Metallo-beta-lactamase Producers Research Articles

Detection of Carbapenemase-Producing Enterobacterales: A Comparative Analysis of Available Phenotypic Methods

Background: Carbapenems serve as a critical last-line defence against infections from multidrug-resistant Enterobacterales. The increasing prevalence of CRE (carbapenem-resistant Enterobacterales) poses significant challenges in clinical settings. This greatly complicates the handling of gram-negative bacilli (GNB) infections and represents a significant global health threat. Aim: This study evaluates and contrasts different phenotypic techniques used to identify carbapenemase-producing Enterobacterales isolated from various clinical samples. Objectives: To compare the accuracy and reliability of Combined Disc Test (CDT) and Modified Carbapenem Inactivation Method/EDTA - Carbapenem Inactivation Method (mCIM/eCIM) in identifying Metallo-beta-lactamase (MBL)-producing Enterobacterales. Methods: All clinical specimens submitted for culture and sensitivity testing at the Department of Microbiology were analysed to isolate and identify Enterobacterales. Carbapenemase production was assessed through using the phenotypic CDT Confirmation was carried out using the mCIM and eCIM in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: During a two-year period, 254 strains of Enterobacterales were isolated. Among those, 80/254 (31.49%) isolates exhibited resistance to the Imipenem (IMP) disc. The CDT identified 30/80 (37.5%) isolates as serine carbapenemase producers and 50/80 (62.5%) isolates as MBL producers. In comparison, the mCIM/eCIM methods detected 26/80 (32.5%) isolates as serine carbapenemase producers, 48/80 (60.0%) isolates as MBL producers, and 6/80 (7.5%) isolates were tested negative for carbapenemase production. Conclusion: This study evaluates the precision and effectiveness of the mCIM/eCIM and CDT methods for identifying CRE. The combination of the mCIM and eCIM tests may be a more reliable phenotypic method for detecting carbapenemase compared to the CDT.

Occurrence and Antibiotic Resistance Profiles of Metallo Beta Lactamase Producing Pseudomonas aeruginosa among Clinical Isolates in Enugu Metropolis, Nigeria

Introduction: Antibiotic resistance is rising worldwide, posing a challenge for contemporary medicine. Metallo-beta-lactamases (MBLs) confer resistance to beta-lactam antibiotics other than monbactams. It threatens public health because of its vast scope of action and quick spread. The study was undertaken to assess the occurrence of MBL in clinical isolates of Pseudomonas aeruginosa in the Enugu metropolis and to determine their resistance profile. Materials and Methods: The work was conducted from October 2020 to July 2021 in the microbiology laboratory of the University of Nigeria Teaching Hospital, Ituku-Ozalla. A total of 127 non-duplicate bacterial isolates recovered from clinical samples including wounds, urine, sputum, ear discharge, and catheter tip processed in the microbiology laboratory of four referral hospitals within the Enugu metropolis was used for the study. Isolates were identified and characterized using standard microbiology protocols. Antimicrobial susceptibility was done using the Kirby-Bauer disc diffusion method. Phenotypic detection of Metallo-beta-lactamase production was done using the Combined Disk diffusion Test (CDDT). Results: Of the 127 isolates, 68 (53.5%) were resistant to imipenem. Among these, 35 strains were positive for MBL production while 33 isolates were non-MBL producers. The highest percentage occurrence of MBL producers was recorded from catheter tips 33% followed by urine 30.6%. Both MBL producers and non-MBL producers displayed high resistance to most of the antibiotics used except Aztreonam. Conclusion: The overall occurrence of MBL among Pseudomonas aeruginosa in our study was found to be 27.6%. MBL-producing strains showed higher resistance than the non-MBL-producing strains. Aztreonam was the most potent antibiotic. The most effective approaches to combating this organism include early detection, stringent antibiotic regimens, and adherence to infection control measures.

Prevalence of metallo-beta-lactamase in clinical isolates of Pseudomonas aeruginosa and Proteus mirabilis in Benin City, Nigeria

Carbapenems are the prime choice of treatment for severe cases of infections caused by Multi-Drug-Resistant Pseudomonas aeruginosa and Proteus mirabilis. Nevertheless, Metallo-Beta-Lactamase (MBL) production by these organisms has led to carbapenem resistance which is a global threat. This study aimed to determine the prevalence and antimicrobial susceptibility profile of MBL in clinical isolates of Pseudomonas aeruginosa and Proteus mirabilis in Benin City, Nigeria. 354 non monotonous clinical isolates of Pseudomonas aeruginosa (282) and Proteus mirabilis (72) used were obtained from various clinical samples from tertiary hospitals in Benin City. Identification of these isolates were done using standard microbiological techniques. Antimicrobial susceptibility test was performed using Kirby-Bauer disk diffusion method. MBL production was detected using Imipenem Ethylene-Diamine-Tetra-Acetic Acid combined disc test method. Of the total 354 clinical isolates tested, 115 (32.48%) were MBL and the prevalence of this resistant isolates was significantly higher in Pseudomonas aeruginosa (46.8%) compared to Proteus mirabilis (P=0.0001). Among the metallo-beta-lactamase producing isolates of Pseudomonas aeruginosa higher prevalence were reported from Pleural fluid and cerebrospinal fluid samples with 6 (100%) and 3 (100%) respectively. This difference was statistically significant (P=0.0001). Susceptibility testing showed that isolates that produced beta-lactamase demonstrated poorly against cephalosporin, amoxicillin-clavulanate, gentamicin and floroquinones than non-beta- lactamase producers. A prevalence of 46.8% was reported for MBL producing Pseudomonas aeruginosa and 12.5% was reported for MBL producing Proteus mirabilis. Isolates that produced the MBL enzyme were more resistant to antibacterial agents. Measures to control and curb the spread of MBL producing clinical isolates are highly advocated

