Prevalence of colistin resistance of Klebsiella pneumoniae isolates in Iran: a systematic review and meta-analysis

Prevalence, trends, and molecular insights into colistin resistance among gram-negative bacteria in Egypt: a systematic review and meta-analysis

BACKGROUND

This study examines colistin resistance in Gram-negative bacteria in Egypt, analyzing prevalence, trends, geographic variations, colistin-carbapenem resistance correlation, and mcr-mediated plasmid resistance.

METHODS

We conducted a systematic search of articles published between 2014 and 2024 that reported on colistin or mcr-mediated resistance in Gram-negative bacteria isolated from human infections in Egypt, with clearly defined susceptibility testing methods. A random-effects meta-analysis was conducted to estimate colistin resistance prevalence based on broth microdilution (BMD) findings, the gold standard method. To explore the influence of study-level factors-including alternative susceptibility testing methods-a multivariate meta-regression analysis was performed. The results of the meta-regression are reported as regression coefficients (β), representing the difference in colistin resistance, expressed in percentage points. All statistical analyses were conducted using R software.

RESULTS

This analysis included 55 studies. Based on BMD susceptibility testing, colistin resistance was observed in 9% of all recovered Gram-negative isolates (95% CI: 6-14%) and was significantly higher among carbapenem-resistant isolates (31%, 95% CI: 25-38%), with p < 0.001. Multivariate meta-regression analysis further confirmed that colistin resistance was significantly higher in carbapenem-resistant isolates compared to the total recovered isolates (β = 9.8% points, p = 0.001). Additionally, colistin resistance has significantly increased over time, with a β = 1.8% points per year (p = 0.001). The use of the VITEK 2 system was associated with lower detected colistin resistance compared to BMD (β = -7.0, p = 0.02). Geographically, resistance rates were higher in Upper Egypt (β = 9.3, p = 0.04). Regarding mcr plasmid-mediated resistance, mcr-1 was the most prevalent resistance gene, particularly in E. coli. In contrast, mcr-2 was rare, detected sporadically in K. pneumoniae and P. aeruginosa.

CONCLUSION

In Egypt, BMD testing identified colistin resistance in 9% of Gram-negative bacteria, increasing to 31% in carbapenem-resistant isolates. This higher resistance in carbapenem-resistant strains suggests stronger selective pressure from frequent colistin use. Additionally, colistin resistance has shown a rising trend over time, likely driven by increased usage and the spread of plasmid-mediated resistance. These findings underscore the urgent need for strict antimicrobial stewardship and alternative therapies to curb resistance evolution.

Effects of in vitro combination therapy with polymyxin B on delaying resistance in Klebsiella pneumoniae and insights into the mechanisms of polymyxin-induced resistance

OBJECTIVE

This study aimed to investigate the effects of polymyxin B (PMB) in combination with other antibiotics on delaying resistance in Klebsiella pneumoniae and to explore the mechanisms underlying PMB-induced resistance.

METHODS

In vitro continuous induction experiments were performed to observe changes in drug susceptibility with PMB alone vs. in combination. RNA-seq, quantitative reverse transcription PCR, and proteomic analyses were utilized to evaluate differential gene and protein expression between induced-resistant strains and those exhibiting delayed resistance. Then, gene knockout experiments were performed to validate the functional roles of relevant genes.

RESULTS

These findings indicated that PMB alone could induce resistance within 1-2 d, whereas the combination with amikacin (AMK) or tigecycline delayed the onset of resistance by 6 d. RNA-seq, quantitative reverse transcription PCR, and proteomic analyses revealed significant upregulation of nlpE, two-component systems, and AcrAB-TolC efflux pump-associated genes in PMB-induced resistant strains, whereas these genes were downregulated in the delayed resistant strains of PMB combined with AMK. Deletion and complementation experiments demonstrated that the expression levels of two-component systems and efflux pump-related genes were downregulated in nlpE knockout strains. Furthermore, PMB induction experiments revealed a significant upregulation of PmrA, PhoP, PhoQ, PagP, and AcrB proteins associated with cationic antimicrobial peptide pathways in the wild-type and nlpE complemented strains, whereas no differential change was observed in the nlpE knockout strain.

