Susceptibility profiles of bacteria causing urinary tract infections in Southern Tunisia

Review and analysis of the overlapping threats of carbapenem and polymyxin resistant E. coli and Klebsiella in Africa

BACKGROUND

Carbapenem-resistant Enterobacterales are among the most serious antimicrobial resistance (AMR) threats. Emerging resistance to polymyxins raises the specter of untreatable infections. These resistant organisms have spread globally but, as indicated in WHO reports, the surveillance needed to identify and track them is insufficient, particularly in less resourced countries. This study employs comprehensive search strategies with data extraction, meta-analysis and mapping to help address gaps in the understanding of the risks of carbapenem and polymyxin resistance in the nations of Africa.

METHODS

Three comprehensive Boolean searches were constructed and utilized to query scientific and medical databases as well as grey literature sources through the end of 2019. Search results were screened to exclude irrelevant results and remaining studies were examined for relevant information regarding carbapenem and/or polymyxin(s) susceptibility and/or resistance amongst E. coli and Klebsiella isolates from humans. Such data and study characteristics were extracted and coded, and the resulting data was analyzed and geographically mapped.

RESULTS

Our analysis yielded 1341 reports documenting carbapenem resistance in 40 of 54 nations. Resistance among E. coli was estimated as high (> 5%) in 3, moderate (1-5%) in 8 and low (< 1%) in 14 nations with at least 100 representative isolates from 2010 to 2019, while present in 9 others with insufficient isolates to support estimates. Carbapenem resistance was generally higher among Klebsiella: high in 10 nations, moderate in 6, low in 6, and present in 11 with insufficient isolates for estimates. While much less information was available concerning polymyxins, we found 341 reports from 33 of 54 nations, documenting resistance in 23. Resistance among E. coli was high in 2 nations, moderate in 1 and low in 6, while present in 10 with insufficient isolates for estimates. Among Klebsiella, resistance was low in 8 nations and present in 8 with insufficient isolates for estimates. The most widespread associated genotypes were, for carbapenems, blaOXA-48, blaNDM-1 and blaOXA-181 and, for polymyxins, mcr-1, mgrB, and phoPQ/pmrAB. Overlapping carbapenem and polymyxin resistance was documented in 23 nations.

CONCLUSIONS

While numerous data gaps remain, these data show that significant carbapenem resistance is widespread in Africa and polymyxin resistance is also widely distributed, indicating the need to support robust AMR surveillance, antimicrobial stewardship and infection control in a manner that also addresses broader animal and environmental health dimensions.

Detection of Clones B2-ST131-C2 and A-ST617 in Escherichia coli Producing Both CTX-M-15 and CTX-M-27 from Tunisian Community Patients

During a two-month period (2017–2018), 336 urine samples positive for Escherichia coli were collected from Tunisian patients. Of the 336 samples, 266 were collected from community patients and 70 from hospital settings. In all, 15 ESBL producers were identified (8 and 7, respectively) and assigned to 13 pulsotypes, including four ESBL-producing E. coli (ESBL-E) with E1 and E2 profiles (2 isolates each) from community patients. The two strains E1 were identified as B2-ST131 subclade C2 and the two isolates E2, A-ST617. The four strains carrying both CTX-M-15 and CTX-M-27, exhibited the multireplicon IncFII/F1A/F1B with the same formula F31:A4:B1. Two isolates with patterns E3 and E4 (Dice coefficient, 78.7%) isolated from community and hospital settings of two geographic areas were assigned to the emerging ST131 C1-M27 subclade and contained the replicon F1:A-:B20. The remaining ESBL-E divided into different sequence types/associated CTX-M: 2 ST131-C2/CTX-M-15 and ST744/CTX-M-55, ST617/CTM-15, ST2973/CTX-M-55, ST6448/CTX-M-15, ST224/CTX-M-15, ST1431/CTX-M-15, and ST38/CTX-M-27, one isolate each. Our study reports for the first time the presence in the Tunisian community of two clones of E. coli, including the virulent clone ST131-C2 harboring both CTX-M-15 and CTX-M-27, and confirms the spread of the emergent clone ST131-C1-M-27, notably in community urinary tract infections.

