Modified Hodge Test Research Articles

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 and molecular methods of carbapenemase detection: Can we break the chain and preserve the carbapenems?

BackgroundThe World Health Organization (WHO) has declared antimicrobial resistance (AMR) as one of the top ten public health threats faced by humanity. Carbapenems are currently the last option β-lactam antibiotics for treatment of both hospital and community acquired infections. The rapid rise and spread of carbapenem resistant organisms (CRO) is a global concern highlighting the need for early detection and isolation of patients. MethodsA total of 226 non- repeat, carbapenem resistant Gram-negative isolates were subjected to carbapenemase detection. Three phenotypic methods like Modified Hodge Test (MHT), RAPIDEC® CARBA NP kit (bioMérieux, France) and Chromogenic agar were used and a cartridge based molecular method Xpert® Carba-R (Cepheid) was used on all the study samples for detection of carbapenemases. ResultsThe results of MHT, RAPIDEC® CARBA NP and CHROMagar were same for both Enterobacteriaceae and Non Fermenters (except for CHROMagar, which is applicable only for Enterobacteriaceae). Xpert® Carba R could not detect genes in all the phenotypically positive organisms for carbapenemase production. However, there was no statistically significant difference between the three phenotypic tests and Xpert® Carba R used for the detection of carbapenem resistance. ConclusionPreserving the last resort antimicrobials is the need of the hour, as there are few therapeutic options for treating infections caused by carbapenem-resistant bacteria. Early detection, followed by strict implementation of infection prevention and control strategies to stall the dissemination of such organisms is the best way and needs to be implemented on a war footing.

Prevalence of Carbapenem-Resistant Hospital Acquired Infections and Their Antimicrobial Susceptibility Pattern in a Tertiary Care Hospital

Background: The emergence of antimicrobial-resistant bacteria has become a public threat, creating a burden on medical care in hospitals. Carbapenem-resistant organisms are a source of both community-acquired and healthcare-acquired infection that poses a substantial hazard to public health. This study aimed to conclude the prevalence of carbapenem resistance gram-negative bacteria from a clinical specimen at Index Medical College -Indore.
 Methodology: This study was conducted in the Department of Microbiology, at Index Medical College, Indore, between January 2020 and January 2022.The isolates were subjected to antimicrobial susceptibility tests by Kirby Bauer’s disk diffusion test. Most of the isolates were resistant to beta-lactam drugs, cephalosporin’s and aminoglycosides. These isolates were further confirmedby phenotypic detection usingthe Modified Hodge test, Modified carbapenem Inactivation, Combined disc diffusion test and Double Disk Synergy.
 Results: The percentage distribution of health-associated infection show highest resistance in both urinary tract and respiratory tract infection, followed by skin & soft tissue infection and least in septicemia and other health associated infection. Highest percentage of resistance was seen in the age group between 21-30 and the least in less than 10 years with a statistical significance of p-value=.00001. The most common isolates recover was E.coli in Enterobacterals and in Non fermenter it was Pseudomonas aeruginosa and Acientobacter. The sensitivity of MHT, mCIM, CDDT, and DDST within CI 95% were 74%, 95%, 84%, and 95% respectively. The overall prevalence of carbapenem resistance is 17.75%.
 Conclusion: The production of carbapenemase is the major mechanism underlying carbapenem resistance around the world and represents a great health concern. More knowledge is needed to control resistant genes and resistant organisms and their dissemination. There is an urgent need for global collaboration to plan valid strategies to prevent the spread of carbapenemase and the development of new antimicrobial molecules.

Phenotypic and Genotypic Detection of Carbapenem Resistant Organism Causing Nosocomial Infection in Patients Attending Tertiary Care Hospital