CONCLUSIONS

nlpE contributes to PMB resistance by modulating the AcrAB-TolC efflux pump and the PhoP/Q and PmrA/B two-component systems. The combined use of PMB with AMK effectively delays the development of resistance in K. pneumoniae through the regulation of nlpE and its associated signalling pathways.

Prevalence of Colistin-Resistant Klebsiella pneumoniae Isolates in Turkey over a 20-Year Period: A Systematic Review and Meta-Analysis

Klebsiella pneumoniae is one of the leading causes of healthcare-associated infections and poses challenges in its treatment owing to its high antibiotic resistance. The development of resistance to colistin, which is used as a last resort, has become a major public health problem worldwide. This study was planned according to the PRISMA guidelines and included studies reporting the prevalence of colistin-resistant K. pneumoniae in Turkey between 2004 and 2024 through a systematic literature review. A total of 28 original research articles were included in the meta-analysis. Data were analyzed using the SPSS and CMA software. The pooled colistin resistance of a total of 8916 K. pneumoniae strains from 28 studies included in this meta-analysis was found to be 1.63% (95% CI: 1.51-3.12). Colistin resistance increased significantly over time. A higher resistance rate was detected in the strains tested using the EUCAST guidelines and broth microdilution method. The year of the study and validation methods contributed to the heterogeneity observed in the studies. This meta-analysis reveals that colistin-resistant K. pneumoniae strains have increased over time in Turkey. Current data show that colistin resistance is not only a laboratory finding but has become a crisis, requiring urgent action in terms of hospital infection management and patient safety. Regional and global measures should be taken to ensure the appropriate use of antibiotics to control the development of resistance.

Investigation of Colistin resistance and method comparison in Klebsiella pneumoniae strains

PURPOSE

This study aimed to assess the prevalence of colistin resistance in the study group and compare alternative methods with the gold standard. It sought to evaluate the prevalence of plasmid-mediated colistin resistance genes.

MATERIAL AND METHODS

The colistin susceptibility of 151 K. pneumoniae strains was determined using Sensititre™, CBDE, ETEST®, and VITEK®2. Results were compared with BMD. The presence of the mcr gene was assessed using polymerase chain reaction.

RESULTS

The colistin resistance rate was 16,6 %. The categorical agreement of Sensititre™, CBDE, and ETEST® was 100 %. VITEK®2 had a CA of 98 %, a major error of 0.79 %, and a very major error of 8 %. Essential agreement for Sensititre™, ETEST®, and VITEK®2 was 92.7 %, 52.3 %, and 78.1 %, respectively. There were no mcr genes in any strains.

CONCLUSIONS

Due to the difficulty of applying BMD, colistin resistance data are insufficient globally. Continuous epidemiological studies and validation of alternative methods are needed.

Molecular detection of extended-spectrum β-lactamase- and carbapenemase-producing Klebsiella pneumoniae isolates in southwest Iran

OBJECTIVE

The global emergence of carbapenem-resistant Klebsiella pneumoniae is considered a significant contemporary concern., as carbapenems are the last resort for treating infections caused by multidrug-resistant Gram-negative bacteria. This study aimed to investigate the carbapenem-resistance genes in extended-spectrum β-lactamase producing K. pneumoniae isolates.

METHODS

Seventy-five non-duplicate clinical K. pneumoniae strains were isolated from urine, blood, sputum, and wound samples. Antimicrobial susceptibility tests for 12 different antibiotics were performed using the disk diffusion method, followed by determining minimum inhibitory concentrations of imipenem and meropenem. Phenotypic detection of extended-spectrum β-lactamase and carbapenemase enzymes was performed by double-disc synergy test and modified Hodge test, respectively. PCR assay further investigated resistant isolates for extended-spectrum β-lactamase and carbapenemase-encoding genes.

RESULTS

The highest and lowest resistance rates were observed against ampicillin (93.3%) and tigecycline (9.3%). According to phenotypic tests, 46.7% of isolates were positive for extended-spectrum β-lactamase enzymes and 52.8% for carbapenemase. A total of 11 isolates contained carbapenemase genes, with blaOXA-48 (19.4%; 7/36) being the predominant gene, followed by blaNDM (8.3%; 3/36).

