = 26).

CONCLUSION

The wastewater generated by the Maternity and Child Health Units of KBTH harbored a wide range of multidrug resistant bacteria, with a good proportion of these being ESBL producers, and the predominant one being E. coli. The study thus identifies the wastewater of KBTH as an important source of multidrug resistant organisms, and underscores the significance of appropriate treatment of wastewater of the hospital and other clinical, and related settings prior to its discharge.

Dissemination of OXA-48- and NDM-1-Producing Enterobacterales Isolates in an Algerian Hospital

Multidrug-resistant (MDR) Enterobacterales remain an increasing problem in Algeria, notably due to the emergence of carbapenemase producers. We investigated the molecular characteristics of carbapenem-resistant Enterobacterales isolates recovered from outpatients and inpatients in Eastern Algeria. Non-repetitive Enterobacterales with reduced susceptibility to carbapenems were consecutively collected from clinical specimens in Annaba University Hospital (Algeria) between April 2016 and December 2018. Isolates were characterized with regard to antibiotic resistance, resistome and virulome content, clonality, and plasmid support. Of the 168 isolates analyzed, 29 (17.3%) were carbapenemase producers and identified as K. pneumoniae (n = 23), E. coli (n = 5), and E. cloacae (n = 1). bla_OXA-48 was the most prevalent carbapenemase-encoding gene (n = 26/29), followed by bla_NDM-1 gene (n = 3/29). K. pneumoniae isolates harbored some virulence traits (entB, ugeF, ureA, mrkD, fimH), whereas E. coli had a commensal origin (E, A, and B1). Clonality analysis revealed clonal expansions of ST101 K. pneumoniae and ST758 E. coli. Plasmid analysis showed a large diversity of incompatibility groups, with a predominance of IncM (n = 26, 89.7%). A global dissemination of OXA-48-producing Enterobacterales in the Algerian hospital but also the detection of NDM-1-producing E. coli in community settings were observed. The importance of this diffusion must be absolutely investigated and controlled.

Diarrhea-Causing Bacteria and Their Antibiotic Resistance Patterns Among Diarrhea Patients From Ghana

Diarrheal disease remains a major global health problem particularly in children under 5 years and the emergence of antibiotic-resistant strains of causative pathogens could slow control efforts, particularly in settings where treatment options are limited. This surveillance study conducted in Ghana aimed to determine the prevalence and antimicrobial susceptibility profile of diarrhea-causing bacteria. This was a cross-sectional study carried out in five health facilities in the Ga West Municipality of Ghana between 2017 and 2021. Diarrheic stool samples from patients were collected and cultured on standard differential/selective media and isolates identified by standard biochemical tests, MALDI-TOF assay, and serological analysis. The antibiogram was determined using Kirby-Bauer disk diffusion and Microscan autoScan4 MIC panels which were used for extended-spectrum beta-lactamase (ESBL) detection. Bacteria were isolated from 97.5% (772/792) of stool samples, and 167 of the isolates were diarrheagenic and met our inclusion criteria for antimicrobial resistance (AMR) analysis. These included Escherichia coli (49.1%, 82/167), Salmonella species (23.9%, 40/167), Vibrio species (16.8%, 28/167), and Shigella species (10.2%, 17/167). Among 24 Vibrio species, we observed resistances to cefotaxime (21/24, 87.5%), ceftriaxone (20/24, 83.3%), and ciprofloxacin (6/24, 25%), including four multi-drug resistant isolates. All 13 Vibrio parahaemolyticus isolates were resistant to cefazolin. All 17 Shigella isolates were resistant to tetracycline with resistance to shigellosis drugs such as norfloxacin and ciprofloxacin. Salmonella isolates were highly susceptible to norfloxacin (40/40, 100%) and tetracycline (12/34, 35%). Two ESBL-producing E. coli were also identified with marked susceptibility to gentamicin (66/72, 91.7%) and amikacin (57/72, 79.2%) prescribed in the treatment of E. coli infections. This study showed the different bacteria implicated in diarrhea cases in Ghana and the need for differential diagnoses for better treatment outcomes. Escherichia coli, Shigella, Salmonella, and Vibrio have all been implicated in diarrhea cases in Ghana. The highest prevalence was E. coli and Salmonella with Shigella the least prevalent. Resistance to commonly used drugs found in these isolates may render bacteria infection treatment in the near future nearly impossible. Routine antimicrobial susceptibility testing, effective monitoring, and nationwide surveillance of AMR pathogens should be implemented to curb the increase of antimicrobial resistance in Ghana.