Molecular Analysis of Antibiotic Resistance in CarbapenemResistant Pseudomonas aeruginosa Isolates Isolated from Clinical Samples

Pseudomonas aeruginosa is an opportunistic pathogen that causes increased morbidity and mortality in risky patient groups. Nowadays, carbapenem resistance has become a threat and resistance genes are spreading among species through mobile genetic elements. The dissemination of carbapenemases among P.aeruginosa is a serious public health concern due to its limited options for the treatment of bacterial infections. In this study, it was aimed to investigate the molecular epidemiology of 47 carbapenem resistant P.aeruginosa (CRPA) isolates derived from various clinical samples from the Central Laboratory Bacteriology Unit of Kocaeli University Research and Training Hospital between October 2021 and March 2023. The rates of resistance to the antibiotics, some carbapenemase and virulence genes, conjugative resistance plasmids, integron gene cassette contents and the clonal similarity of the isolates were investigated and then epidemiologically evaluated. In the study, identification of the bacterial isolates and their susceptibility to some antibiotics (imipenem, meropenem, aztreonam, amikacin, netilmicin, tobramycin, piperacillin, piperacillin/tazobactam, ceftazidime, cefepime, ciprofloxacin and levofloxacin) were determined by the VITEK® 2 Compact automated system. Metallo-beta-lactamase (MBL) production of the isolates was demonstrated by the imipenem/meropenem-EDTA (IMP/MEM-EDTA) combined disc method. Conjugation experiments were performed by the broth mating method. Alkali lysis method was used in plasmid DNA isolations. Co-transferred antibiotic resistances in transconjugants were detected by disc diffusion method. Carbapenemase genes (blaIMP , blaVIM , blaNDM , blaKPC and blaOXA-48 ), integron gene cassettes (class 1 and class 2) and virulence genes (lasR and rhlR) were screened by specific polymerase chain reactions (PCRs). Clonal relationships of the CRPA isolates were investigated by evaluating the DNA f ingerprintings obtained from the ERIC (enterobacterial repetitive intergenic consensus)-PCR assay. The highest resistance rate of the isolates were to levofloxacin, while the lowest resistance rates were observed against tobramycin, gentamicin and amikacin. MBL production was detected in 25 (53.2%) isolates. In conjugation experiments, 12 (25.5%) isolates were detected to harbour conjugative resistance plasmids. In 90% of the CRPA isolates, lasR and rhlR biofilm genes (encoding for the transcriptional activator protein) were detected by PCR. The blaVIM gene was detected in six (12.8%) isolates. The blaNDM gene was detected in five (10.6%) isolates and the blaOXA-48 gene was detected in three (6.4%) isolates. The blaKPC and blaIMP genes were not detected in CRPA isolates. It was determined that two (16.6%) of the isolates that carried the blaVIM gene, one (8.3%) carried the blaNDM gene and one (8.3%) carried the blaOXA-48 gene contained conjugative plasmids.In integron-specific PCRs, intI1 gene was positive in 39 (82.9%) isolates, while class 1 integron gene cassettes were detected in 24 isolates (51%). IntI1 positive six isolates were found to harbour class 1 integron gene cassettes-bearing conjugative plasmids. Class 2 integrons were not found in the CRPA isolates. Dendrogram analysis of ERIC-PCR patterns showed that there was no clonal similarity between the CRPA isolates and the isolates did not spread by cross-contamination. As a result, it has been observed that most of the CRPA isolates which have the potential to form biofilms, are highly resistant to other antibiotic groups other than carbapenems and can co-transfer some resistances (ceftazidime, cefepime, ciprofloxacin, levofloxacin, piperacillin-tazobactam) with conjugative resistance plasmids. It is thought that it would be useful to follow molecular epidemiology in the resistance gene reservoirs of these strains which have the potential to cause epidemics in the clinical arena.