Molecular Characterization of Enterobacter cloacae Isolated from Urinary Tract Infections

Background: Urinary tract infections represent a major expensive, common public health problem worldwide due to their high prevalence and the difficulties associated with their management. Objectives: This study aimed to characterize the Enterobacter cloacae strains isolated from urinary tract infections in the medical diagnostic laboratories of Shahrekord, Iran. Methods: Urine samples from patients with urinary tract infections from the Shahrekord medical diagnostic laboratories located in Chaharmahal and Bakhtiari Province, Iran, were collected from June 2019 to February 2020. When the samples were cultured, the different isolates of E. cloacae were identified by biochemical tests. Biofilm production capacity was evaluated. Bacterial susceptibility to antibiotics was determined using the Kirby Bauer method, and antibiotic resistance genes were researched by the multiplex PCR technique. Results: In this study, 65 isolates of E. cloacae were obtained. The highest percentage of resistance was observed for co-trimoxazole (84.62%), ampicillin (76.93%), tetracycline (73.85%), and above half of the E. cloacae strain isolates (53,85%) were strongly involved in biofilm production. Some genes, including qnr A, qnr B, qnr S, tetA, tet B, sul1, bla CTXM, bla SHV, and(2)la, ant(3)la, and aac(3)IIa, were detected in the genome of these isolates. Conclusions: The strains are multi-resistant, and their resistance has already reached the carbapenem class. This requires further investigation, and urgent measures must be adopted.

Multidrug-resistant community-acquired urinary tract infections in a northern region of Morocco: epidemiology and risk factors

INTRODUCTION

Urinary tract infection is very common and is the second most frequent reason for consultation in office-based practice. The incidence varies from one country to another. The diffusion of MDR in the community complicates therapeutic management. The objective of this study was to describe the bacterial epidemiology and to determine the risk factors for the acquisition of MDR in community urinary tract infections in our region.

METHODS

This was a retrospective case-control study conducted in the bacteriology laboratory of the Mohammed V Military Teaching Hospital over an 8-month period from 01 October 2015 to 31 May 2016. Cases were defined as patients with community-acquired urinary tract infection with MDR and controls were defined as patients with a urinary tract infection without MDR.

RESULTS

Out of 373 isolates, enterobacteria represented 80%. E. coli represented 59.2%, followed by K. pneumoniae at 15%. The rate of MDR represented 13.4% of which ESBL enterobacteria represented 12.1%. Univariate analysis showed a statistically significant association between male sex (p=0.001), age >65 years (p=0.007), urban origin (p=0.003), previous hospitalization within 3 months (p=0.001) and antibiotic therapy within 6 months (p=0.001) with MDR community-acquired urinary tract infection. On the other hand, multivariate analysis by logistic regression showed that age >65 years (OR=8.4, CI: 2.1-42), previous hospitalization within 3 months (OR=13.4, CI: 3.3-140.2) and antibiotic therapy within 6 months (OR=9.2, CI: 4.1-60.1) were significantly associated to MDR community-acquired urinary tract infection.

CONCLUSIONS

The increase in resistance to enterobacteria in the community prompts a review of the list of antibiotics prescribed for probabilistic management of these infections in our region.

Detection of AmpC and ESBL-producing Enterobacterales isolated from urinary tract infections in Tunisia

Urinary tract infections (UTIs) are the most frequent human infections in community and hospitals. This study aimed to determine the distribution of bacterial uropathogens among urinary tract infections diagnosed within the regional hospital Houcine Bouzaiene (Gafsa, South West Tunisia) during a survey of 54 days from the 8th of November to the 31st of December 2017. Enterobacterales strains were tested for antimicrobial resistance by disk diffusion method and extended-spectrum β-lactamase (ESBL) production was tested by double-disc synergy test. Strains were further subjected to a molecular assessment of ESBL and AmpC β-lactamase production by PCR. Overall, 173 bacterial isolates were studied, out of which 91.3% were Enterobacterales. Escherichia coli was the dominant pathogen, followed by Klebsiella pneumoniae. High to moderate resistance rates were observed, ranging from 66% to 90.7% for penicillins, from 6.7% to 18.6% for cephalosporins and from 16.2% to 25.4% for fluoroquinolones. Enterobacterales with decreased susceptibility to third-generation cephalosporins (3rd GC) carried several resistance genes: blaCTX-M group 1 and group 9, and ACC and FOX AmpC β-lactamase genes. Overall, ESBLs and AmpC β-lactamases were detected in 57% and 14% of the 3rd GC-resistant isolates, respectively. This study proved the high potential of K. pneumaniae species to develop resistance against commonly used antibiotics. Thus, rigorous monitoring of the antibiotic resistance of clinical pathogens have to be implemented in Tunisia. Our results are very relevant to evaluate efficiency of the Tunisian therapeutic strategies against UTIs and adapt them to the emerging problem of antimicrobial resistance.

Global Prevalence and Molecular Epidemiology of mcr-Mediated Colistin Resistance in Escherichia coli Clinical Isolates: A Systematic Review

BACKGROUND AND AIM

The continuing rise in infections caused by multi-drug resistant (MDR) bacteria is one of the most serious public health issues in today's societies. Colistin is a last-resort antimicrobial medication used to treat infections caused by MDR gram-negative bacteria; therefore resistance to this antibiotic is extremely hazardous. The current study aimed to evaluate the global prevalence and distribution of colistin resistance genes among human clinical isolates of Escherichia coli (E. coli) as a systematic review.

