Study of extended spectrum β-lactamase producing Enterobacteriaceae and antibiotic coresistance in a tertiary care teaching hospital

Fecal carriage of extended-spectrum β-lactamase-producing enterobacterales from hospitals and community settings in Gaza Strip, Palestine

BACKGROUND

The fecal carriage of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE) is a major driver of the global spread of these antibiotic resistance determinants. Here we determined the rate of fecal ESBL-PE carriage in pediatric hospitals and community-serving healthcare centers serving adults and children in the Gaza Strip, Palestine.

METHODS

A total of 373 fecal and rectal samples were collected from different hospitals and clinics in Gaza. The antibiotic susceptibility was determined using the disk diffusion method and interpreted according to CLSI guidelines. The bacterial isolates were tested for ESBL production using phenotypic methods (double disk synergy test and growth on selective chromogenic media). BlaCTX-M, blaSHV, and blaTEM genes were sought by PCR.

RESULTS

Out of the 373 isolates tested, 138 (37%) were considered ESBL positive as revealed by phenotypic tests. The prevalence of ESBLs among hospitalized patients was 39.1% (hospital setting) whereas, among outpatients attending community healthcare centers, it was 35.1% (community setting). ESBL production among Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Proteus mirabilis, and Klebsiella aerogenes isolates was 52.8%, 39.1%, 26.7%, 2.8%, and 2.1% respectively. Meropenem and amikacin were the most effective antibiotics against ESBL producers (68.9% and 73.6% susceptibility, respectively), while only 15.2%, 22.5%, and 24.6% remained susceptible to ceftazidime, cefotaxime, and ceftriaxone, respectively. Out of 138 phenotypically ESBL-positive isolates, 98 randomly chosen were screened for blaCTX-M, blaTEM, and blaSHV genes. The prevalence rate of blaCTX-M was 45.9%, while blaTEM and blaSHV genes were detected in 16.8% and 5.2% of CTX-M-negative isolates (corresponding mostly for K. pneumoniae isolates in the case of SHV-PCR), respectively.

CONCLUSIONS

The study revealed an alarmingly high prevalence of fecal carriage of ESBL-producing Enterobacterales among hospitalized children but also in the community of the Gaza Strip. In addition, 30% of ESBL-producers were already resistant to carbapenems, the treatment of choice of infections with ESBL-producers.

Extended-spectrum β-lactamases producing Enterobacteriaceae (ESBL-PE) prevalence in Nepal: A systematic review and meta-analysis

An alarming increase in the occurrence of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) has threatened the treatment and management of bacterial infections. This systematic review and meta-analysis aimed to provide a quantitative estimate of the prevalence of ESBL among the members of the Enterobacteriaceae family by analyzing the community-based and clinical studies published between 2011 and 2021 from Nepal and determine if ESBL-PE correlates with multidrug resistance (MDR). The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed for systematic review and meta-analysis and the articles' quality was assessed using the Newcastle-Ottawa scale. Of the 2529 articles screened, 65 articles were systematically reviewed, data extracted, and included in in-depth meta-analysis. The overall pooled prevalence of ESBL-producers in Enterobacteriaceae was 29 % (95 % CI: 26-32 %) with high heterogeneity (I2 = 96 %, p < 0.001). Escherichia coli was the predominant ESBL-producing member of the Enterobacteriaceae family, followed by Citrobacter spp. and Klebsiella spp. The prevalence of ESBL-PE increased from 18.7 % in 2011 to 29.5 % in 2021. A strong positive correlation (r = 0.98) was observed between ESBL production and MDR in Enterobacteriaceae. ESBL-PE isolates showed high resistance to ampicillin, cephalosporins, and amoxicillin-clavulanic acid, and blaCTX-M type was the most reported gene variant among ESBL-PE. In conclusion, this study demonstrated an increased prevalence of ESBL-PE in Nepal over the last decade, and such isolates showed a high level of MDR against the β-lactams and non-β-lactam antibiotics. Tackling the rising antibiotic resistance (AR) and MDR in ESBL-PE would require concerted efforts from all stakeholders to institute effective infection control programs in the community and clinical settings.

Study of Plasmid-Mediated Extended-Spectrum Beta-Lactamase-Producing Clinical Strains of Enterobacteriaceae From Tabuk Region

BACKGROUND

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae threaten infection treatment globally. This study aims to assess ESBLs-E prevalence and multidrug-resistant organisms (MDR) in clinical specimens from Tabuk, KSA.

METHODS

A cross-sectional research was carried out in March-May 2023. A collective of 90 Enterobacteriaceae isolates were identified from clinical specimens. The specimen was identified by standard methods. The Enterobacteriaceae member was screed for ESBL production by screening and confirmatory as per the Clinical and Laboratory Standards Institute (CLSI).