Bacteriological evaluation, antibiogram, and phenotypic detection of MBL-producing gram-negative bacteria isolated from outdoor patients with Otorrhea attending Ayub Medical Complex

Otitis media is frequently prevalent in developing countries and is primarily caused by bacteria. The current study aimed to study the patients to assess the occurrence rate, susceptibility pattern, and prevalence rate of metallo beta-lactamase (MBL) producing gram-negative bacteria to prevent the prevalent strains and direct the physicians to appropriate antibiotic therapy. The research study was conducted over nine-months, from November 2020 to July 2021, in which a total of 110 samples were collected from the outdoor-patients’ ear, nose, and throat (ENT) wards using sterile swabs and inoculated immediately on suitable culture media. The isolates were identified via conventional biochemical tests, and the susceptibility pattern of each isolate was tested using the Kirby-Bauer disc diffusion method. Out of the 110 total samples, merely 88.18% (97/110) ear samples were detected positive for the various strains of bacteria both in male and female patients with a mean age of 18.21 ± 15.86, contributing 54.64% and 45.36%, respectively. The most prevalent bacterial strain was Staphylococcus aureus (49.48%), followed by Pseudomonas aeruginosa (16.50%), Proteus spp. (13.40%), S. epidermidis (7.22%), E. coli (6.19%), S. saprophyticus (4.12%), and Klebsiella spp. (3.09%). Of the gram-negative isolated strains, only 18.75% (3/16) of the P. aeruginosa strains exhibited MBL production. A high prevalence rate was observed in the age-group 0–4 years (19.58%), followed by the age-groups, 5–9 and 15–19 (16.49% each), and the age-group >39 (10.31%). Levofloxacin, ciprofloxacin, amikacin, and fusidic acid were highly effective against the gram-positive, whereas ciprofloxacin, amikacin, and levofloxacin were potent against the gram-negative (except P. aeruginosa), while carbenicillin, meropenem and imipenem against the P. aeruginosa. The MBL-producers were highly (100%) resistant to IMP and MEM while highly (100%) sensitive to CAZ. In conclusion, the current study showed a high prevalence of S. aureus, P. aeruginosa, and MBL-producing P. aeruginosa (18.75%). Nevertheless, a high degree of resistance to antibiotics was noted, which could not be ignored.

Food chain milieus: Potential reservoirs and sources of metallo-beta-lactamase-producing antibiotic-resistant bacteria in Southeast Nigeria

Concerted efforts are needed to mitigate the development and transmission of bacterial resistance in the general environment. Metallo-beta-lactamase (MBL) is a carbapenemase that allows bacteria to resist the antimicrobial onslaught of carbapenems (e.g., imipenem [IPM]). We investigated the prevalence of MBL-producing Pseudomonas aeruginosa in poultry farms. Samples from poultry birds (n = 65) were studied for the isolation of antibiotic-resistant bacteria according to the Clinical and Laboratory Standards Institute criteria. The modified Hodge test was used to phenotypically detect MBL. Polymerase chain reaction (PCR) was used to confirm MBL production in the test isolates. To confirm the presence of plasmids in the isolates, a plasmid curing experiment was conducted. High levels of reduced susceptibility to cefotaxime (77.8%), IPM (69.4%), gentamicin (63.9%), amikacin (58.3%), fosfomycin (55.5%), ciprofloxacin (66.7%), tetracycline (75%), ertapenem (55.5%), sulfamethoxazole-trimethoprim (66.7%), and cefoxitin (52.8%) were recorded in the P. aeruginosa isolates. A total of 23 isolates of P. aeruginosa produced MBL. The presence of MBL genes in these P. aeruginosa isolates (n = 23) was confirmed by PCR, which detected blaIMP-1 (47.8%) and blaIMP-2 (26.1%). The isolates were multidrug resistant (50%) and carried plasmids, indicating horizontal transmission of resistance genes. Genes for bacterial resistance can be transmitted through mobile genetic elements. Therefore, sustainable interventions are needed to mitigate antibiotic use in poultry practices in Nigeria to curb the development of MBL-producing bacteria arising from selective (antibiotic) pressures in such an environment. These interventions can help to detect and stop infections caused by resistant bacteria before they become clinical cases in our hospitals.

Metallo-Beta-Lactamase Producing Isolates of Escherichia coli and Klebsiella pneumoniae and their Resistance Profiles in Enugu, Nigeria: A Threat to Public Health