Aims: Nosocomial infections are the leading cause of mortality. ESKAPE organisms are the primary causes of nosocomial infection as these organisms are more or less carbapenem resistant. This study aimed to isolate and identify the etiological agents responsible for causing nosocomial infection and determine the carbapenemase producing organism by phenotypic and genotypic detection.
 Study Design: The study design is cross-sectional study.
 Place and Duration of Study: The study was conducted in the Department of Microbiology, at Index Medical College, Indore, between January 2020 and January 2022.
 Methodology: Total of 246 samples was collected from the patients who develop symptoms after 48- 72 hrs of hospitalization. Samples were processed for identification of etiological agents. Gram negative organisms were selected and further identified for carbapenemase enzyme. Screening was done by Kirby Bauer disc diffusion test and further confirmed by Modified Hodge test, Combined Disc test, Double Disc Synergy Diffusion test and Carbapenem Inactivation method. Genotypic detection was done by using multiplex polymerase chain reaction for KPC, NDM and OXA-48 gene.
 Results: Out of 107-gram-negative organisms, 19 (17.75%) were carbapenem resistant. Among 19 carbapenem resistant GNR, 13% MHT, 15% CCDT, 17% DDST and 17% mCIM were positive. The sensitivity and specificity of MHT, CCDT, DDST, mCIM were 74%/100, 84%/100,95%/100 and 95%/100respectively. The genotypic detection shows highest percentage of blaNDM 74% which is followed by bla OXA-48 31% and blaKPC 26%.
 Conclusion: Hospitals have become the hotspot for various microorganism causing nosocomial infections and are getting carbapenem resistance due to irrational use of antibiotics. Antimicrobial stewardship is one of the effective measures that minimize the resistance. Proper universal precaution can also minimize, spread of resistance in organism. If the last resort drug gets resistant, then it could be challenging for the clinician to treat their patients. Hospitals should have regular HAI meeting and release of antibiogram to know the pattern of these notorious organisms invading infection.

Extended-Spectrum β-Lactamase and Carbapenemase-Producing Gram-Negative Bacteria and Associated Factors Among Patients Suspected of Community and Hospital-Acquired Urinary Tract Infections at Ayder Comprehensive Specialized Hospital, Tigrai, Ethiopia.

Little is known about bacteria that produce extended-spectrum beta-lactamases (ESBLs) and carbapenemase in patients with urinary tract infections (UTIs) in Tigrai, Ethiopia. The aim of this study was to describe the magnitude of ESBL- and carbapenemase -producing gram-negative bacteria among patients suspected of community- and hospital-acquired UTIs at a referral hospital in Tigrai, Ethiopia. A cross-sectional study was conducted at Ayder Comprehensive Specialized hospital from January 2020 to June 2020. A 10-20 mL sample of morning mid-stream and catheter urine was collected from consenting participants. Urine samples were cultured on cysteine lactose electrolyte deficient medium and MacConkey agar, and bacteria were identified using standard microbiological protocols. The Kirby-Bauer disk diffusion method was used for antimicrobial susceptibility testing. The combination disk and modified Hodge tests were used detect ESBL and carbapenemase production, respectively. The data was entered into EPI 3.1 software and analyzed using SPSS version 21. Overall, 67 gram-negative bacteria were recovered from 64 participants. Escherichia coli was the predominant isolate (68.6%), followed by Klebsiella pneumoniae (22.4%), while ESBL production was found in both Escherichia coli and Klebsiella pneumoniae (52.2% and 86.7%, respectively). Isolates recovered from patients with hospital-acquired UTIs were more likely to produce ESBLs (AOR= 16.2; 95% CI: 2.95-89.5). Carbapenemase was produced by 4.3% of E. coli and 20% of Klebsiella pneumoniae isolates. High resistance rates were found against tetracycline (84.8%), ampicillin (78.3%), amoxicillin/clavulanic acid (58.7%) for Escherichia coli isolates and against ampicillin (93.3%), sulphamethexazole trimethoprim (93.3%), cefotaxime (86.6%), and ceftazidime (86.6%), and tetracycline (73.3%) for Klebsiella pneumoniae. Most UTIs were caused by ESBL-producing bacteria, especially those that were related to healthcare. Microbiological-based therapy for patients with UTIs is essential at our study site due to high rates of ESBL and significant carbapenemase production with concomitant high rates of drug resistance to several antibiotics.