RESULT

E. coli was the most common isolate, followed by Proteus mirabilis and Citrobacter sp, Klebsiella oxytoca, Klebsiella pneumonia, Proteus vulgaris and Morganella morganii. Among the sample, the majority of isolates were from urine (47.8%) followed by pus (25.6%) and the least from other body fluids (6.7%). The E. coli showed the highest average antibiotic resistance (73.7%) among all the antibiotics used followed by P. mirabilis (70.4%), K. pneumoniae (70%), P. vulgaris (69.8%), M. morganii and Citrobacter (69.4% both), and K. oxytoca (68.8%). There was a 41.2% average reduction in ESBL positivity from phenotypic to confirmatory test results. The highest reduction was observed among M. morganii (66.7%) and the least was observed in E. coli (17.1%).

CONCLUSION

Most of the ESBL-producing isolates were found mainly in blood and urine samples. The most frequent ESBL-producing Enterobacteriaceae were K. pneumoniae and E. coli. The best options for treating Enterobacteriaceae that produce ESBL are Amoxicillin, Amikacin, and Cefoxitin. ESBL-producing isotopes showed a high resistance rate to cefepime and cefotaxime compared to non-ESBL producers. It is of utmost importance to implement reliable infection control measures in healthcare institutions nationwide.

Detection of KPC and VIM Genes in Carbapenem-resistant Klebsiella pneumoniae Isolates from Blood Culture in Southern Anhui, China

Background: Klebsiella pneumoniae is one of the main pathogens of lower respiratory tract infections. Carbapenems are considered the last line of defense for the treatment of Gram-negative bacteria with multidrug resistance. In recent years, with the increase of bacteria producing carbapenemase, the resistance rate of carbapenems has increased gradually. Objectives: The main objective of this study was to detect the blaKPC and blaVIM genes in K. pneumoniae isolates from blood culture specimens. Methods: Within September 2020 to August 2022, 1033 bacterial strains were isolated from blood cultures in Yijishan Hospital of Wannan Medical College, Wuhu, Anhui province, China, including 141 strains of K. pneumoniae. All K. pneumoniae strains were processed for antimicrobial susceptibility testing (AST) using the minimum inhibitory concentration method. Meanwhile, the isolates were phenotypically identified for carbapenemase production by the colloidal gold method. Finally, the confirmed carbapenem enzyme phenotype was further verified for the production of blaKPC and blaVIM by polymerase chain reaction (PCR). Results: Regarding the rate of isolated strains in blood culture, positivity was 11.16% (1033/9255), and the proportion of K. pneumoniae was 13.65% (141/1033). Overall, according to AST results, 7.80% (11/141) of the isolates demonstrated resistance to carbapenems, such as ertapenem, imipenem, and meropenem; nevertheless, they showed sensitivity to colistin and ceftazidime/avibactam. Colloidal gold phenotypically confirmed 81.82% (9/11) of the isolates as carbapenemase producers. Subsequently, nine isolates’ strains were verified to be positive for blaKPC and blaVIM by PCR; the proportions of the blaKPC and blaVIM genes were 88.89% (8/9) and 11.11% (1/9), respectively. Conclusions: The identification of carbapenemase phenotype and genotype is helpful for the accurate understanding of drug resistance and management of the disease.

Phenotypic and genotypic antibiotic susceptibility profiles of Gram-negative bacteria isolated from bloodstream infections at a referral hospital, Lusaka, Zambia

Bloodstream infections (BSI) caused by antimicrobial-resistant (AMR) Gram-negative bacteria (GNB) are a significant cause of morbidity and mortality. Third-generation cephalosporins (3GCs) have been used as empiric treatment for BSI and other invasive infections for years; however, their overuse could promote the emergence of extended-spectrum beta-lactamases (ESBLs). Thus, this study aimed to determine the epidemiological, clinical and microbiological features and the effects of antimicrobial resistance on the outcomes of BSIs at a referral hospital in Lusaka, Zambia. This was a six-month prospective facility-based study undertaken at a referral hospital in Lusaka, Zambia. As part of the routine diagnosis and patient care, blood samples for bacteriological culture were collected from patients presenting with fever and processed for pathogen identification and antimicrobial susceptibility testing using the VITEK 2 Compact instrument. ESBLs and plasmid-mediated quinolone resistance (PMQR) associated genes were determined using the polymerase chain reaction method. Patient information was collected using a structured data collection sheet and entered in CSpro 7.6. Data were analysed in WHOnet and STATA version 14. A total of 88 GNB were isolated, of which 76% were Enterobacterales, 14% Acinetobacter baumannii and 8% Pseudomonas aeruginosa. Resistance to third and fourth-generation cephalosporins was 75% and 32%, respectively. Noteworthy was the high prevalence (68%) of inappropriate empirical treatment, carbapenem resistance (7%), multi-drug resistance (83%) and ESBL-producers (76%). In comparison to E. coli as a causative agent of BSI, the odds of death were significantly higher among patients infected with Acinetobacter baumannii (OR = 3.8). The odds of death were also higher in patients that received 3GCs as empiric treatment than in those that received 4GCs or other (none cephalosporin) treatment options. Structured surveillance, yearly antibiogram updates, improved infection control and a well functional antimicrobial stewardship (AMS) program, are of utmost importance in improving appropriate antimicrobial treatment selection and favourable patient outcomes.