Background: A potential threat to public health is the rapidly spreading enterobacteriaceae, especially Escherichia coli and Klebsiella pneumoniae which produce metallo-beta-lactamases (MBL). This study evaluated the prevalence of metallo-beta-lactamase (MBL) from clinical and non-clinical sources in Enugu Metropolis.
 Methodology: The study was conducted in the Microbiology Laboratory of the University of Nigeria Teaching Hospital, Ituku-Ozalla between October 2020 and July 2021. A total of 150 isolates including 85 and 65 isolates of Escherichia coli and Klebsiella pneumoniae respectively was recovered. Standard microbiology procedures were used to identify and characterize the isolates. Antimicrobial susceptibility was done using the Kirby-Bauer disc diffusion technique. Phenotypic detection of Metallo-beta-lactamase production was determined using Combined Disk Tests.
 Results: Imipenem resistance was detected in 22 (25.9%) isolates of E. coli and 18 (27.7%) isolates of K. pneumoniae. Of the 22 strains of E. coli that were imipenem resistant, 8 (9.4%) and 14 (16.5%) were found to be MBL producers and non-MBL respectively. Of the 18 strains of Klebsiella pneumoniae that were imipenem resistant, 10 (15.4%) were MBL producers and 8 (12.3%) were non-MBL producers. The highest prevalence of MBL was recovered from urine sources in both E. coli and K. pneumonieae. All MBL-producing isolates were multidrug resistant.
 Conclusion: The overall prevalence of MBL in this study was 12.0%. Public health is at risk due to the occurrence of metallo-beta-lactamase. Antimicrobial stewardship and the implementation of infection control strategies are required to halt the spread of these resistant bacteria in the environment. The use of antibiotics should be with utmost prudence.

Molecular study of blaVIM and blaIMP genes in Acinetobacter baumannii strains isolated from burn patients in Duhok City, Iraq.

Acinetobacter baumannii (A. baumannii) is an opportunistic pathogenic bacterium mainly associated with hospital acquired infections and in immunocompromised individuals who stay in hospitals for a long time. In recent years, it has become increasingly resistant to many different types of antibiotics. The production of the metallo-beta-lactamase (MBL) enzyme is one of the primary causes of this resistance. This study aimed to detect the presence of MBL genes that belong to the verona integrin metallo-β-lactamase (bla-VIM) and imipenemase (bla-IMP) groups in the isolates of Acinetobacter baumannii from burn patients. One hundred and seventeen (117) isolates of A. baumannii were obtained from patient specimens using traditional methods followed by using the VITEK 2 (BioMérieux, Les Pennes-Mirabeau, France) identification system. Metallo β-lactamases were detected in the imipenem-resistant strains by using imipenem disks on Muller-Hinton agar. The polymerase chain reaction (PCR) technique was utilized to examine 117 isolates for the detection of MBLs encoding genes such as bla-VIM, and bla-IMP. Imipenem resistance was detected in 78.6% of the patients. The PCR assays of the isolates identified bla-VIM-1, bla-VIM-2, bla-IMP-1 and bla-IMP-2 genes at the rates of 17%, 40.1%, 29.9% and 4.2%, respectively. The findings suggest that the majority of A. baumannii isolates harbour one or more of the detected genes, signifying that the production of MBLs plays a pivotal role in resistance mechanisms.

Prevalence of drug resistant Enterobacteriaceae in a Nepalese tertiary care hospital.

Antimicrobial resistance in Enterobacteriaceae is an emerging global public health problem. Numerous studies have reported community-acquired AmpC beta-lactamase and extended spectrum beta-lactamase (ESBL) producing Enterobacteriaceae in Nepal. However, there are limited data on community-acquired Metallo-beta-lactamase (MBL) producing Enterobacteriaceae. A hospital-based descriptive cross-sectional study was conducted using 294 Enterobacteriaceae isolates from a total of 2,345 different clinical specimens collected from patients attending a tertiary care hospital in Nepal. Bacteria were isolated using standard microbiological growth media and identified using biochemical tests. For antimicrobial susceptibility testing, Kirby-Bauer disc diffusion technique was used. AmpC, ESBL, and MBL productions were detected by using combined disc method. AmpC, ESBL, and MBL productions were detected in 19.4%, 29.6%, and 8.5% of total Enterobacteriaceae isolates respectively. Higher rates of beta-lactamases production were seen among the isolates from in-patients in comparison with those from out-patients. However, 11.6%, 25%, and 3.7% of the total isolates from out-patients were AmpC, ESBL, and MBL producers respectively. The co-production of the beta-lactamases was also detected, with two Klebsiella pneumoniae isolates producing all three beta-lactamases. One MBL producing Proteus vulgaris isolate that was pan-resistant with no remaining treatment options was also isolated. Prevalence of drug resistant Enterobacteriaceae in our study was very high. Detection of AmpC, ESBL, and MBL positive isolates from out-patients, who did not have recent history of hospital visit, indicated the community dissemination of the drug resistant bacteria. This is a matter of great concern and an immediate attention to formulate strategies to prevent further development and spread of antibiotic resistance is required.

Phenotypic detection of extended spectrum beta lactamase and metallo beta lactamase producers among multidrug resistant Escherichia coli and Klebsiella spp. in urinary tract infections

: The incidence of Urinary tract infection (UTI) concomitantly causing the morbidity and mortality in patients with specific risk factors is highly alarming. () and spp., are the most frequently isolated species and considered as highly significant due to their ability to produce Extended spectrum beta lactamase (ESBL) and Metallo beta lactamase (MBL). UTIs caused by bacteria that produces ESBL and MBL are becoming more common, and the ability of diagnostic microbiology laboratories to promptly screen for and identify these resistant infections is crucial.The main objective of my study is to identify and its susceptibility pattern of ESBL and MBL producing and spp., causing UTI.: A total 0f 200 multi drug resistant (MDR) and spp., were screened for ESBL as well as MBL production by phenotypic methods. : From a total of 350 significant UTI cases, 135 are and 65 are spp., remaining are comprised of other bacteria such as Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis. Among 135 isolates 56 found to be multidrug resistant and 42 were ESBL producers and 9 were MBL producers. Among 65 spp., isolates 23 were multidrug resistant and 22 were ESBL producers and 6 were MBL producers.: This study reveals the prevalence of ESBL and MBL producing multidrug resistant and spp., in urinary tract infections as well as their significant role in treatment failure.