Molecular Detection of Carbapenem Resistance in Clinical Isolates of Klebsiella pneumoniae in Tertiary Care Hospital

Antibiotic resistance has become a serious global threat, mainly due to misuse, overuse of antibiotics and non-compliance with infection control protocol. Superbugs are multidrug-resistant (MDR) and extended drug-resistant (XDR) bacteria, mainly Klebsiella pneumoniae and Escherichia coli from the Enterobacteriaceae family, which cause opportunistic infections and raise death rates and hospital expenditures. The present study was conducted at a tertiary care teaching hospital to study the epidemiology and molecular detection of carbapenem-resistant K. pneumoniae isolated from various clinical specimens. 240 K. pneumoniae isolates were collected from January 2020 to December 2021 at the Bacteriology laboratory, Index Medical College and Hospital, Indore. All isolates were analyzed for carbapenem resistance by the conventional disc diffusion method. All carbapenem-resistant isolates were tested for carbapenemase production using the phenotypic double-disk synergy test (DDST) and modified Hodge test (MHT) as per 2020 CLSI guidelines. All isolates were negative by phenotypic methods, further confirmed by conventional PCR to detect the gene responsible for carbapenemase production. 240 isolates of K. pneumoniae were included during the study periods. Out of 240 isolates, 102 isolates were found resistant to carbapenem drugs. All 102 isolates were confirmed carbapenemase and MBL producers by MHT and DDST tests. Among 102, 60 isolates were found to be MBL producers negative by MHT and DDST tests. Sixty phenotypic negative carbapenem-resistant isolates were tested by conventional PCR. One or more carbapenemase genes were detected in 61.0% of isolates. The blaKPC was detected in 13/60 (21%) isolates, followed by blaNDM 10/60 (16%) isolates, followed by blaVIM in 6/60(10%), blaOXA-48 in 5/60 (8%) and blaIMP in 3/60(5%) isolates. K. pneumoniae produces carbapenemase, which enhances resistance to the carbapenem class of antibiotics. The simultaneous detection of these resistance genes expressed by Klebsiella pneumoniae might be managed by early detection and adhering to antibiotic policies that limit the use of antibiotics.

BACILOS GRAM NEGATIVOS RESISTENTES A CARBAPENÉMICOS PRODUCTORES DE CARBAPENEMASAS AISLADOS DE PACIENTES DEL HOSPITAL BELÉN DE TRUJILLO

The inappropriate use of carbapenems in recent decades has begun to lead to an increase in carbapenem-resistant Gram-negative bacilli. Within the mechanisms of resistance, the synthesis of carbapenemases is the most relevant.The objective was to detect the presence of carbapenemases in Gram-negative bacilli resistant to carbapenems isolated from patients of the Belen de Trujillo hospital during the months of July 2018 to July 2019, the cultures were determined by the Modified Hodge Test, as well as the Synergy Test with Boronic Phenyl Acid for the detection of serinocarbapenemases and the Disc Approximation method for the detection of metallocarbapenemases. It was determined that of the total carbapenem resistant found a little more than half were likely producers of carbapenemases being the Serincarbapenemases the most frequently found and Pseudomonas aeruginosaand Acinetobacter baumaniiare the bacilli most frequently found as carbapenemase producers.

Prevalence and Phenotypic Detection of Carbapenem-Resistant Enterobacter Species from the Clinical Specimens of a Tertiary Care Hospital in Bangladesh