Magnitude and Molecular Characterization of Extended-Spectrum β-Lactamase Genes among Klebsiella pneumoniae Isolates in a Large Tertiary Hospital in Ethiopia

Background Extended-spectrum β-lactamases (ESBLs)-producing Klebsiella pneumoniae is reported worldwide increasingly. However, studies on ESBLs are still scarce in Ethiopia. Therefore, the current study aimed to determine the magnitude and resistance patterns of ESBL-producing K. pneumoniae as well as the frequency of ESBL-encoding genes.Methods A cross-sectional study was conducted from September 2018 to February 2019 at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia among a total of 132 non-duplicate K. pneumoniae isolates. Phenotypic detection of ESBL production was done using Combined Disc Test. ESBL-encoding genes of bla_CTX-M, bla_TEM, and bla_SHV were detected through multiplex PCR.Results The magnitude of ESBL production was 102/132 (77.3%). ESBL positive isolates were 100% resistant to ceftriaxone, cefotaxime, and cefuroxime. Co-resistance of ESBL-positive isolates to other non β-lactam antimicrobials was high to trimethoprim-sulfamethoxazole (96.1%) followed by tetracycline (75.5%) and gentamicin (73.5%). However, these isolates showed high susceptibility to amikacin (96.1%) and meropenem (89.2%). From the total ESBL-positive isolates, 82.6%, 73.5%, and 75% carried bla_CTX-M, bla_TEM, and bla_SHV genes, respectively. The majority 78/102 (76.5%) of ESBL-positive isolates harbored all three types of ESBL genes simultaneously.Conclusions The magnitude of ESBL-producing K. pneumoniae isolates was very alarming in the study area. The co-occurrence of bla_CTX-M, bla_TEM, and bla_SHV genes is high, demanding large-scale studies to evaluate the presence of antimicrobial resistance super-clones. ESBL-producing isolates showed high resistance to most of the antimicrobials, needing phenotypic detection of ESBL regularly for better management of patients.

The Molecular Characterization and Risk Factors of ST131 and Non-ST131 Escherichia coli in Healthy Fecal Carriers in Tehran, Iran

Background: Commensal extended-spectrum β-lactamase (ESBL) producing Escherichia coli isolates in the gut can be the reservoir of virulence factors and resistance genes. Objectives: We investigated the molecular feature, risk factors, and quinolone/fluoroquinolone (Q/FQ) resistance in sequence type 131 (ST131) and non-ST131: ESBL-producing E. coli (EPE) isolates in healthy fecal carriers. Methods: A total of 540 fecal samples and its demographic data were collected from healthy adults in Tehran in 2018. ST131 isolates were identified by MLST analysis, and the characteristics of the virulence factor, phylogenic assay, and Q/FQ resistance genes in ST131 and non-ST131 were determined by polymerase chain reaction (PCR). Results: The EPE isolates mainly belonged to the commensal phylogenetic groups A (54.9%) and D (18.1%). The type 1 fimbriae (fimH; 89.6%) gene was the predominant virulence factor, and there was a significant correlation between ferric yersiniabactin uptake (fyuA; 52.9%), aerobactin receptor (iutA; 17.6%), and group II capsule synthesis (kpsMII; 35.3%) with ST131. In Q/FQ-resistant isolates, qnrS (19%) was the predominant gene, and mutations mostly occurred at codon S83 in GyrA The number of mutations in gyrA and parC genes was significantly higher in ST131 isolates than in non-ST131 isolates. There was a significant positive correlation between diabetes, male gender, and living in the south of the city with EPE carriage (P < 0.05). Conclusions: Accumulation of multiple virulence factors and high- level resistance to Q/FQ in some phylogroups (B2 and D), particularly ST131 isolates, require to be considered in detecting resistant isolates in healthy carriers. According to the risk factor for spreading of EPE isolates (diabetes, living in low-income parts of the city, and male gender), the necessary strategies are required to be developed to control the dissemination of antimicrobial-resistant isolates in the community.

Efficacy and In Vitro Activity of Novel Antibiotics for Infections With Carbapenem-Resistant Gram-Negative Pathogens

Infections by Gram-negative multi-drug resistant (MDR) bacterial species are difficult to treat using available antibiotics. Overuse of carbapenems has contributed to widespread resistance to these antibiotics; as a result, carbapenem-resistant Enterobacterales (CRE), A. baumannii (CRAB), and P. aeruginosa (CRPA) have become common causes of healthcare-associated infections. Carbapenems, tigecycline, and colistin are the last resource antibiotics currently used; however, multiple reports of resistance to these antimicrobial agents have been documented worldwide. Recently, new antibiotics have been evaluated against Gram-negatives, including plazomicin (a new aminoglycoside) to treat CRE infection, eravacycline (a novel tetracycline) with in vitro activity against CRAB, and cefiderocol (a synthetic conjugate) for the treatment of nosocomial pneumonia by carbapenem-non-susceptible Gram-negative isolates. Furthermore, combinations of known β-lactams with recently developed β-lactam inhibitors, such as ceftazidime-avibactam, ceftolozane-tazobactam, ceftazidime-tazobactam, and meropenem-vaborbactam, has been suggested for the treatment of infections by extended-spectrum β-lactamases, carbapenemases, and AmpC producer bacteria. Nonetheless, they are not active against all carbapenemases, and there are reports of resistance to these combinations in clinical isolates.This review summarizes and discusses the in vitro and clinical evidence of the recently approved antibiotics, β-lactam inhibitors, and those in advanced phases of development for treating MDR infections caused by Gram-negative multi-drug resistant (MDR) bacterial species.

