Characterisation of Extended-Spectrum β-Lactamases among Multidrug Resistant Enterobacteriaceae from Sudan

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.

Occurrence of Antibiotic Resistant Bacteria in Flours and Different Plant Powders Used in Cuisine

In recent years, several alimentary diseases have been connected with the consumption or tasting of raw flour and dough. Microbiological quality concern is also raising due to increased consumer demand for plant powders, while some of them can be consumed without prior thermal processing. In this study, we have focused on the occurrence of antibiotic-resistant coliform bacteria and enterococci in flour, plant powder and dough from Slovak retail. Our results indicated the presence of both total and antibiotic-resistant coliform bacteria and enterococci in the flour and powder samples. Lower numbers of the total, as well as resistant bacteria, were detected in flours compared to plant powders. Coliform bacteria isolates were predominantly identified as Klebsiella spp. and Enterobacter spp. Ampicillin resistance appeared in 97% of isolates followed by chloramphenicol resistance (22%) and tetracycline resistance (17%). The presence of the bla_SHV gene was confirmed in 13% of isolates. The tetA and tetE genes were present in 25% of isolates of coliform bacteria. The presence of enterococci was detected only in plant powders. Antibiotic-resistant strains were identified as the following: Enterococcus casseliflavus, E. gallinarium and E. faecium. Despite the isolates showing resistance to vancomycin, the presence of the vanA gene was not detected. The majority of antibiotic-resistant isolates belonged to the group of medium biofilm producers. None of these isolates showed efflux pump overproduction. Antibiotic-resistant coliform bacteria and enterococci were not detected in the processed doughs.

Antimicrobial susceptibility testing profiles of ESBL-producing Enterobacterales isolated from hospital and community adult patients in Blantyre, Malawi

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Extended-spectrum β-lactamase (ESBL) strains are an increasingly global health issue

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ESBL-Enterobacteriaceae isolates affected 64% of inpatients and 36% of outpatients

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ESBL-E isolates had high antimicrobial resistance; most were multi-drug resistant

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Surveillance systems are needed to monitor antimicrobial resistance in Malawi

Objective

There is a paucity of data on antimicrobial resistance (AMR) in Malawi. Here we present a study of AMR of extended-spectrum β-lactamases-producing Enterobacterales (ESBL-E) isolated from hospital and community settings in Blantyre, Malawi.

Design and Methods

A cross-sectional study was conducted between March and November 2020, involving 403 adult participants aged ≥18 years. Screening for ESBL-E was performed using CHROMagar ESBL medium. Production of ESBLs was confirmed by a combination disk test method. Antimicrobial susceptibility was tested using the agar disk diffusion method in accordance with the Clinical Laboratory Standards Institute's 2019 guidelines.

Results

The mean resistance rate of ESBL-E to antimicrobial agents tested was 49.2% (range from 1.4%–92%). The highest resistance rates were observed for trimethoprim-sulfamethoxazole (92%), amoxicillin and ceftriaxone (79%), doxycycline (75%) and gentamicin (72%). Carbapenems (meropenem and imipenem) were highly active against isolates. The overall rate of multi-drug resistant (MDR) ESBL-E was 47%. The highest MDR was found in Yersinia enterocolitica (51%) and the least in Serratia spp. (40%).

Conclusions

We found a high resistance rate of ESBL-E isolates to antimicrobial agents; the majority were MDR. Surveillance systems are recommended to monitor AMR in Malawi.

Molecular detection of beta-lactamase blaCTX-M group 1 in Escherichia coli isolated from drinking water in Khartoum State

This study aimed to detect the bla_CTX-M group 1 in Escherichia coli (E. coli) isolated from drinking water in Khartoum State. Two hundred and eighty water samples were collected randomly from different areas, places, and sources from the state and examined for the presence of E. coli as a fecal contamination indicator. Isolation and identification of E. coli were performed using culture characteristics on different culture media and biochemical reactions. An antimicrobial sensitivity test was performed for all isolated E. coli using agar disk diffusion method. DNA was extracted by boiling method, and bacterial genomic DNA used as a template to detect bla_CTX-M group 1 by PCR. Results showed 86 (30.7%) E. coli were isolated out of 280 water samples. Antimicrobial susceptibility testing revealed the highest resistant percentage was 59% for tetracycline, followed by 35% for gentamycin, while for chloramphenicol and cefotaxime was 22 and 20%, respectively. bla_CTX-M group 1 was detected in about 40% of all isolates. This study concludes that drinking water in Khartoum State may be contaminated with feces and might be a possible source for transferring resistant bacteria. Thus, it may be one of the critical causes of increasing reports of antimicrobial resistance in Khartoum State.

Antibiotics Profile, Prevalence of Extended-Spectrum Beta-Lactamase (ESBL), and Multidrug-Resistant Enterobacteriaceae from Different Clinical Samples in Khartoum State, Sudan

One of the global requirements for controlling the occurrence of resistance to antimicrobial drugs is to understanding the resistivity profile of various clinical isolates. Therefore, this study aimed to deliver the indication of different resistant profiles of clinically isolated Enterobacteriaceae from different sources of samples from Khartoum state, Sudan, and to determine the prevalence rate of extended-spectrum beta-lactamase (ESBL), multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) bacteria. A total of 144 Gram-negative bacteria were collected from different sources (vaginal swab, urine, catheter tip, sputum, blood, tracheal aspirate, pus, stool, pleural fluid, and throat swab). Samples were subcultured and identified according to their cultural characteristics and biochemical tests. Antimicrobial susceptibility test was performed for twenty-four antibiotics from eleven categories against all isolated Enterobacteriaceae according to the recommendation of Clinical and Laboratory Standards Institute (CLSI). The result showed that out of 144 isolates, Escherichia coli and Klebsiella pneumoniae were predominant isolates with the percentage of 47.9 and 25%, respectively. The prevalence of ESBL was higher in K. pneumonia (38.9%) than E. coli (34.8%). All isolated E. coli were sensitive to nitrofurantoin and tigecycline. There was a high prevalence of MDR Enterobacteriaceae, and only one isolate was XDR, while PDR was zero for all isolated bacteria. Active antimicrobial-resistant (AMR) observation through constant data sharing and management of all stakeholders is crucial to recognize and control the AMR global burden. Also, effective antibiotic stewardship procedures would be applied to limit the unreasonable expenditure of antibiotics in Sudan.