Background: Carbapenem-resistant Enterobacter (CRE) is an emerging threat spread rapidly around the world in the past few years, posing substantial hazards to human health. Objective: The study was conducted to evaluate the prevalence of carbapenem resistance and to detect carbapenemase producers phenotypically from patients of a major tertiary care hospital, in Bangladesh. Methods: Prospective cross-sectional study was conducted from July 2018 to June 2019, at the Dhaka Medical College hospital. Patients admitted to different wards, and intensive care units, visited the outpatient department, and samples received in the microbiology department were included in this study. A total of 350 clinical samples were collected, inoculated, and incubated in accordance to the standard protocol. Identification was done using the standard biochemical method. Antimicrobial susceptibility testing of commonly used antibiotics including imipenem was done using Kirby Bauer disk diffusion method. All the clinical isolates of Enterobacter were screened for carbapenem resistance as per CLSI guidelines. Such strains were then subjected to phenotypic confirmation of carbapenemase production by the Modified Hodge test. All isolates that gave a positive screening test were further evaluated for Metallo-β lactamase (MBL) production. MBL was further detected by Combined Disc Test (CD) using a combination of Imipenem and Imipenem-EDTA and double disc synergy (DDS) test. Result: A total of 350 clinical specimens were analyzed, of which 224 (65.14%) isolates yielded growth. Among them, 28 (12.28%) Enterobacter were isolated of which 12 (42.86%) were found to be Imipenem resistant (14.25%) and were labeled 'Carbapenem-resistant Enterobacter" or CRE. Minimum inhibitory concentration (MIC) was determined among the carbapenem-resistant clinical isolates. Modified Hodge test (MHT) performed on the 12 carbapenem-resistant isolates showed 9 (75%) isolates to be carbapenemase enzyme producers. Nine out of twelve carbapenem-resistant isolates are Metallo-beta-lactamase producers detected by combined disc test (CDT) and eight (66.67%) MBL producers detected by DDS test. Conclusion: The finding from this study revealed a high prevalence of carbapenem resistance among isolated Enterobacter species in hospital settings as well as community levels. As there are limited treatment regimens, therefore, the timely and accurate detection of carbapenem-resistant Enterobacter species is essential for the clinical treatment and prevention of infections. Simple phenotypic methods like MHT can be used for the rapid detection of carbapenemases, and these are expected to be used routinely in clinical microbiology laboratories. Update Dent. Coll. j: 2023; 13(1): 17-22

Carbapenemase detection methods for carbapenem-resistant Enterobacterales: Which to choose?

Abstract Background: Carbapenems are among the last resorts in managing multidrug-resistant bacterial infections. The rise in resistance to carbapenems is a significant concern, and the production of carbapenemases that inactivate the drug is the most typical mode of resistance developed by the bacteria. Carbapenemase-producing bacteria are associated with higher morbidity and spread faster than noncarbapenemase-producing bacteria. Detection of carbapenemases is essential for epidemiological surveillance and in choosing the most efficient antimicrobial in managing the patient. Materials and Methods: We processed urine samples received in our laboratory over 6 months. Samples with carbapenem-resistant Enterobacterales were further processed for carbapenemase detection using the modified carbapenem inactivation method (mCIM), combined disc diffusion test (CDDT), Epsilometer test (E test), and modified Hodge test (MHT). The results were analyzed. Results: A total of 32.3% of Enterobacterales uropathogens showed resistance to imipenem/meropenem. The commonest isolate was Escherichia coli, followed by Klebsiella pneumoniae. Maximum positivity was detected by mCIM (89.2%) followed by CDDT (86.5%), E test (77.1%), and MHT (54%). Conclusion: In this study, we compared four phenotypic methods of carbapenemase detection and compared their diagnostic accuracy. These included CDDT, E test, MHT, and mCIM. Maximum positivity was detected by mCIM followed by CDDT and E test.

Investigation of antimicrobial resistance patterns and molecular typing of Pseudomonas aeruginosa isolates among Coronavirus disease-19 patients

BackgroundPseudomonas aeruginosa is a common co-infecting pathogen recognized among COVID-19 patients. We aimed to investigate the antimicrobial resistance patterns and molecular typing of Pseudomonas aeruginosa isolates among Coronavirus disease-19 patients.MethodsBetween December 2020 and July 2021, 15 Pseudomonas aeruginosa were isolated from COVID-19 patients in the intensive care unit at Sina Hospital in Hamadan, west of Iran. The antimicrobial resistance of the isolates was determined by disk diffusion and broth microdilution methods. The double-disk synergy method, Modified Hodge test, and polymerase chain reaction were utilized to detect Pseudomonas aeruginosa extended spectrum beta-lactamase and carbapenemase producers. Microtiter plate assay was performed to evaluate the biofilm formation ability of the isolates. The isolates phylogenetic relatedness was revealed using the multilocus variable-number tandem-repeat analysis method.ResultsThe results showed Pseudomonas aeruginosa isolates had the most elevated resistance to imipenem (93.3%), trimethoprim-sulfamethoxazole (93.3%), ceftriaxone (80%), ceftazidime (80%), gentamicin (60%), levofloxacin (60%), ciprofloxacin (60%), and cefepime (60%). In the broth microdilution method, 100%, 100%, 20%, and 13.3% of isolates showed resistance to imipenem, meropenem, polymyxin B, and colistin, respectively. Ten (66.6%) isolates were identified as multiple drug resistance. Carbapenemase enzymes and extended spectrum beta-lactamases were identified in 66.6% and 20% of the isolates, respectively and the biofilm formation was detected in 100% of the isolates. The blaOXA-48, blaTEM, blaIMP, blaSPM, blaPER, blaVEB, blaNDM, blaSHV, and blaCTX-M genes were detected in 100%, 86.6%, 86.6%, 40%, 20%, 20%, 13.3%, 6.6%, and 6.6% of the isolates, respectively. The blaVIM, blaGIM, blaGES, and blaMCR-1 genes were not identified in any of the isolates. The MLVA typing technique showed 11 types and seven main clusters and most isolates belong to cluster I, V and VII.ConclusionDue to the high rate of antimicrobial resistance, as well as the genetic diversity of Pseudomonas aeruginosa isolates from COVID-19 patients, it is indispensable to monitor the antimicrobial resistance pattern and epidemiology of the isolates on a regular basis.