Carriage Prevalence of Extended-Spectrum β-Lactamase Producing Enterobacterales in Outpatients Attending Community Health Centers in Blantyre, Malawi

Antimicrobial resistance due to extended-spectrum β-lactamase (ESBL) production by Enterobacterales is a global health problem contributing to increased morbidity and mortality, particularly in resource-constrained countries. We aimed to determine the prevalence of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) in community patients in Blantyre, Malawi. Clinical samples were collected from 300 patients and screened for ESBL-E using a CHROMagar^TM ESBL medium. Confirmation of ESBL production was done by a combination disk test (CDT). The prevalence of community-acquired ESBL-E was 16.67% (50/300, 95% CI = 12.43–20.91%). The most common ESBL-E species isolated was Escherichia coli (66%). All ESBL-E isolates were resistant to Trimethoprim-Sulfamethoxazole except for 2% of E. coli. Besides this, all ESBL-E were susceptible to Imipenem and only 4% were resistant to Meropenem. No patients with a positive ESBL-E phenotype had a history of hospital admission in the last three months, and the carriage of ESBL-E was neither associated with the demographic nor the clinical characteristics of participants. Our findings reveal a low presence of ESBL-E phenotypes in community patients. The low prevalence of ESBL-E in the community settings of Blantyre can be maintained if strong infection and antimicrobial use-control strategies are implemented.

Detection of NDM-1 and VIM Genes in Carbapenem-Resistant Klebsiella pneumoniae Isolates from a Tertiary Health-Care Center in Kathmandu, Nepal

BACKGROUND

Klebsiella pneumoniae is one of the leading causes of nosocomial infections. Carbapenems are used as the last resort for the treatment of multidrug resistant Gram-negative bacterial infections. In recent years, resistance to these lifesaving drugs has been increasingly reported due to the production of carbapenemase. The main objective of this study was to detect the carbapenem-resistant genes blaNDM-1 and blaVIM in K. pneumoniae isolated from different clinical specimens.

METHODS

A total of 585 clinical specimens (urine, pus, sputum, blood, catheter tips, and others) from human subjects attended at Annapurna Neurological Institute and Allied Sciences, Kathmandu were obtained in the period between July 2018 and January 2019. The specimens were isolated and identified for K. pneumoniae. All K. pneumoniae isolates were processed for antimicrobial susceptibility testing (AST) using the disk diffusion method. The isolates were further phenotypically confirmed for carbapenemase production by the modified Hodge test (MHT) using imipenem (10 μg) and meropenem (10 μg) discs. Thus, confirmed carbapenemase-producing isolates were further screened for the production of blaNDM-1 and blaVIM using conventional polymerase chain reaction (PCR).

RESULTS

Among the clinical isolates tested, culture positivity was 38.29% (224/585), and the prevalence of K. pneumoniae was 25.89% (58/224). On AST, K. pneumoniae exhibited resistance toward carbapenems including ertapenem, meropenem, and imipenem, while it showed the highest susceptibility rate against to tigecycline (93.1%; 54/58). Overall, AST detected 60.34% (35/58) carbapenem-resistant isolates, while the MHT phenotypically confirmed 51.72% (30/58) isolates as carbapenemase-producers and 48.28% (28/58) as carbapenemase nonproducers. On subsequent screening for resistant genes among carbapenemase-producers by PCR assay, 80% (24/30) and 3.33% (1/30) isolates were found to be positive for blaNDM-1 and blaVIM, respectively. In the same assay among 28 carbapenem nonproducing isolates, 9 (32.14%) isolates were positive for blaNDM-1 gene while none of them were tested positive for blaVIM gene.

CONCLUSIONS

Molecular detection of resistant genes provides greater specificity and sensitivity than those with conventional techniques, thus aiding in accurate identification of antimicrobial resistance and clinical management of the disease.

Characterisation of ESKAPE Pathogens with Special Reference to Multidrug Resistance and Biofilm Production in a Nepalese Hospital

Background

“ESKAPE” is an acronym for a group of life-threatening nosocomial pathogens, viz, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp. Global efforts on controlling multidrug-resistant (MDR) organisms have been hampered by their ability to escape antibacterial drugs. This study was undertaken to determine the prevalence of ESKAPE pathogens with prime focus on biofilm production and antibiotic resistance.

Methods

A total of 8756 clinical samples were processed for the isolation and identification of ESKAPE pathogens following standard microbiological procedures. These isolates were subjected to antimicrobial sensitivity test as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Test for MDR, extended-spectrum β-lactamase (ESBL), metallo-β-lactamase (MBL), methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE) was done by the disk diffusion and E-test methods. In the case of VRE molecular detection was done for vanA and vanB genes. All the isolates were processed for biofilm detection by the tube adherence method.

