Biofilm formation and antimicrobial resistance in Klebsiella pneumoniae isolated from patients visiting a tertiary care center of Nepal

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.

Systematic Review and Meta-analysis on Extended-Spectrum β-lactamases Producing Klebsiella pneumoniae in Nepal

Objective

This systematic review and meta-analysis aimed to assess the pool estimates of extended-spectrum β-lactamases producing K. pneumoniae (ESBL-KP) and study their drug resistance profile by evaluating the studies from Nepal.

Methods

A literature search was carried out in PubMed, Google Scholar, and NepJOL to screen all articles on ESBL-KP published between 2011 and 2021 from Nepal. This review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Relevant data were extracted, and R language 4.2.0 software was used for statistical analysis.

Results

The pooled prevalence of K. pneumoniae was 5%, while the pooled prevalence of ESBL and multidrug resistance (MDR) in K. pneumoniae were 23% and 55%, respectively. Imipenem was the drug of choice (in vitro) against ESBL-KP infection.

Conclusion

Our analyses showed a high prevalence of ESBL-KP and their high resistance toward commonly used drugs. This study highlights the need for the development of new antibiotics for the management of ESBL-KP infections.

Evaluation of the biotechnological potential of peptide Cupiennin 1a and analogs

Antimicrobial peptides (AMPs) are components in the innate immune system of various organisms, and many AMPs can be found in poisons from animals such as spiders, scorpions, and snakes. The peptide Cupiennin-1a is present in the venom of the spider Cupiennius salei and belongs to a group of peptides called cupiennins. The peptide demonstrated high cytotoxic activity against mammalian cells; thus, aiming to solve this problem, seven analogs were designed (R1a, R1b, R2b, R3b, R6b, R8b, and R10b) based on the primary structure of the peptide Cupiennin 1a, reducing its size and substituting some amino acid residues. The antimicrobial results showed that all Cupiennin 1a analogs displayed antimicrobial activity against the tested bacterial and fungal strains. Cytotoxicity tests demonstrated a decrease in the cytotoxic effect of the analogs when compared to the peptide Cupiennin-1a. The antitumor activity against breast adenocarcinoma lines was observed for all the peptides, displaying a better effect against the MCF-7 and MDAMB-231 cell lines. The eight peptides have insecticidal potential, and the original peptide and analogs R6b, R8b, and R10b showed better efficiency even at low concentrations. The rational design of the analogs led to new molecules displaying activities against different cell types and reduced cytotoxicity toward healthy mammalian cells when compared to the original peptide, demonstrating that this was an interesting approach for the development of molecules with biotechnological potential.

CTX-M-producing Escherichia coli strains: resistance to temocillin, fosfomycin, nitrofurantoin and biofilm formation

Aim: ESBL-producing and bacterial biofilms-forming Escherichia coli are associated with antimicrobial treatment failure. This study aimed to investigate the phenotypic resistance mechanisms of CTX-M E. coli against old antibiotics - cell wall synthesis inhibitors temocillin, nitrofurantoin and fosfomycin. Materials & Methods: Susceptibility to old antibiotics testing was performed using disk diffusion method, biofilm formation was evaluated spectrophotometrically, and PCR was used for the determination of CTX-M type. Results & conclusion: Temocillin was active against nearly 93%, nitrofurantoin and fosfomycin, respectively, 91.7% and 98.6% of tested E. coli. Thus, it demonstrated to be a good alternative therapeutic option against ESBL infections. Bacteria resistant to old antibiotics had CTX-M-15 or CTX-M-15, TEM-1 and OXA-1 combinations. No significant association was found between CTX-M E. coli resistance to temocillin, nitrofurantoin and fosfomycin; however, the level of biofilm formation was found as not affected by the type of CTX-M β-lactamases.

Biofilm Formation and Phenotypic Detection of ESBL, MBL, KPC and AmpC Enzymes and Their Coexistence in Klebsiella spp. Isolated at the National Reference Laboratory, Kathmandu, Nepal

Klebsiella spp. are associated with several nosocomial and opportunistic infections. Increasing antimicrobial resistance of Klebsiella species is aggravated by a number of intrinsic and extrinsic factors. The main aim of this study is to determine antimicrobial resistance due to production of β-lactamase enzymes, extended spectrum beta-lactamase (ESBL), metallo-beta-lactamase (MBL) and AmpC and Klebsiella pneumoniae carbapenemase (KPC) and biofilm formation in Klebsiella isolates. A total of 2197 non-duplicate specimens of urine, sputum and pus were obtained from the National Public Health Laboratory (NPHL), Kathmandu, Nepal, between February and August 2019. Klebsiella species were isolated, identified and screened for antimicrobial susceptibility testing with the disk diffusion method. Phenotypic detection of ESBL, MBL, KPC and AmpC production was observed and biofilm production was detected by the microtiter plate method. Out of a total of 2197 clinical specimens, bacterial growth was detected in 8% (175/2197) of the specimens. Of the total isolates, 86.3% (151/175) were Gram-negative bacteria and 37.7% (57/151) were Klebsiella spp. Of the total Klebsiella spp., 56% (32/57) were multi drug resistant (MDR), 16% (9/57) were ESBL, 26% (15/57) were MBL, 4% (2/57) were KPC (class A carbapenemase), 16% (9/57) were AmpC producers and 95% (54/57) were biofilm producers. Gentamicin was the most effective antibiotic, followed by cotrimoxazole, as 68% (39/57) and 47% (27/57) of the Klebsiella isolates were susceptible towards these drugs, respectively. The study results show evidence of β-lactamase production, high prevalence of MDR and biofilm producing Klebsiella species. Integrating the test parameters for phenotypic confirmation of ESBL, MBL, AmpC β lactamase and KPC in routine diagnostic procedures can help in the early detection and management of these resistant strains.