First Report of Extended-Spectrum β-Lactamase (blaCTX-M1) and Colistin Resistance Gene mcr-1 in E. coli of Lineage ST648 from Cockroaches in Tunisia

The emergence of multidrug-resistant bacteria has become a major problem. Cockroaches may play an important role in the spread of those bacteria between the environment and humans. This study was designed to screen extended-spectrum β-lactamase (ESBL)-producing and colistin-resistant strains and to investigate the molecular support of multidrug-resistant Enterobacteriaceae in the external surface and gut homogenates of cockroaches collected from different locations in Tunisia. Between July 2017 and June 2018, 144 Enterobacteriaceae samples were isolated from 115 trapped cockroaches (collective catering, houses, and a hospital). Antibiotic susceptibility testing was performed using the disk diffusion method. Extended-spectrum β-lactamase-encoding genes and the mcr-1 gene were investigated by real-time PCR (RT-PCR) and standard PCR. The genetic relationship among isolates was studied with the help of multilocus sequence type (MLST) analysis. Of the 144 Enterobacteriaceae isolates, 22 strains exhibited a positive ESBL-screening test (73.3%), including 17 Escherichia coli isolates and 5 Klebsiella pneumoniae isolates. Among them, 9 Escherichia coli isolates were resistant to colistin, with an MIC ranging from 8 to16 μg/L, all of which harbored the mcr-1 gene. Eight bla_CTX-M-15 genes were detected; two among them were associated with bla_TEM-117 and bla_TEM-128, and seven bla_CTX-M-1 genes were detected that also harbored the mcr-1 gene. Genotyping analysis revealed 7 different sequence types already described in humans and animals. We report the first survey of mcr-1 in ESBL-producing E. coli isolates from cockroaches. Our findings highlight cockroaches as a source of nosocomial infections, and they are a reservoir of colistin-resistant E. coli, which is a carrier of other additional risk genes such as bla_ESBL, especially in hospitals.

IMPORTANCE Multidrug resistance in Enterobacteriaceae has become a major concern worldwide that is increasingly observed in human, animals, and also cockroaches. In our study, we found that cockroaches may play an important role as a potential vector of multidrug-resistant Enterobacteriaceae in the hospital environment and collective catering. Our study describes the first survey of mcr-1 in ESBL-producing E. coli isolates from hospital cockroaches. Our results further highlight the possibility that mcr-1 may enter humans via cockroach contamination and thereby threaten public health. Our results show that these cockroaches are an important reservoir of colistin-resistant E. coli and carriers of other additional risk genes such as bla_ESBL, hence the importance of strengthening prevention strategies and of strictly respecting hygiene measures in order to control their distribution and spread in Tunisia.

New insight into the relationship between Salmonella Typhimurium and the German cockroach suggests active mechanisms of vector-borne transmission