Results

The percentage distribution of Enterococcus faecium was 5.5%, S. aureus 33.4%, K. pneumoniae 33.0%, A. baumannii 8.6%, P. aeruginosa 18.6%, and Enterobacter aerogenes 0.9%. MRSA was 57.6%, and vancomycin resistance among Enterococcus faecium was 20%. ESBL- and MBL-producing K. pneumoniae were 16.1%, and 8.1%, A. baumannii 10.3% each and P. aeruginosa 10.7% and 8.3%, respectively. A total of 42.3% of isolates were biofilm producers. Linezolid was the drug of choice for VRE. Ampicillin-sulbactam was most useful against A. baumannii apart from polymyxins, whereas piperacillin-tazobactam was effective against other Gram-negative bacteria. VanA gene was detected in all the VRE isolates.

Conclusion

This study estimates the burden of the ESKAPE organisms and their antimicrobial resistance pattern in a hospital setting. A high percentage of drug resistance and biofilm production was noted; hence antimicrobial resistance surveillance targeting ESKAPE pathogens should be incorporated in the infection control policy in Nepal.

Prevalence of CTX-M β-Lactamases Producing Multidrug Resistant Escherichia coli and Klebsiella pneumoniae among Patients Attending Bir Hospital, Nepal

The emergence of multidrug resistant (MDR) bacteria which is attributable to extended spectrum β-lactamases (ESBLs) production of CTX-M types is an obvious problem worldwide. This study is aimed at determining the prevalence of CTX-M β-lactamases producing multidrug resistant Escherichia coli and Klebsiella pneumoniae among patients attending Bir Hospital. A cross-sectional study was conducted between April and September 2019 at Bir Hospital, Kathmandu, and Department of Microbiology, National College, Kathmandu, Nepal. A total of 5,690 different clinical specimens were subjected to cultural, microscopic, and biochemical analyses for the identification of the isolates. Antimicrobial susceptibility testing of the isolates was done, and MDR isolates were selected and processed for further ESBL confirmation by the combination disks method. All confirmed ESBL isolates were screened for CTX-M type β-lactamases (bla _CTX-M) by PCR. Of the total 345 isolates (227 Escherichia coli and 118 Klebsiella pneumoniae), 232 were MDR. All 232 (67.24%) MDR isolates were suspected as ESBL producers on the screening test. However, on the phenotypic test, 135 (58.18%) of total MDR bacteria were confirmed as ESBL producers with the highest proportion in K. pneumoniae (59.37%). The major source of ESBL producers was urine. ESBL producing isolates were mostly identified from outpatients and patients belonging to age group 41-60. Gentamicin was found to be effective against ESBL producers. The prevalence of bla _CTX-M was (89.62%) with the highest frequency for E. coli (93.81%). High prevalence of ESBL of CTX-M types among MDR E. coli and K. pneumoniae was detected from clinical specimens of patients in Bir Hospital. This study warrants the need for the judicious use of antibiotics as well as emphasize the use of modern diagnostic tools for the early detection of MDR and ESBL producers to curb the emergence and spread of MDR and ESBL producing bacteria in the clinical settings of Nepal.

A Study on Prevalence of Extended Spectrum Beta-lactamases Gene (CTX-M, TEM & SHV) Producing Enterobacteriaceae Members Isolated from Different Clinical Specimens at Tertiary Care Hospital, Uttarakhand

Extended spectrum b-lactamases (ESBLs) are one of the major enzymes responsible for antimicrobial drug resistance in bacterial isolates. The objective of this study was to find out the ESBL genes (blaTEM, blaSHV and blaCTX-M) in Enterobacteriaceae. This study was conducted from November 2013 to October 2015. The identification of Enterobacteriaceae isolates & antimicrobial drug resistance was done by conventional standard microbial methods. Further genotypic detection of ESBL was done by multiplex PCR. Results: Among 942 Enterobacteriaceae isolates, 332 (35.24%) isolates was ESBL producers. We observed high prevalence of ESBL enzyme in Klebsiella pneumonia (59.09%). These isolate revealed high resistance to co-trimoxazole, fluoroquinolones and aminoglycosides. Out of 48 randomly selected isolates, ESBL genes were identified in 45 isolates which were found resistant to third generation cephalosporins. Single CTX-M gene noticed in 29 strains of Escherichia coli (E. coli), 02 strains of Klebsiella pneumoniae, and 01 strain of Proteus mirabilis. Occurrence of Combination of the genes e.g., (blaTEM+blaCTX-M), (blaSHV+blaCTX-M), (blaTEM+blaSHV+blaCTX-M) was detected in 08, 01 and 04 isolates respectively. Multiplex PCR in CTX-M carrying isolates revealed the presence of blaCTX-M group-1. The most common blaCTX-M group-1 was observed in all isolates of family Enterobacteriaceae. Antimicrobial drug resistance is a major problem of concern now a day. Studies like this will be helpful to knowing the burden of multi drug resistance as well as formulating antibiotics policy for a particular region.