Ceftazidime-avibactam in the treatment of bacteremia due to carbapenem-resistant gram-negative bacteria in hematological patients: Experience in a single center

IntroductionLimited experience exists with ceftazidime-avibactam (CAZ-AVI) in treating bacteremia caused by carbapenem-resistant Enterobacterales (CRE) and Pseudomonas aeruginosa (CRPA) in hematological patients. MethodsWe performed a single-center, retrospective, observational study including patients who received CAZ-AVI for bacteremia due to CRE or CRPA between 2018 and 2022. The primary outcome was 30-day survival. We conducted a multivariable analysis to identify predictors of survival. Results56 patients were included and 57 (41 CRE and 16 CRPA) strains were isolated. 35 strains produced carbapenemase, including 25 metallo-beta-lactamase (MBL) and 10 serine-beta-lactamase. 48 patients (85.7 %) received combination therapy. All patients with MBL-CRE bacteremia (n = 24) received combination therapy with aztreonam (AZT). The susceptibility rates to CAZ-AVI were only 26.8 % (11/41) in CRE and 80.0 % (8/10) in CRPA. The 30-day survival rates were 85.0 % (34/40) in the CRE group and 81.3 % (13/16) in the CRPA group. In patients with MBL-CRE bacteremia, the 30-day survival was as high as 91.7 % (22/24) due to combination with AZT. Ceftazidime did not influence the activity of aztreonam-avibactam against MBL-CRE in-vitro. Multivariable cox analysis revealed neutropenia >14 days (P = 0.002, HR: 34.483, 95%CI: 3.846–333.333) and a higher Pitt bacteremia score (P = 0.005, HR: 2.074, 95%CI: 1.253–3.436) were risk factors for 30-day survival. ConclusionsCAZ-AVI is highly effective in treating bacteremia due to CRPA and serine-beta-lactamase CRE. The combination of avibactam with AZT is highly effective in treating bacteremia due to AZT-resistant MBL producers.

Phenotypic and genotypic detection of Beta-lactamase producing Pseudomonas aeruginosa isolated from Haryana, India

Antimicrobial resistance causes substantial risks to human health globally, and millions of people die worldwide due to multiple drug resistances. Beta-lactam drugs are common for curing infections, and resistance to these drugs cause serious threat to humans. The resistance is acquired by the gram-negative Pseudomonas aeruginosa by producing beta-lactamases such as metallo beta-lactamase (MBL), extended-spectrum beta-lactamase enzymes (ESBL), and AmpC β-lactamases. Hence, this study was intended to detect the occurrence of MBL, ESBL, and AmpC β-lactamases producing P. aeruginosa and to evaluate antibiotic sensitivity at the Pandit Bhagwat Dayal Sharma, Post Graduate Institute of Medical Sciences, Rohtak, Haryana, India. A total of 163 P. aeruginosa were isolated from the different samples of patients, such as urine, blood, sputum, pus, and pleural fluids. The P. aeruginosa was characterized morphologically, biochemically, and with matrix-assisted laser desorption ionization-time of flight mass spectrometry. Their antibiotic sensitivity was evaluated by the Kirby-Baur disc diffusion method. Antibiotic sensitivity tests of P. aeruginosa showed 163/163 were susceptible to Polymyxin-B, 78/163 and 65/163 were resistant against Ceftazidime (CAZ) and IMP antibiotics, respectively. The IMP, CAZ, and cefoxitin-resistant isolates were selected and further evaluated for ESBL, MBL, and AmpC enzyme production. In conclusion, the findings of this study indicated a significant presence of ESBL, MBL, and AmpC enzyme-producing P. aeruginosa among the patients. The ESBL prevalence was much higher in indoor patients than in outdoor patients. The total prevalence of MBL-producing strains in Imipenem-resistant P. aeruginosa (IRPA) was (46/62) 74.19%, which is an alarming signal. There was a higher prevalence of IRPA MBL-producing strains in indoor patients (36/46) 78.6% as compared to outdoor patients (10/16) 62.50%. Identification of bronchoalveolar lavage and sputum was also done using the Biofire Film Array, which revealed the resistant genes, including NDM (20 genes), CTX-M (17 genes), OXA-48-like (9 genes), VIM (5 genes), and IMP (2 genes). Antibiotics like cefotaxime and CAZ have less effect, but carbapenems and aminoglycosides are the best options for treating ESBL-producing P. aeruginosa. Drugs not recommended for treating this pathogen are penicillins and sulfonamides like co-trimoxazoles. Strict infection control measures, careful monitoring of antibiotic administration, and routine screening for ESBL-producing strains are advised before treating the patients.