Molecular Characterization and Epidemiology of Carbapenem-Resistant Enterobacteriaceae Isolated from Pediatric Patients in Guangzhou, Southern China.

Carbapenem-resistant Enterobacteriaceae (CRE) are spreading worldwide, posing a serious public health concern. However, the data on CRE strains that cause infections in children in Guangzhou remain limited. Therefore, this study aimed to investigate the epidemiology of CRE, drug resistance, and resistance mechanisms in children in Guangzhou, Southern China. In total, 54 nonrepetitive CRE strains were collected in pediatric patients at three centers in Guangzhou, Southern China, from January 2016 to August 2018. CRE isolates were used for further studies on antimicrobial susceptibility, the modified Hodge test (MHT), the modified carbapenem inactivation method (mCIM), and drug resistance genes. Multilocus sequence typing (MLST) was used to elucidate the molecular epidemiology of K. pneumoniae. The isolated CRE strains include 34 K. pneumoniae (63.0%), 10 E. coli (18.5%), 4 Enterobacter cloacae (7.4%), and 6 Proteus mirabilis (11.1%) strains. The strains were isolated mainly from the blood (31.5%, n = 17), sputum (31.5%, n = 17), and urine (16.7%, n = 9). All CRE isolates were highly resistant to the third- or fourth-generation cephalosporins, carbapenems, and β-lactam + β-lactamase inhibitors (94.4%-96.3%). In addition, the resistance rates to amikacin, ciprofloxacin, levofloxacin, tigecycline, and colistin were 5.6%, 14.8%, 16.7%, 9.3%, and 0%, respectively. Carbapenemase was detected in 35 (64.8%) of the CRE isolates. The most dominant carbapenemase gene was bla NDM (n = 17, 48.6%), followed by bla IMP (n = 13, 37.1%) and bla OXA-23 (n = 4, 11.4%). Other carbapenemase genes (bla KPC, bla sim, bla Aim, bla GES, bla Gim, bla OXA-2 , and bla OXA-48 ) and the mcr-1 gene were not detected. MLST analysis showed high diversity among the K. pneumoniae, and ST45 (11.7%, 4/34) was the dominant sequence type. This study revealed bla NDM was the most dominant carbapenemase gene in children in Guangzhou. Infection control measures need to be taken for the prevention and treatment of CRE infections.

Meropenem in combination with baicalein exhibits synergism against extensively drug resistant and pan-drug-resistant Acinetobacter baumannii clinical isolates in vitro.