Extended-spectrum Beta-lactamase and AmpC beta-lactamases producing gram negative bacilli isolated from clinical specimens at International Clinical Laboratories, Addis Ababa, Ethiopia

BACKGROUND

Extended spectrum Beta-lactamases (ESBLs) and AmpC beta-lactamases (AmpC) are the common enzymes produced by gram negative bacilli, which are their main mechanisms of resistance to all generations of cephalosporins. Hence, this study aimed to determine the magnitude of ESBLs and AmpC producing gram negative bacilli (GNB) isolated from clinical specimens at International clinical Laboratories in Addis Ababa, Ethiopia.

METHODS

A cross sectional study was conducted from January to May 2018. From different clinical specimens, 338 GNB were isolated and characterized. Bacterial species identification, antimicrobial susceptibility testing and screening for ESBLs and AmpC production were performed using Phoenix automated system (BD phoenix100). ESBLs production was confirmed using a combination disc method. All Cefoxitin resistant and confirmed ESBLs producing GNB were confirmed for AmpC beta-lactamases production by AmpC confirmatory Neo-Sensitabs discs (ROSCO tablet). Data were analyzed using SPSS version 20 software.

RESULTS

E. coli 66.0% (224/338) followed by K. pneumoniae 12.1% (41/338) were GNB most frequently isolated. The overall magnitude of ESBLs producing GNB was 38.8% (131/338) and the extent of AmpC beta-lactamase producing GNB was 2.4% (8/338). Majority of ESBLs and AmpC beta-lactamases producing GNB were isolated from urine specimens 47.5% (116/338). Ampicillin (75.4%), amoxicillin with clavulanic acid (64.0%) and sulfamethoxazole-trimethoprim (55.6%) were most the antibiotics to which resistance was most commonly found. The multidrug resistance (MDR) level of GNB was 74.0% (250/338). Of ESBLs and AmpC beta-lactamases producing GNB, 99.3% were MDR (p < 0.05).

CONCLUSION

The high magnitude of ESBLs and AmpC beta-lactamases producing GNB calls the needs of strong intervention to minimize further occurrence and spread of such GNB. More importantly, the MDR level was high which suggests continuous monitoring & reviewing of antimicrobial policy in hospitals and the country at large.

Determination of the frequency of β-lactamase genes (bla SHV, bla TEM, bla CTX-M) and phylogenetic groups among ESBL-producing uropathogenic Escherichia coli isolated from outpatients

Background

Escherichia coli accounts for 70–95% of community-acquired urinary tract infections (UTIs). Recently, there has been an increase in the prevalence of extended-spectrum β-lactamase (ESBL) in the community which required an accurate identification for better management. Therefore, the current study was performed to determine the antimicrobial resistance pattern, investigate ESBL phenotypes and genotypes (blaCTX-M, bla TEM and bla SHV genes) and determine the phylogenetic groups among ESBL-positive isolates from outpatients.

Methods

One hundred and eighty-three positive urine samples were collected from 4450 outpatient clinic attendees. Antibiotic susceptibility was determined and ESBL phenotype screening was carried out using disk diffusion agar and combination disk techniques, respectively. The assessment of the presence of the blaCTX-M, bla TEM and blaSHV genes and phylogenetic grouping were performed using the polymerase chain reaction (PCR) method.

Results

Out of 183 E. coli isolates, 59 (32.2%) showed a positive ESBL phenotype. The prevalence of ESBL-producing E. coli was higher in males (57.4%). Fifty-seven of the ESBL-producing strains carried at least one of the β-lactamase genes (bla CTX-M, bla TEM, bla SHV). Phylotyping of multi-drug resistant isolates indicated that the isolates belonged to B2, A and D phylogroups. Analysis of resistance patterns among these phylogroups revealed that 74.4%, 55.3% and 29.7% of the isolates in the B2 group were resistant to trimethoprim-sulfamethoxazole, ciprofloxacin and gentamicin, respectively. Most of the strains in the phylogroup B2 carried the bla CTX-M gene.

Conclusions

All the ESBL-producing isolates were placed in one of the four phylogenetic groups. The presence of CTX-M and resistance to quinolones were more frequent in B2 strains than in non-B2 strains.

Multidrug-resistant profile and prevalence of extended spectrum β-lactamase and carbapenemase production in fermentative Gram-negative bacilli recovered from patients and specimens referred to National Reference Laboratory, Addis Ababa, Ethiopia

Background

The emergence of multidrug-resistance (MDR), production of extended-spectrum β-lactamases, and carbapenemase in members of fermentative gram-negative bacilli are a serious threat to public health.

Objective

The aim of this study was to determine the burden of multi-drug resistance, the production of extended-spectrum β-lactamases (ESBLs), and carbapenemase in fermentative Gram-negative bacilli in Ethiopian Public Health Institute.

Materials and methods

A cross-sectional study was carried out from December 2017 to June 2018. Different clinical samples were collected, inoculated, and incubated according to standard protocols related to each sample. Bacterial identification was performed by using the VITEK^R 2 compact system using the GN^R card. Antimicrobial susceptibility testing was carried out by the Kirby-Bauer disc diffusion method. Production of ESBL and carbapenemase were confirmed by combination disc and modified Hodge Test method respectively.