Emerging Trends of Extended Spectrum BetaLactamase and Metallo-Beta Lactamase Escherichia Coli Strains among Pregnant Women in Mile 4 Hospital, Abakaliki: Implications for Antenatal Care

This investigation assessed the prevalence of extended spectrum beta-lactamase (ESBL) and metallo-beta lactamase (MBL) producing Escherichia coli among seemingly healthy pregnant women attending the antenatal clinic at Mile 4 Hospital in Abakaliki, Nigeria. A total of 100 midstream urine samples were collected and processed using standard microbiology techniques. Antibiotic susceptibility testing was conducted via the disc diffusion method. ESBL and MBL production screening utilized the double disc synergy test and the combined disc test inhibition assay, respectively. The findings demonstrated a 54% prevalence of E. coli among the study participants, with the highest occurrence observed in the third trimester (31.5%) and the lowest in the first trimester (25.9%). Across age groups, prevalence ranged from 9.3% in participants aged ≤20 years to 44.4% in the 21-30 age bracket. Additionally, among participants with varying educational backgrounds, prevalence ranged from 18.5% in uneducated individuals to 33.3% in those with a secondary education. Antibiotic susceptibility of the isolates varied from 0% to 81.5%. ESBL and MBL screening identified 18 (33.3%) and 11 (20.4%) positive isolates, respectively. The antibiotic susceptibility among ESBL-producing E. coli ranged from 0% to 100%, while MBL-positive E. coli showed susceptibility ranging from 0% to 90.5%. The multiple antibiotic resistance index (MARI) ranged from 0.3 to 1.0, with an average of 0.7 among the isolates. This study highlights a substantial prevalence of multidrug-resistant ESBL and MBL-producing E. coli strains among apparently healthy pregnant women. This situation raises concerns about the early exposure of fetuses to multidrug resistance, emphasizing the urgency for proactive measures to address this emerging health risk. Keywords: ESBL positive E. coli, metallo-betalactamase positive E. coli, apparently healthy pregnant women, Abakaliki, Nigeria.

Efficacy of Colistin with Carbapenems Combination by Checkerboard Assay against Carbapenem Resistant Non Lactose Fermenting Gram Negative Bacteria

Recent emergence of carbapenem resistant non-fermenting Gram negative bacteria (CRNFGNB) predominantly Pseudomonas and Acinetobacter species are responsible for significant proportion of nosocomial infections with increased mortality. Of the various mechanisms known, carbapenemases especially metallo beta lactamase (MBL) mediated resistance is the most concerning because of its easy transmissibility via mobile genetic elements and lack of MBL inhibitors for clinical use. In the present study we determined to estimate the prevalence of carbapenem resistant Pseudomonas and Acinetobacter species, their resistance mechanisms by phenotypic tests and synergistic studies with Colistin and carbapenems combination by checkerboard assay. Carbapenem resistance among these two bacteria is 53.2% being isolated predominantly from pus and endotracheal secretions and from patients within the age group of less than 9 years (44%) and more than 60 years (23%). The incidence of carbapenemase and MBL production in NFGNB is 89.8% and 87.9%, respectively. Only Colistin and Tigecycline show significant antibacterial activity while most of the tested antibiotics were found to be least effective against carbapenem resistant NFGNB. Colistin and Imipenem combination demonstrated synergistic activity in majority of the NFGNB species; however, translation of such in vitro efficacy models into highly variable in vivo conditions could be possible only with strong clinical support.

Ceftazidime-avibactam alone or in combination with Aztreonam versus Polymyxins in the management of carbapenem-Resistant Klebsiella pneumoniae nosocomial Infections (CAPRI study): a retrospective cohort study from South India.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections commonly cause hospital-acquired infections. The study aimed to compare the outcomes of CRKP infections between patients receiving ceftazidime avibactam +/-aztreonam and polymyxins in a hospital setting with a high prevalence of New Delhi Metallo Beta Lactamase production. We conducted a retrospective cohort study from January 2020 to September 2022 in critically ill adult patients admitted to a non-COVID-19 medical intensive care unit with CRKP infection. The patients were followed up for a total of 30days or death, whichever was later. Of a total of 106 patients included in the study, 65 patients received polymyxins and 41 patients received ceftazidime-avibactam +/- aztreonam. Higher 30-day mortality was noted in the polymyxin group (56.9% vs. 29.2%, P = 0.005). The mean time to event (mortality) in ceftazidime-avibactam +/- aztreonam was 23.9 + 1.5days which was significantly higher compared to polymyxins (17.9 + 1.2days, p = 0.006). On Cox regression analysis, after adjusting for the covariates, the hazard ratio for time to event with the use of polymyxin was 2.02 (95% CI: 1.03-3.9). Ceftazidime-avibactam + aztreonam is possibly associated with better clinical outcomes in patients infected with CRKP.