Diarrheal diseases are among the most common illnesses in the world and the bacterium Salmonella enterica serovar Typhimurium is a leading cause of morbidity and mortality from diarrhea globally. The German cockroach (Blattella germanica) frequently harbors and has been linked to human outbreaks of Salmonella, but the mechanisms of vector-borne transmission are not fully clear. Transmission of S. Typhimurium by cockroaches has been previously described as mechanical. Mechanical transmission is a wholly passive process that involves physical transfer of a pathogen from one location or host to another but lacks bacterial replication in the vector and active bacterial processes that promote vector colonization or transmission. Towards the goal of obtaining novel insight into the mechanisms of S. Typhimurium transmission by cockroaches, here we orally provisioned wild type and mutant strains of the bacteria to adult B. germanica and examined several aspects of colonization and shedding. Our results provide evidence of three previously unappreciated phenomena with significant implications. First, we demonstrate that S. Typhimurium undergoes replication at multiple phases during colonization of the cockroach gut. Second, we show the formation of biofilm-like aggregates by S. Typhimurium in the cockroach foregut. Lastly, we identify two mutant strains of S. Typhimurium that are deficient in colonization and shedding relative to isogenic controls, implicating type III secretion and the formation of fimbriae as two processes that are necessary for interaction with the cockroach vector. Together, our data indicate that transmission of S. Typhimurium by cockroaches is not solely mechanical but may resemble biological transmission by other insect vectors that intake human pathogenic bacteria from infected hosts and are subsequently colonized, enabling active dissemination. Thus, these findings suggest that cockroaches and their control may be more important for infection prevention than is currently appreciated. Additional studies to better understand the cycle and biological mechanisms of vector-borne transmission are warranted.

A role for arthropods as vectors of multidrug-resistant Enterobacterales in surgical site infections from South Asia

Understanding how multidrug-resistant Enterobacterales (MDRE) are transmitted in low- and middle-income countries (LMICs) is critical for implementing robust policies to curb the increasing burden of antimicrobial resistance (AMR). Here, we analysed samples from surgical site infections (SSIs), hospital surfaces (HSs) and arthropods (summer and winter 2016) to investigate the incidence and transmission of MDRE in a public hospital in Pakistan. We investigated Enterobacterales containing resistance genes (bla_CTX-M-15, bla_NDM and bla_OXA-48-like) for identification, antimicrobial susceptibility testing and whole-genome sequencing. Genotypes, phylogenetic relationships and transmission events for isolates from different sources were investigated using single-nucleotide polymorphism (SNP) analysis with a cut-off of ≤20 SNPs. Escherichia coli (14.3%), Klebsiella pneumoniae (10.9%) and Enterobacter cloacae (16.3%) were the main MDRE species isolated. The carbapenemase gene bla_NDM was most commonly detected, with 15.5%, 15.1% and 13.3% of samples positive in SSIs, HSs and arthropods, respectively. SNP (≤20) and spatiotemporal analysis revealed linkages in bacteria between SSIs, HSs and arthropods supporting the One Health approach to underpin infection control policies across LMICs and control AMR.

Conjugative Plasmids Disseminating CTX-M-15 among Human, Animals and the Environment in Mwanza Tanzania: A Need to Intensify One Health Approach

Background: Globally, bla_CTX-M-15 beta-lactamases are the most popular extended spectrum beta-lactamase alleles that are widely distributed due its mobilisation by mobile genetic elements in several compartments. We aimed to determine the conjugation frequencies and replicon types associated with plasmids carrying bla_CTX-M-15 gene from Extended Spectrum Beta-lactamase producing isolates in order to understand the dissemination of resistance genes in different compartments. Material and methods: A total of 51 archived isolates carrying bla_CTX-M-15 beta-lactamases were used as donors in this study. Antibiotic susceptibility tests were performed as previously described for both donors and transconjugants. Conjugation experiment was performed by a modified protocol of the plate mating experiment, and plasmid replicon types were screened among donor and transconjugant isolates by multiplex Polymerase Chain Reaction in a set of three primer panels. Results: The conjugation efficiency of plasmids carrying bla_CTX-M-15 was 88.2% (45/51) with conjugation frequencies in the order of 10⁻¹ to 10⁻⁹ and a 100% transfer efficiency observed among E. coli of animal origin. Majority of donors (n = 21) and transconjugants (n = 14) plasmids were typed as either Inc FIA or Inc FIB. Resistance to non-beta-lactam antibiotics was transferrable in 34/45 (75.6%) of events. Ciprofloxacin, tetracycline and sulphamethoxazole-trimethoprim resistance was co-transferred in 29/34 (85.3%) such events. Gentamicin resistance was transferred in 17/34 (50%) of events. Conclusions: Majority of plasmids carrying bla_CTX-M-15 were conjugatively transferred by IncF plasmids along with non-beta lactam resistance. There is a need for more research on plasmids to understand how plasmids especially multi replicon plasmids interact and the effect of such interaction on conjugation. One Health approach is to be intensified to address antimicrobial resistance which is a public health threat.