Results

A total of 238 fermentative Gram-negative bacilli were recovered during the study period, among which E.coli were the predominant isolates followed by K. pneumoniae. The highest percentage of antibiotic resistance was noted against ampicillin (100%) followed by trimethoprim/sulfamethoxazole (81.9%). The isolates showed better sensitivity towards carbapenem drugs. Out of 238 isolates, 94.5% were MDR and of which 8.8% and 0.8% were extensively and pan drug resistant, respectively. Nearly 67% and 2% of isolates were producers of ESBL and carbapenemase, respectively. The isolation rates of MDR, ESBL, and carbapenemase producing stains of the isolates were ≥70% in intensive care unit while the isolation rates in other wards were ≤25%.

Conclusions

The findings of this study revealed that the burden of MDR and ESBL was high and carbapenemase producing isolates were also identified which is concerning. This situation warrants a consistent surveillance of antimicrobial resistance of fermentative Gram-negative bacilli and implementation of an efficient infection control program.

Detection of VIM-1, VIM-2 and IMP-1 metallo- β-lactamase genes in Klebsiella pneumoniae isolated from clinical samples in Sanandaj, Kurdistan, west of Iran

BACKGROUND AND OBJECTIVES

Klebsiella pneumoniae is an important cause of serious nosocomial infections among Gram-negative bacteria. The aim of this study was evaluating the prevalence of VIM-1, VIM-2, and IMP-1 metallo-β-lactamase genes in clinical specimens at two teaching hospitals in Sanandaj, Kurdistan west of Iran.

MATERIALS AND METHODS

Four hundred different clinical specimens were collected from hospitalized patients or referred to hospitals from May 2013 to March 2014 in Sanandaj, Kurdistan, Iran. MBLs - producing K. pneumoniae detected by Double Disk Synergy Test. The MBL positive isolates were examined for the presence of VIM-1, VIM-2 and IMP-1 genes using PCR technique.

RESULTS

Of four hundred clinical specimens, 114 K. pneumoniae isolates were identified. Twenty-eight (24.6%) isolates were resistant to imipenem and 15 strains (53.6%) were positive for MBL enzymes production. PCR results showed VIM-1 and IMP-1 genes frequencies are 4 (26.7%) and 1 (6.7%). Only one strain of K. pneumoniae was found to be MBL producer among the outpatients.

CONCLUSION

The study results exhibited a high level of resistance to most of the antibiotics tested and high prevalence of MBLs producing in K. pneumoniae at two hospitals. Thus, the infection control methods and the implementation of antibiotic agents should be taken into account.

Extended-spectrum beta-lactamase production and multi-drug resistance among Enterobacteriaceae isolated in Addis Ababa, Ethiopia

Background

The global emergence and spread of extended-spectrum beta-lactamases (ESBLs) producing Enterobacteriaceae have been threatening the ability to treat an infection. Hence, this study aimed to determine the prevalence of ESBL-producing and multi-drug resistance (MDR) Enterobacteriaceae (ESBLs-E) from different clinical specimens in Addis Ababa, Ethiopia.

Methods

A cross-sectional study was conducted from January 1 to May 30, 2017. A total of 426 Enterobacteriaceae isolates were identified from clinical specimens. The isolates were collected from four laboratories. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method on Muller Hinton agar (MHA). All Enterobacteriaceae were screened for ESBLs production using cefotaxime and ceftazidime as per CLSI guideline. Each ESBL screening positive Enterobacteriaceae were confirmed by a combination disk test (CDT). Data were entered and analyzed by using SPSS version-20.

Result

The most frequent Enterobacteriaceae were E. coli 228 (53.5%) and K. pneumoniae 103 (24.1%). The magnitude of ESBLs-E was 57.7% (246/426). The highest frequencies of ESBLs-E were observed in blood specimesns (84.4%) and the highest ESBLs production was observed in K. pneumoniae (85.4%). The highest resistance level was seen to sulfamethoxazole-trimethoprim (77.0%), amoxicillin with clavulanic acid (71.6%), cefotaxime (62.2%), cefepime (60.3%) and ceftazidime (60.8%). The overall magnitude of multi-drug resistance (MDR) level was 68.3%. Of ESBLs-E, 96.3% of them were MDR (P < 0.001).

Conclusion

There was a high prevalence of ESBLs-E and MDR isolate in Addis Ababa. Most of ESBLs-E was isolated primarily in blood and urine. The highest ESBLs production was observed among K. pneumoniae. Hence, strong infection control strategies must be implemented in hospital settings of the country.

Extended spectrum beta-lactamase and metallo beta-lactamase production among Escherichia coli and Klebsiella pneumoniae isolated from different clinical samples in a tertiary care hospital in Kathmandu, Nepal

Background

Extended spectrum beta-lactamase (ESBL) and metallo beta-lactamase (MBL) production in Klebsiella pneumoniae and Escherichia coli are the commonest modes of drug resistance among these commonly isolated bacteria from clinical specimens. So the main purpose of our study was to determine the burden of ESBL and MBL production in E. coli and K. pneumoniae isolated from clinical samples. Further, the antimicrobial susceptibility patterns of E. coli and K. pneumoniae were also determined.