Several studies have demonstrated that the effectiveness of carbapenems against drug-resistant Acinetobacter baumannii infections has been decreasing. Combination therapy with two or more drugs is currently under investigation to overcome the emerging resistance against carbapenems. In this study, we tested the possible synergistic interactions of a potent antibacterial flavonoid, baicalein, with meropenem to illustrate this duo's antibacterial and antibiofilm effects on 15 extensively drug resistant or pan-drug-resistant (XDR/PDR) A. baumannii clinical isolates in vitro. Isolates included in the study were identified with MALDI-TOF MS, and antibiotic resistance patterns were studied according to EUCAST protocols. Carbapenem resistance was confirmed with the modified Hodge test, and resistance genes were also analyzed with genotypical methods. Then, checkerboard and time-kill assays were performed to analyze antibacterial synergism. Additionally, a biofilm inhibition assay was performed for screening the antibiofilm activity. To provide structural and mechanistic insights into baicalein action, protein-ligand docking, and interaction profiling calculations were conducted. Our study shed light on the remarkable potential of the baicalein-meropenem combination, since either synergistic or additive antibacterial activity was observed against every XDR/PDR A. baumannii strain in question. Furthermore, the baicalein-meropenem combination displayed significantly better antibiofilm activity in contrast to standalone use. In silico studies predicted that these positive effects arose from inhibition by baicalein of A. baumannii beta-lactamases and/or penicillin-binding proteins. Overall, our findings highlight the prospective potential benefits of baicalein in combination with meropenem for the treatment of carbapenem-resistant A. baumannii infections.

Risk Factors and Prevalence of Mother to New-Born Transmission of Carbapenemase Producing Enterobacteriaceae in Two Hospitals in Yaounde, Cameroon

Background: In African countries, where the burden of neonatal sepsis is the highest, the spread of Carbapenemases Producing Enterobacteriaceae (CPE) in the community, potentially contributing to neonatal mortality, is a public health concern. The transmission routes are not well defined, particularly the possible key role played by pregnant women. The aim of this study was to understand the neonatal acquisition of CPE in Yaounde, Cameroon. Methods: A transversal analytical study was conducted in an urban area. Maternal stool samples during delivery and the first stool from their new-born were collected and cultured to isolate Enterobacteria. After isolation, characterization using API20E identification system, and antibiotic susceptibility testing were performed according to the Antibiogram Committee of the French Society of Microbiology. Carbapenemases detection was done on each carbapenem-resistant strain using the Modified Hodge Test (MHT) and their classification using the synergy tests with different inhibitors. Results: Out of the 55 CPE isolates identified, Escherichia coli was the most encountered bacteria both in mothers (n = 18, 50.00%) and infants (n = 11, 57.89%). Class B and D carbapenemases were found both in mothers and infants. The estimated prevalence of vertical transmission in our study, was 10% (n = 12). Logistic regression showed that CPE carriage in mothers and CPE acquisition in their new-borns were independently associated with the presence of greenish amniotic fluid (OR = 7.33, p 0.0001 in mothers and OR = 4.09, p = 0.0086 in new-borns). Conclusion: Our results highlight the non-negligeable role played by pregnant women in the neonatal acquisition of CPE.

A systematic review of the current status of carbapenem resistance in Nigeria: Its public health implication for national intervention.

Carbapenem antibiotics are considered one of the most effective and the last-resort antibiotics for the treatment of infections caused by multidrug-resistant Gram-negative bacteria. However, with the advent of carbapenem resistance, it becomes obvious that quality health-care delivery will be hampered if adequate measure is not put in place. This review assessed the prevalence of carbapenem-resistant Gram-negative bacteria (CR-GNB) and also provided an up-to-date position on carbapenem resistance (CR) in Nigeria. Three electronic databases (Google Scholar, PubMed and African Journal online) were searched for relevant literatures, and 38 articles published between January 2013 and June 2022 that met the criteria for inclusion were recruited into the study. The mean prevalence of CR in Nigeria stands at 21.3%, with the southern and northern regions documenting a mean prevalence of 22.0% and 20.9%, respectively. Most of the reviewed articles were from clinical settings (81.6%), with urine samples (38.7%) constituting the most prevalent clinical sample in which CR-GNB were detected. The preponderance of phenotypic methods (55.3%) over molecular method (44.7%), particularly the use of disk diffusion test breakpoint and Modified Hodge test was documented. The most prevalent carbapenem-resistant bacteria were Escherichia coli (50.0%) and Klebsiella pneumoniae (26.3%). The blaNDM and blaVIM were the major reported carbapenemase-encoded genes, particularly among E. coli, K. pneumoniae and Pseudomonas species. This systematic review revealed a mean prevalence of CR-GNB in Nigeria that required urgent attention. Furthermore, the detection of clinically and epidemiologically important carbapenemase coding genes is of public health importance.