METHODS

PubMed, Embase, and Web of Science databases were systematically searched. For further evaluation, all original English-language articles that demonstrated colistin resistance in E. coli clinical isolates published between 2000 and 2020 were examined.

RESULTS

Out of 4857 initial articles, after various stages of review and evaluation, 190 related articles were selected. More than 79 % of the publications selected in this research were published from 2014 to 2020. In Asia, Europe, America, Africa, and Oceania, the prevalence of mobilized colistin resistance (mcr) producing colistin-resistant E. coli was 66.72%, 25.48%, 5.19%, 2.27%, and 0.32 %, respectively.

CONCLUSION

The recent widespread spreading of E. coli strains harboring mcr conferring colistin resistance, especially in Asia and Europe, is concerning and needs more attention.

Soul of the Jukskei River: The Extent of Bacterial Contamination in the Jukskei River in Gauteng Province, South Africa

River water quality is an important health issue as the water is utilised for drinking, domestic and agricultural use in developing countries. This study aimed to investigate the effect water from a major city has on the water quality of the Jukskei River that daylights in Johannesburg, South Africa. The river water samples were analysed for physio-chemical properties, microbiology, antibiotic resistance of bacterial isolates, genetic markers, and potentially toxic metals. Data analysis revealed increased electrical conductivity, total dissolved solids, and turbidity since 2010. Total Coliform and Escherichia coli detected were above the South African water quality guidelines for domestic, recreational, and irrigation purposes. Additionally, sodium, zinc, nickel, lithium, and lead exceeded the guidelines in domestic, recreational, and irrigation water. Pathogenic strains of E. coli (aEPEC, EHEC, EIEC, and EAEC) were isolated from the water. Various other potentially pathogenic organisms that have been implicated as causes of gastro-intestinal, and a wide range of other diseases, were also detected and demonstrated multiple levels of resistance to antibiotics tested. The results show that the river water is a potential health threat to downstream users. These results will feed into the environmental management action plan for Water for the Future (NGO group).

Antimicrobial Susceptibility Patterns of Escherichia coli among Tunisian Outpatients with Community-Acquired Urinary Tract Infection (2012-2018)

Introduction

Community-acquired urinary tract infection is one of the most common reasons for consultation in everyday practice; it represents a major source of antibiotic consumption. Escherichia coli (E. coli) is the main pathogen incriminated.

Objective

The aim of this study was to evaluate antimicrobial susceptibility patterns of community-acquired uropathogenic E coli throughout a 7-year period.

Methodology

All strains of E. coli isolated from urine samples between January 1st 2012 and December 31st 2018 were included. Presence of ≥ 10³ CFU/ml in urine culture media was considered as significant for urinary tract infection. The identification of E. coli strains was realized using standard laboratory techniques. Antibiotic susceptibility testing was performed using the disk diffusion method according to the CA-SFM/ EUCAST criteria.

Results

A total of 1,335 E. coli strains were isolated. Overall susceptibility rates to antimicrobial agents were as follows: ampicillin 39.1%, amoxicillin-clavulanic acid 64.9%, cefotaxime 94.9%, trimethoprim/sulfamethox-azole 67.6%, ciprofloxacin 89.2%, ofloxacin 86.9%, amikacin 98.6%, gentamicin 93.9%, nitrofurantoin 97.6% and fosfomycin 99.3%. All isolates were susceptible to carbapenems. The frequency of extended spectrum beta-lactamases-producing E. coli strains was 4.7%. Susceptibility rates of E. coli for ampicillin, trimethoprim/sulfamethoxazole and amikacin remained relatively stable over the study period, whereas susceptibility to amoxicillin-clavulanic acid, cefotaxime and fluoroquinolones showed a 2-phase pattern. As for gentamicin, a continuous decrease in susceptibility rates was observed.

Conclusion

Antimicrobial susceptibility profiles of uropathogenic E. coli are constantly changing, due to modifications in the antibiogram interpretation criteria and antibiotic prescription habits. Rigorous surveillance of resistance rate is necessary to determine appropriate empirical treatment and limit the spread of multiresistant strains.

Antibiotic Resistance Profile of Uropathogenic Bacteria in Diabetic Patients at the Bafoussam Regional Hospital, West Cameroon Region

Background

Urinary tract infections constitute a major public health concern. The aim of the study is to look into the antibiotic sensitivity profile of uropathogenic bacteria among diabetic individuals in the Diabetology Unit of the Bafoussam Regional Hospital, West Cameroon.

Methods

A cross-sectional study was carried out in Bafoussam Regional Hospital. Urine was collected in a sterile jar previously labelled. The microorganisms were isolated on agar medium and their final identification was carried out on the API20E gallery. The antibiogram was performed using agar diffusion methods.