Methods

A cross-sectional study was conducted at Om Hospital and Research Centre, Kathmandu, Nepal by using the E. coli and K. pneumoniae isolated from different clinical samples (urine, pus, body fluids, sputum, blood) from May 2015 to December 2015. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique. Extended spectrum beta-lactamase production was detected by combined disc method using ceftazidime and ceftazidime/clavulanic acid discs and cefotaxime and cefotaxime/clavulanic acid discs. Similarly, metallo beta-lactamase production was detected by combined disc assay using imipenem and imipenem/ethylenediaminetetracetate discs. Bacteria showing resistance to at least three different classes of antibiotics were considered multidrug resistant (MDR).

Results

Of total 1568 different clinical samples processed, 268 (17.1%) samples were culture positive. Among which, E. coli and K. pneumoniae were isolated from 138 (51.5%) and 39 (14.6%) samples respectively. Of the total isolates 61 (34.5%) were ESBL producers and 7 (4%) isolates were found to be MBL producers. High rates of ESBL production (35.9%) was noted among the clinical isolates from outpatients, however no MBL producing strains were isolated from outpatients. Among 138 E. coli and 39 K. pneumoniae, 73 (52.9%) E. coli and 23 (59%) K. pneumoniae were multidrug resistant. The lowest rates of resistance was seen toward imipenem followed by piperacillin/tazobactam, amikacin and cefoperazone/sulbactam.

Conclusions

High rate of ESBL production was found in the E. coli and K. pneumoniae isolated from outpatients suggesting the dissemination of ESBL producing isolates in community. This is very serious issue and can’t be neglected. Regular monitoring of rates of ESBL and MBL production along with multidrug resistance among clinical isolates is very necessary.

Types and prevalence of extended-spectrum beta-lactamase producing Enterobacteriaceae in poultry

For several billion years, bacteria have developed mechanisms to resist antibacterial substances. In modern time, antibiotics are frequently used in veterinary and human medicine for prevention and treatment of diseases, globally still also for their growth promoting effects as feed additives. This complex situation has evolved in accelerating development and prevalence of multi-drug resistant bacteria in livestock and people. Extended-spectrum beta-lactamase (ESBL) producing bacteria are resistant to a wide range of ß-lactam antibiotics. They are currently considered as one of the main threats for the treatment of infections in humans and animals. In livestock and animal products, poultry and poultry products show the highest prevalence of ESBL-producers with CTX-M-1, TEM-52 and SHV-12 being the most common ESBL-types in poultry. Escherichia coli and Salmonella spp. are the bacteria in poultry, which carry ESBL-genes most frequently. ESBL-producing bacteria are present at every level of the poultry production pyramid and can be detected even in the meconium of newly hatched chicks. The environment close to poultry barns shows high prevalence rates of these bacteria and contributes to an ongoing infection pressure with further ESBL-types. Probiotics have been shown to successfully reduce ESBL-producers in chicken, as well as ESBL-gene transfer. Other feed additives, such as zinc and copper, increase the prevalence of ESBL-producing bacteria when fed to animals. To our best knowledge, this is the first publication presenting a comparative overview of the prevalence of ESBL-types using data from different countries. To reduce the hazard for public health from poultry carrying high numbers of ESBL-producers, preventive measurements must include the surrounding environment and avoidance of antibiotic usage at all levels of the production pyramid. The first results, of the research on the impact of feed additives on the spread of ESBL-genes, indicate the diet as a further, possible magnitude of influence.

Bacteriological profile and antibiotic susceptibility patterns of clinical isolates in a tertiary care cancer center

Introduction:

This increased risk of bacterial infections in the cancer patient is further compounded by the rising trends of antibiotic resistance in commonly implicated organisms. In the Indian setting this is particularly true in case of Gram negative bacilli such as Escherichia coli, Klebsiella pneumoniae and Acinetobacter spp. Increasing resistance among Gram positive organisms is also a matter of concern. The aim of this study was to document the common organisms isolated from bacterial infections in cancer patients and describe their antibiotic susceptibilities.

Methods:

We conducted a 6 month study of all isolates from blood, urine, skin/soft tissue and respiratory samples of patients received from medical and surgical oncology units in our hospital. All samples were processed as per standard microbiology laboratory operating procedures. Isolates were identified to species level and susceptibility tests were performed as per Clinical Laboratory Standards Institute (CLSI) guidelines -2012.

Results:

A total of 285 specimens from medical oncology (114) and surgical oncology services (171) were cultured. Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Acinetobacter spp. were most commonly encountered. More than half of the Acinetobacter strains were resistant to carbapenems. Resistance in Klebsiella pneumoniae to cephalosporins, fluoroquinolones and carbapenems was >50%. Of the Staphylococcus aureus isolates 41.67% were methicillin resistant.

Conclusion:

There is, in general, a high level of antibiotic resistance among gram negative bacilli, particularly E. coli, Klebsiella pneumoniae and Acinetobacter spp. Resistance among Gram positives is not as acute, although the MRSA incidence is increasing.