Horizontal Transfer of Plasmid Mediated Carbapenem Resistant Genes from Klebsiella pneumoniae to Escherichia coli

Carbapenem resistance among Enterobacteriaceae is an emerging problem worldwide. Klebsiella pneumonia carbapenemase (blaKPC) enzymes are amongst the most common beta-lactamases that have been studied. This broad group of organisms with various resistance mechanisms is associated with increased lengths of hospitalization, costs of medical care, morbidity, and mortality. The global spread of Carbapenem Resistance Enterobacteriaceae (CRE) has largely been attributed to disseminating a dominant strain of Klebsiella pneumoniae producing a serine beta-lactamase, termed as Klebsiella pneumonia carbapenemase (KPC). This study was designed to determine in vitro efficacy of horizontal transfer of plasmid-mediated carbapenem-resistant genes from Klebsiella pneumoniae to Escherichia coli. A total of 30 gram-negative rods from different clinical samples were taken. After preliminary antimicrobial susceptibility screening, isolates that showed a resistance zone were included in the study. These isolates were then subjected to the Modified Hodge test for confirmation of carbapenemase production. Out of 10 isolates, four were positive for carbapenemase production. The plasmid from these resistant strains was transformed into DH5α. RFLP analysis was carried to evaluate these transgenic cells resulted in horizontal gene transfer of resistant plasmid DNA from Klebsiella pneumoniae to Escherichia coli.

Detection of Multidrug-Resistant Gram-Negative Organisms in Lagos state Public Hospitals environmental surfaces

Background: Hospital-acquired infections constitute a significant challenge to patient safety due to the emergence of multidrug-resistant (MDR) organisms. Multidrug-resistant (MDR) Gram-negative bacteria have proved to be one of the major leading causes of hospital-acquired infections linked to high morbidity and mortality. The hospital environment serves as a reservoir for MDR bacteria. This study, therefore, investigates the burden of MDR Gram-negative bacterial infections from the hospital environment. Methods: This was a cross-sectional study. Two hundred swab samples were collected from different environmental sources at four public hospitals environment in Lagos, Nigeria. Samples were cultured on 5% blood agar and MacConkey agar (OXOID). Isolates were identified with biochemical tests and confirmed using the VITEK 2 System with the VITEK 2GN identification card (bioMe´rieux, Durham, NC), following the manufacturer’s directions. Antimicrobial susceptibility testing was performed using the Kirby Bauer disk diffusion technique. Extended-spectrum beta-lactamase (ESBL) was detected with the double-disk synergy test. A Modified Hodge test was used to detect carbapenemase production. Multidrug resistance was inferred from resistance to three classes of antibiotics. Results: Fifty-nine bacterial isolates were recovered from hospital environmental samples. Thirty (50.8%) were Gram-negative, while 49.2% were Gram-positive. Klebsiella pneumoniae (40%), Escherichia coli isolates (36.7%), Pseudomonas aeruginosa (10%), Acinetobacter baumannii (6.7%) and Proteus mirabilis (6.7%) were isolated. Twenty (66.7%) isolates were multidrug-resistant to three classes of antibiotics. Nine different antibiotic resistance patterns were observed, and five were characterized as multi-drug resistant. Nineteen isolates (63%) produced ESBL, and 27 (90%) were resistant to meropenem, with 6.7% positive for carbapenemase. Conclusion: Inanimate surfaces are a major environmental reservoir for MDR Gram-negative bacteria in healthcare facilities..

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

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. 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. 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. 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.

Phenotypic Detection of Carbapenem Resistance in Clinical Isolate of Klebsiella Pneumoniae in Tertiary Care Hospital