COMPARISON OF DOUBLE-DISC SYNERGY, COMBINED DISC DIFFUSION, AND E TEST FOR METALLO-BETA-LACTAMASE DETECTION IN PSEUDOMONAS AERUGINOSA IN A TERTIARY CARE HOSPITAL

Objective: Pseudomonas aeruginosa is an important opportunistic pathogen associated with nosocomial infections. The metallo-beta-lactamases (MBLs) are an important class of carbapenemases which are predominantly produced by P. aeruginosa. This study is aimed to study the prevalence of MBLs among imipenem (IMP)-resistant P. aeruginosa and to evaluate three different methods of screening and detecting MBLs produced by P. aeruginosa. Methods: 100 isolates of P. aeruginosa were obtained from various clinical specimens, including pus, wound, sputum, urine, body fluids, and ET tips received at the laboratory from July 2021 to December 2021. Screening for MBL production among IMP-resistant P. aeruginosa was done by double-disc synergy test and combined disc test. Confirmation of MBL production was done by E-test. Results: Of the 100 P. aeruginosa isolates, 16 were IMP resistant, of which 16 are MBL producers. Most of the samples were obtained from 50 to 60 years followed by 40–50 and 60–70 were pus (50%) followed by sputum (20%), urine (15%), and body fluids (5%). Of the 100 isolates, 66 were isolated from females and 34 from males. Pus samples showed most MBL-producing isolates, accounting for 60.5%. MBL producers accounted for 90% of IMP-resistant cases using combined disc method and 100% using MBL E-strip test. By comparison, double-disc synergy test (DDST) retrieved 45% of Pseudomonas MBL producers. Conclusion: This study found moderate prevalence of Pseudomonas MBL producers (16/100). The study supports the use of combined disc-diffusion test and DDST for screening and confirming MBL producers of P. aeruginosa by E test where polymerase chain reaction is not available.

Comparison of Prevalence of blaNDM-1 Gene among Metallo-Beta Lactamase-Producing Multidrug-Resistant Fermenters and Nonfermenters in a Tertiary Care Hospital

Background and Aim: Metallo-beta-lactamases (MBLs) which open β-lactam ring with help of metal cofactor degrade all the classes of β-lactams except monobactams and are notable for their constant and efficient carbapenemase activity. New Delhi Metallo-beta-lactamase (NDM) is type of carbapenemase which is able to inactivate all β-lactams except aztreonam. Combined disk synergy test (CDST) and polymerase chain reaction (PCR) analysis are used for the detection of MBL production. Materials and Methods: All clinical specimens received in the microbiology department for culture and sensitivity from indoor patients were included in study. Brief history and related data of the patients was being recorded. The direct Gram staining and samples were inoculated on culture media and incubated at 37°C for 18–24 h. Biochemical reactions were performed and the antibiotic susceptibility test was performed by Kirby–Bauer Disk-Diffusion method and VITEK 2. All the multidrug-resistant (MDR) Gram-negative bacteria (GNB) which were carbapenem resistant subjected to CDST and Genotypic detection of NDM-1 by PCR was done. The association between categorical variables was explored using the Pearson’s Chi-square test. Results: The present study was conducted on 260 GNB isolated from 5307 specimens, 164 were MDR, 68 were carbapenem resistant, and 48 were found to be MBLs (19 were fermenters; 29 were nonfermenters). Thirty-six blaNDM-1 gene was isolated from both MDR fermenters and nonfermenters. The positivity of CDST in detecting blaNDM-1 positive MBLs taking PCR as the gold standard was 75%. Conclusion: NDM-1 carrying isolates disseminate quickly even among the organisms of different genera, their presence in high proportion could further threaten the public health and put an end to our current pharmacopoeia.

Extended-Spectrum Beta-lactamase and Metallo-beta-lactamase Production among Escherichia coli and Klebsiella pneumoniae Strains from Urine of Pregnant Women in Afikpo, Ebonyi State, Nigeria