Clonal Clusters, Molecular Resistance Mechanisms and Virulence Factors of Gram-Negative Bacteria Isolated from Chronic Wounds in Ghana

Wound infections are common medical problems in sub-Saharan Africa but data on the molecular epidemiology are rare. Within this study we assessed the clonal lineages, resistance genes and virulence factors of Gram-negative bacteria isolated from Ghanaian patients with chronic wounds. From a previous study, 49 Pseudomonas aeruginosa, 21 Klebsiellapneumoniae complex members and 12 Escherichia coli were subjected to whole genome sequencing. Sequence analysis indicated high clonal diversity with only nine P. aeruginosa clusters comprising two strains each and one E. coli cluster comprising three strains with high phylogenetic relationship suggesting nosocomial transmission. Acquired beta-lactamase genes were observed in some isolates next to a broad spectrum of additional genetic resistance determinants. Phenotypical expression of extended-spectrum beta-lactamase activity in the Enterobacterales was associated with bla_CTX-M-15 genes, which are frequent in Ghana. Frequently recorded virulence genes comprised genes related to invasion and iron-uptake in E. coli, genes related to adherence, iron-uptake, secretion systems and antiphagocytosis in P. aeruginosa and genes related to adherence, biofilm formation, immune evasion, iron-uptake and secretion systems in K. pneumonia complex. In summary, the study provides a piece in the puzzle of the molecular epidemiology of Gram-negative bacteria in chronic wounds in rural Ghana.

Insects, Rodents, and Pets as Reservoirs, Vectors, and Sentinels of Antimicrobial Resistance

This paper reviews the occurrence of antimicrobial resistance (AMR) in insects, rodents, and pets. Insects (e.g., houseflies, cockroaches), rodents (rats, mice), and pets (dogs, cats) act as reservoirs of AMR for first-line and last-resort antimicrobial agents. AMR proliferates in insects, rodents, and pets, and their skin and gut systems. Subsequently, insects, rodents, and pets act as vectors that disseminate AMR to humans via direct contact, human food contamination, and horizontal gene transfer. Thus, insects, rodents, and pets might act as sentinels or bioindicators of AMR. Human health risks are discussed, including those unique to low-income countries. Current evidence on human health risks is largely inferential and based on qualitative data, but comprehensive statistics based on quantitative microbial risk assessment (QMRA) are still lacking. Hence, tracing human health risks of AMR to insects, rodents, and pets, remains a challenge. To safeguard human health, mitigation measures are proposed, based on the one-health approach. Future research should include human health risk analysis using QMRA, and the application of in-silico techniques, genomics, network analysis, and ’big data’ analytical tools to understand the role of household insects, rodents, and pets in the persistence, circulation, and health risks of AMR.

The Persistence of Escherichia coli Infection in German Cockroaches (Blattodea: Blattellidae) Varies Between Host Developmental Stages and is Influenced by the Gut Microbiota

The German cockroach, Blatella germanica (L.), is a suspected vector of several enteric bacterial pathogens, including Escherichia coli, among livestock and humans. However, little is known about the factors that influence bacterial transmission by cockroaches. Here, we orally infected B. germanica with various laboratory and field strains of E. coli and examined bacterial titers over time to shed new light on the factors that influence the dynamics of infection. Our results reveal that a laboratory strain of E. coli is largely cleared within 48 h while one field isolate can persist in a majority of cockroaches (80-100%) for longer than 3 d with minimal impact on cockroach longevity. We also find that the ability to clear some strains of E. coli is greater in cockroach nymphs than adults. Notably, no differential expression of the antimicrobial gene lysozyme was observed between nymphs and adults or in infected groups. However, clearance of E. coli was significantly reduced in gnotobiotic cockroaches that were reared in the absence of environmental bacteria, suggesting a protective role for the microbiota against exogenous bacterial pathogens. Together, these results demonstrate that the interactions between cockroaches and enteric bacterial pathogens are highly dynamic and influenced by a combination of microbial, host, and environmental parameters. Such factors may affect the disease transmission capacity of cockroaches in nature and should be further considered in both lab and field studies.