The emergence and rapid spread of Multidrug resistant isolates of Klebsiella pneumoniae causing nosocomial infections, which require the great afford for the treating the patients by the clinician. The emergence of Metallo β-lactamase (MBL) producing isolates poses a challenge to routine microbiology laboratories. The purpose of this study was to assess the accuracy of various phenotypic methods for detecting MBL production among K. pneumoniae isolate. The current study may provide the necessary data to formulate a hospital antibiotic policy and to prevent the spread of multidrug resistance in the community. Total 240 K. pneumoniae isolates were included in our study which was isolated from various clinical samples from patients visiting a tertiary care hospital in central India. A total of 148 (61.7%) of K. pneumoniae were isolated from male patients whereas 92 (38.3%) isolates were from female patients. Out of 240 K. pneumoniae, 102 (42.5%) was detected Imipenem resistance by conventional (Kirby-Bauer) disc diffusion method which was confirmed by minimum inhibitory concentration (MIC) test (Epsilometer test). By the MIC Carbapenem resistance K. pneumoniae were confirmed for MBL producer by using phenotypic test. Combined disc synergy test (CDST) (Imipenem 10 mcg and Imipenem 10mcg + 0.5 m EDTA) and Modified Hodge test (MHT).The MHT test found most sensitive approach for detecting MBL in K. pneumoniae. This procedure is simple and clear and it may use in routine clinical labs for detection of MBL because carbapenems are last resort for treating bacterial infections. In recent years, carbapenem resistance has rampantly increased across the globe.

Detection of the blaVIM-2 Gene in Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates in Sudan

Background: Acinetobacter baumannii is a pleomorphic aerobic Gram-negative bacillus that is notorious for having multidrug resistance traits. Carbapenem-resistant Acinetobacter baumannii (CRAB) is a global concern due to its ability to retain and disseminate resistance genes, which poses a threat to the spread of resistance among bacterial communities in hospital settings. The aim of our study was to evaluate the existence of the blaVIM-2 gene in carbapenem-resistant Acinetobacter baumannii clinical isolates from Sudanese hospitals. Methods and Results: Forty clinical isolates of Acinetobacter baumannii were collected from June 2021 to April 2022. All isolates of Acinetobacter baumannii were identified via BioMérieux's Vitek-2 automated system (Marcy l'Étoile, France) and evaluated for phenotypic resistance to carbapenem, using imipenem and meropenem. The enzymatic mode of resistance was assessed by the Modified Hodge test (MHT). A real-time PCR was used to detect the presence of the blaVIM-2 gene. Of 40 isolates, 32(80%) were resistant to imipenem, 4(10%) were moderately resistant, and 4(10%) were susceptible to imipenem; 24(60%) were resistant to meropenem, 10(25%) were moderately resistant, and 6(15%) were susceptible to meropenem. MHT was 70% positive with imipenem use and 55% positive with meropenem use. Real-time PCR revealed that only 30% of the samples were positive for the blaVIM-2 gene. All blaVIM-2-positive isolates were resistant to both imipenem and meropenem. Conclusion: Resistance to carbapenem poses a serious threat, denying patients treatment options. It is essential to make continuous surveillance of these strains to prevent the development of resistant strains.

Antibacterial Activity of Lemon Juice on Multi-Drug Resistant Klebsiella species Harboring blaOXA-48 Gene

Klebsiella species cause a wide range of infections, and infections caused by multi-drug resistant species have significantly higher rates of morbidity and mortality. Extended spectrum β-lactamase ESBL prodan emergingd carbapenem resistant K. pneumoniae is emerging problem in hospital settings worldwise. However, the distribution of blaOXA-48 in Klebsiella pneumoniae has rarely been described from Nepal. This study was carried out to evaluate in vitro antibacterial activity of lemon juice against clinical isolates of Klebsiella having blaOXA-48 gene. A total of 667 clinical specimens were processed for the identification of Klebsiella species by morphological, cultural and biochemical tests. Methods of antimicrobial susceptibility testing and confirmation of extended spectrum beta lactamase (ESBL) were adopted from the guidelines of the Clinical Laboratory Standard Institute (2018), and blaOXA-48 gene was detected by polymerase chain reaction. The antibacterial activity of lemon juice was assayed using agar well diffusion, and the bactericidal effect of lemon juice was determined by the broth dilution method. Out of 204 culture positive isolates, 29.5% were Klebsiella species of which 16.7% were ESBL producers. Among 19 isolates positive to Modified Hodge test, 68.4% were detected with the plasmid mediated blaOXA-48 gene. The MIC of lemon juice ranged from 12.5-50% (v/v), and the bacteriostatic activity was observed after 6-8 hours of exposure. The tested varieties of lemon juice showed potential inhibitory activity against Klebsiella species indicating that lemon juice has the potential to be used as an antibacterial agent.