Aim: The aim of this study was to determine the occurrence of Extended-spectrum beta-lactamase (ESBL) and Metallo-beta-lactamase (MBL) among Escherichia coli and Klebsiella pneumoniae strains from pregnant women attending Mater Misericordia Hospital Afikpo, Ebonyi state, Nigeria.
 Study Design: This is a laboratory based prospective study carried out on pregnant women suspected of having urinary tract infection and was requested to undergo diagnosis at microbiology laboratory of the hospital.
 Place and Duration of Study: The study was conducted in the Department of Science Laboratory Technology, Akanu Ibiam Federal Polytechnic, Unwana, Afikpo, Ebonyi State, Nigeria from October, 2022 to January, 2023.
 Methodology: Clean-catch midstream urine samples were collected from 206 pregnant women suspected of having urinary tract infection and were requested to undergo medical diagnosis at microbiology laboratory of the hospital. The urine samples were processed following standard microbiological procedure. Antimicrobial susceptibility testing was determined using the disc diffusion method, while ESBL phenotypes were determine by the Double-Disc Synergy Test (DDST). Disc potentiation test was performed to check for MBL production.
 Results: Out of the 206 urine samples processed, 24 (11.7 %) E. coli and 12 (5.8 %) K. pneumoniae were isolated. The antimicrobial susceptibility of the isolates recorded a 100 % resistance with Amoxicillin/Clavulanic acid and Cotrimoxazole. The Gram-negative isolates showed a high sensitivity of 100 % to Netilmicin, Meropenem and Ofloxacin. Overall, 35 (97.2 %) multidrug resistance (MDR) was observed of the bacteria isolates. A total of 9 (37.5 %) E. coli and 4 (33.3 %) K. pneumoniae was found positive for ESBL production whereas, 5 (20.8 %) E. coli and 2 (16.7 %) K. pneumoniae were MBL positive.
 Conclusion: The level of drug resistance in this study underscores the need for regular surveillance for effective management of urinary tract infection in pregnancy.

Isolation and Speciation of Acinetobacter Species with Special Reference to Antibiotic Resistance in Tertiary Care Hospital

Acinetobacter can survive longer in the environment and is also known for developing resistance against agents like disinfectants and nutritional deprivation. Very restricted information about Acinetobacter is available because of their confused taxonomic status. The isolation and identification of resistance pattern help in the selection and search for new antibiotics, reducing the morbidity and mortality of patients. The present study was conducted to find the different types of resistant mechanisms in Acinetobacter species and their antimicrobial susceptibility pattern from various clinical samples. Gram's stain and biochemical reactions identified Acinetobacter isolated from various clinical samples. Antibiotic susceptibility testing was done, and their resistant pattern was observed. Phenotypic methods for drug resistance were carried out -Detection of Extended Spectrum Beta Lactamase (ESBL) by Double disc synergy test (DDST), detection of Metallo Beta Lactamase (MBL) by Imipenem with EDTA, and detection of Carbapenemase production by Modified Hodge test (MHT). The results showed that out of 150 isolates of Acinetobacter species, Acinetobacter baumannii 138 (92%) was the most common species isolated, followed by Acinetobacter lwoffii 10 (7%) and Acinetobacter hemolytic 2 (1%). Of these, 22 (15%) isolates showed ESBL production by Double disc synergy test, 80 (53%) isolates were MBL producers, and 11 (7%) were Carbapenemase producers by Modified Hodge test. The study observed that ESBL production in Acinetobacter was 22(15%) and MBL 80(53%). It demonstrated that most of the Acinetobacter isolated were found to be Multi-Drug Resistant (95%). It brings out the need for active surveillance combined to eradicate the curtail of this organism in hospital settings.

Phenotypic detection of multi-drug resistant MBL-producing Gram-negative bacteria isolated from clinical samples of patients in hospitals in Akwa Ibom State, Nigeria

Metallo-beta-lactamase (MBL)-producing Gram-negative bacteria (GNB) continue to be a bane in the treatment of clinical infections in both community and hospital settings. Prompt detection of multidrug resistant (MDR) strains using antimicrobial susceptibility testing (AST) and MBL detection are vital for therapeutic options. The aim of this study was to determine the prevalence, distribution and antibiotic susceptibility of MDR and MBL-producing GNB from clinical samples in health facilities in Akwa Ibom State. A total of 480 samples comprising wound, urine and blood were collected aseptically from eligible in- and out-patients for the study and GNB were recovered from the samples using standard bacteriological techniques. The identification of isolated GNB, AST and detection of MBL-producing GNB were done using VITEK®2 COMPACT (Biomerieux) automated system, Modified Kirby Bauer disc diffusion method and IMP+EDTA CDT phenotypic method, respectively. Gram-negative bacterial growth was detected in 135 (77.1%.) cases with Escherichia coli (20.7%), Klebsiella pneumoniae (17.8%) and Burkholderia cepacia (14.1%) being the most preponderant isolates. Urine yielded more GNB, 45.2% than other samples. The isolates were sensitive to gentamicin (63%), imipenem (54.8%), and ofloxacin (46.7%) but showed high resistance to sulfamethoxazole-trimethoprim (78.5%), ceftriaxone (74.1%) and aztreonam (66.7%). The overall prevalence of MDR was 60% with the highest recorded in University of Uyo Teaching Hospital (UUTH), 64.8%. The overall prevalence of MBL producers was 39.3% with H. alvei, M. morgannii, P. mirabilis, R. radiobacter and P. aeruginosa being the majority, mostly from urine samples (47.5%) and UUTH health facility (43.7%). All MBL-producing GNB were MDR strains. Seven strains were pan-drug resistant. A combination of robust antibiotic and MBL screening of drug resistant GNB is essential for effective therapeutic decisions. Also, rational use of antibiotics, review of antibiotic usage policies and increased surveillance of MBL-producing GNB is strongly advocated.