Biofilm Formation by Pathogens Causing Ventilator-Associated Pneumonia at Intensive Care Units in a Tertiary Care Hospital: An Armor for Refuge

Background

Emerging threat of drug resistance among pathogens causing ventilator-associated pneumonia (VAP) has resulted in higher hospital costs, longer hospital stays, and increased hospital mortality. Biofilms in the endotracheal tube of ventilated patients act as protective shield from host immunity. They induce chronic and recurrent infections that defy common antibiotics. This study intended to determine the biofilm produced by pathogens causing VAP and their relation with drug resistance.

Methods

Bronchoalveolar lavage and deep tracheal aspirates (n = 70) were obtained from the patients mechanically ventilated for more than 48 hours in the intensive care units of Tribhuvan University Teaching Hospital, Kathmandu, and processed according to the protocol of the American Society for Microbiology (ASM). Antibiotic susceptibility testing was done following Clinical and Laboratory Standards Institute (CLSI) 2017 guidelines. Biofilm formation was determined using the microtiter plate method described by Christensen and modified by Stepanovoic et al.

Results

Significant microbial growth was seen in 78.6% of the total samples with 52.7% monomicrobial, 45.5% polymicrobial, and 1.8% fungal infection. Among the 71 isolates obtained, bulk was gram-negative (n = 64, 90.1%). Pseudomonas aeruginosa (31.0%) was the predominant isolate followed by Acinetobacter calcoaceticus baumannii complex (16.9%), Klebsiella pneumoniae (16.9%), Citrobacter freundii (15.5%), Staphylococcus aureus (7.0%), Escherichia coli (5.6%), Citrobacter koseri (2.8%), Enterococcus faecalis (1.4%), Burkholderia cepacia complex (1.4%), and Candida albicans (1.4%). Of the total isolates, 56.3% were biofilm producers. Multidrug-resistant (MDR) organisms, extended-spectrum β-lactamase (ESBL), and metallo-β-lactamase (MBL) producers were preeminent among the biofilm producers. The highest producer of biofilm was P. aeruginosa (19.7%). Among gram-negative biofilm producers, 42.2% were MDR, 21.9% were ESBL producers, and 7.8% were MBL producers.

Conclusion

Gram-negative nonfermenter bacteria account for the bulk of nosocomial pneumonia. MDR, ESBL, and MBL production was preponderant among the biofilm producers. The rampant spread of drug resistance among biofilm producers is summoning novel interventions to combat multidrug resistance.

Study of Various Virulence Genes, Biofilm Formation and Extended-Spectrum β-lactamase Resistance in Klebsiella pneumoniae Isolated from Urinary Tract Infections

Objective:

The aims of the current study were to evaluate the capacity of K. pneumoniae isolated from hospital-acquired urinary tract infection to form biofilm, the relation of this capacity to various virulence genes and the prevalence of Extended Spectrum β-lactamases (ESBL) among these isolates by phenotypic and genotypic methods.

Material and Methods:

The study included 100 non-duplicate strains of K. pneumoniae isolated from 100 different urine samples from patients with hospital-acquired urinary tract infection. The isolated strains were studied for biofilm formation, ESBL production by phenotypic methods. Molecular studies were applied for the detection of ESβLs genes blaTEM, blaSHV, blaCTX-M and for detection of virulence genes fimH, uge, rmpA, mag A, wzy, kfa and aerobactin genes.

Result:

The majority of the isolates had the capacity to form a biofilm (81%), with ESBL prevalence rate 41%. The most prevalent gene among ESBL producing K. pneumoniae was blaCTX-M (73.2%) followed by blaSHV (53.6%) and blaTEM (51.2%). Among the virulence genes studied in K. pneumoniae isolates, the most prevalent gene was fimH (76%), uge (70%). There was significant association between ESBL production, and resistance to amikacin, cefepime, ceftazidime, gentamicin, imipenem and meropenem and biofilm production in K. pneumoniae isolates. There was significant association between blaCTX-M, blaSHV, fimH, mag, kfa, wzy, rmpA and aerobactin and biofilm production in K. pneumoniae.

Conclusion:

The present study highlights the prevalence of virulence genes among biofilm-forming strains of K. pneumoniae isolated from hospital-acquired urinary tract infection. Moreover, there was association between biofilm formation and ESBL production. Further studies are required to elucidate the clinical impact of the association of these different mechanisms.