Results

Escherichia coli (25.30%) and Staphylococcus aureus (19.27%) were the most noticed species in the diabetic patients, whereas Escherichia coli (32.00%) and Klebsiella pneumoniae (22.00%) were the most noticed in non-diabetic patients. There was a significant association between antibiotic resistance and diabetic status (for ceftriaxone: X² = 23.78 and P-value < 0.001; for cefixime: X² = 19.31 and P-value < 0.001; for ceftazidime: X² = 9.45 and P-value = 0.008; for cefotaxime: X² = 10.97 and P-value = 0.004; for cefepime: X² = 27.93 and P-value < 0.001; and for ciprofloxacin: X² = 11.13 and P-value = 0.003). Multidrug resistance rate against some bacterial species were higher in diabetic patients (62.50% for Escherichia coli, 63.16% for Klebsiella pneumoniae, and 78.57% for Staphylococcus aureus) compared with non-diabetic patients (37.50% for Escherichia coli, 36.84% for Klebsiella pneumoniae, and 21.43% for Staphylococcus aureus).

Conclusions

 This study revealed that there is an association between antibiotic resistance and diabetic status. Research and interventions must be focused on the elderly diabetic population in order to fight against the occurrence of drug-resistant uropathogenes.

Molecular drivers of emerging multidrug resistance in Proteus mirabilis clinical isolates from Algeria

OBJECTIVES

The aim of this study was to characterise the molecular drivers of multidrug resistance in Proteus mirabilis isolated from Algerian community and hospital patients.

METHODS

A total of 166 P. mirabilis isolates were collected from two hospitals and eight private laboratories from four cities (Khemis Miliana, Aïn Defla, Oran and Chlef) located in northwestern Algeria. All isolates were identified by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Antimicrobial susceptibility testing was performed by the disk diffusion and Etest methods. Genes encoding AmpC β-lactamases, extended-spectrum β-lactamases (ESBLs), quinolone resistance and aminoglycoside-modifying enzymes (AMEs) as well as plasmid replicon typing were characterised by PCR. Clonal relationships were also determined by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) typing and were compared with MALDI-TOF/MS proteomic typing.

RESULTS

Of the 166 P. mirabilis isolates, 14 (8.4%) exhibited resistance to important antibiotics, including amoxicillin, amoxicillin/clavulanic acid, cefotaxime, gentamicin and ciprofloxacin, of which 4/14 (28.6%) had an ESBL genotype (bla_CTX-M-2) and 10 (71.4%) had an AmpC/ESBL genotype (bla_CMY-2/bla_TEM-1). AME genes were detected in all isolates, including ant(2'')-I, aac(3)-I, aac(6')-Ib-cr and aac(3)-IV. The qnrA gene was identified in 13 isolates (7.8%). ERIC-PCR showed one predominant clone, with eight bla_CMY-2-producing isolates from UHC Oran belonging to profile A clustering together in the MALDI-TOF/MS dendrogram.

CONCLUSION

Here we report the first description of AME and plasmid-mediated quinolone resistance genes among ESBL- and/or AmpC β-lactamase-producing P. mirabilis isolates from community- and hospital-acquired infections in northwestern Algeria.

Antimicrobial susceptibility profiles of bacteria causing urinary tract infections in Mexico: Single-centre experience with 10 years of results

OBJECTIVES

The aim of this retrospective study was to describe urinary tract infections (UTIs) diagnosed in a single centre in Mexico through 10 years of results, with a particular emphasis on the aetiology, patterns of antimicrobial susceptibility and incidence of extended-spectrum β-lactamase (ESBL)-producing strains.

METHODS

This study involved all urine samples analysed during the period March 2007 to September 2017 in a single centre in Mexico. Isolated uropathogens were identified to species level using routine laboratory methods, and antimicrobial susceptibility was determined by the disk diffusion method.

RESULTS

Overall, 859 urinary isolates were identified, including 582 (67.8%) Escherichia coli, 69 (8.0%) Enterococcus faecalis, 29 (3.4%) Klebsiella pneumoniae, 24 (2.8%) Proteus mirabilis, 24 (2.8%) Pseudomonas aeruginosa, 23 (2.7%) Candida albicans, 18 (2.1%) Streptococcus agalactiae and 10 (1.2%) Candida glabrata. Patient sex and age were the main risk factors associated with UTI in this population. Nitrofurantoin together with fosfomycin and amikacin had the highest percentages of susceptibility. Of the 859 isolates, 213 (24.8%) presented a positive double-disk synergy test indicating the presence of an ESBL phenotype, with E. coli showing a gradual increase in ESBL-producing isolates over time.

CONCLUSIONS

These results provide additional evidence in relation to the role of different bacterial species as aetiological agents of UTI as well as antimicrobial susceptibility information that will help to guide the selection of antimicrobial treatment for UTIs and the prevalence of ESBL-producing strains over a 10-year period in a Mexican centre.