Rapid screening and characterization of bacteria associated with hospital cockroaches (Blattella germanica L.) using MALDI-TOF mass spectrometry

AIMS

The study aimed to explore the diversity of culturable microbiota colonizing the alimentary tract and outer surfaces of German cockroaches (Blattella germanica) captured in a health care facility.

METHODS AND RESULTS

Microbial identification was conducted using Matrix Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) Biotyper and 16S rRNA sequencing. A total of 181 bacteria strains were isolated from 25 cockroach specimens and the MALDI-TOF MS-based assay yielded direct identification of 96·5% (175 out of 181) of the strains at the species level. The proteomic fingerprinting mainly revealed strains belonged to Gram-negative Enterobacteria (103) with six different genera that were characterized including Citrobacter, Klebsiella, Kluyevera, Leclercia, Morganella and Serratia. In addition, Pseudomonas sp. strains ranked in second with 29·8% (54 strains) followed by Staphylococcus sp. (6·62%) and Enterococcus sp. (1·65%). A large number of these bacteria (n = 90, 49·72%) was found in cockroaches captured in the maternity ward, whereas 45 strains (24·8%) were recovered in the paediatric ward. Altogether, 24 bacterial species were identified from both the external surface and digestive tract of the insect, of which Serratia marcescens presented the major group (n = 80, 44·19%) followed by Pseudomonas aeruginosa (n = 53, 29·28%) and Klebsiella oxytoca (n = 9, 4·94%).

CONCLUSION

The findings showed a high prevalence of bacterial pathogens harboured in the body and alimentary tract of B. germanica captured in a health care facility.

SIGNIFICANCE AND IMPACT OF THE STUDY

This investigation shows the possible role of German cockroaches as a source for bacterial pathogens, increasing the likelihood of direct transmission of healthcare associated infections, and thereby representing a public health risk. In addition, the present study revealed a high discriminatory power of the mass spectra investigation and a competent bacterial typing tool that extends phenotypic and genotypic approaches, which allows new possibilities for fast and accurate diagnosis in medical entomology.

Broad-Spectrum Cephalosporin-Resistant and/or Fluoroquinolone-Resistant Enterobacterales Associated with Canine and Feline Urogenital Infections

The aim of the present study was to characterize Enterobacterales resistant to 3rd and 4th generation cephalosporins, carbapenems and/or fluoroquinolones, isolated from dogs and cats with urogenital infections. In total, 36 strains (Escherichia coli (n = 28), Klebsiella pneumoniae (n = 3), Serratia marcescens, Raoultella ornithinolytica, Proteus mirabilis, Citrobacter portucalensis and Enterobacter cloacae (each n = 1)) were included in the present study, 28 from Austria and 8 from Serbia. Isolates were characterized by a polyphasic approach including susceptibility pheno- and genotyping and microarray-based assays. Escherichia (E.) coli isolates were additionally characterized by two-locus (fumC and fimH) sequence phylotyping and multi-locus sequence typing (MLST) of selected isolates. MLST of carbapenem-resistant Enterobacter cloacae isolates was also performed. Among E. coli, the most dominant phylogenetic group was B1 (27.8%), followed by C, (16.6%), A and Clade II (5.5% each), B2 and F (2.77% each). The most predominant β-lactam resistance genes were blaTEM (70%) and blaCTX-M (38.8%), blaCMY (25%). blaNDM was detected in one carbapenem-resistant Enterobacter cloacae ST114. The most common ST among selected E. coli was 744 (10.7% isolates). The pandemic clones ST131 and ST648 carrying CTX-M-15 were also detected. Remaining STs belonged to 469, 1287, 1463 and 1642. E. coli clonotyping revealed 20 CH types. Based on the presence of certain virulence genes, three isolates were categorized as ExPEC/UPEC. The most prevalent virulence factors were fimH detected in 61%, iucD and iss both in 55%, iroN in 27.8%, papC in 13.8% and sat in 8.3% isolates.