CONCLUSION

The study's findings reveal the alarming prevalence of beta-lactamase enzymes in K. pneumoniae strains. Early detection of carbapenem-resistant isolates and effective infection control measures are necessary to minimise further spread, as carbapenem resistance has become a public health concern.

Molecular Characterization of Carbapenem and Colistin Resistance in Klebsiella pneumoniae Isolates Obtained from Clinical Samples at a University Hospital Center in Algeria

The current study aimed to determine the molecular mechanisms of carbapenem and colistin resistance among the clinical isolates of Klebsiella pneumoniae from hospitalized patients admitted to a university hospital in Eastern Algeria. In total, 124 non-duplicate isolates of K. pneumoniae were collected from September 2018 to April 2019. Bacterial identification was performed using MALDI-TOF MS. The presence of extended spectrum β-lactamase (ESBL) genes, carbapenemase genes, chromosomal mutation and mcr genes in colistin-resistant K. pneumoniae were evaluated by PCR. ESBLs represented a rate of 49.1% and harbored blaCTX-M, blaTEM and blaSHV genes. Concerning carbapenems, 12 strains (9.6%) were resistant to ertapenem (MIC: 1-32 μg/mL), of which one strain (0.8%) was also resistant to imipenem (MIC: 32 μg/mL). Among these strains, nine (75%) harbored blaOXA-48 gene. Seven strains (5.6%) expressed resistance to colistin (MIC: 2-32 μg/mL), of which two harbored mcr-8 and mgrB genes simultaneously. The existence of a double resistance to colistin in the same strain is new in Algeria, and this could raise concerns about the increase in levels of resistance to this antibiotic (MIC: 32 μg/mL). The mgrB gene alone was observed in five isolates (71.4%), including two strains harboring blaOXA-48. This is the first report revealing the presence of K. pneumoniae strains carrying the blaOXA-48 gene as well as a mutation in the mgrB gene. Large-scale surveillance and effective infection control measures are also urgently needed to prevent the outbreak of various carbapenem- and colistin-resistant isolates.

Molecular characterization and epidemiological investigation of colistin resistance in carbapenem-resistant Klebsiella pneumoniae in a tertiary care hospital in Tehran, Iran

BACKGROUND

Carbapenemase-producing Klebsiella pneumoniae (CRKP) presents a significant challenge to antimicrobial therapy, especially when compounded by resistance to colistin. The objective of this study was to explore molecular epidemiological insights into strains of clinical K. pneumoniae that produce carbapenemases and exhibit resistance to colistin. Eighty clinical isolates of CRKP were obtained from Milad Hospital in Tehran, Iran. Antimicrobial susceptibility and colistin broth disk elution were determined. PCR assays were conducted to examine the prevalence of resistance-associated genes, including blaKPC, blaIMP, blaVIM, blaOXA-48, blaNDM and mcr-1 to -10. Molecular typing (PFGE) was used to assess their spread.

RESULTS

Colistin resistance was observed in 27 isolates (33.7%) using the Broth Disk Elution method. Among positive isolates for carbapenemase genes, the most frequent gene was blaOXA-48, identified in 36 strains (45%). The mcr-1 gene was detected in 3.7% of the obtained isolates, with none of the other of the other mcr genes detected in the studied isolates.

CONCLUSION

To stop the spread of resistant K. pneumoniae and prevent the evolution of mcr genes, it is imperative to enhance surveillance, adhere rigorously to infection prevention protocols, and implement antibiotic stewardship practices.

Global prevalence of mutation in the mgrB gene among clinical isolates of colistin-resistant Klebsiella pneumoniae: a systematic review and meta-analysis

Background

Colistin is used as a last resort for managing infections caused by multidrug-resistant bacteria. However, the high emergence of colistin-resistant strains has restricted the clinical use of this antibiotic in the clinical setting. In the present study, we evaluated the global prevalence of the mutation in the mgrB gene, one of the most important mechanisms of colistin resistance in Klebsiella pneumoniae.

Methods

Several databases, including Scopus, Medline (via PubMed), and Web of Science, were searched (until August 2023) to identify those studies that address the mgrB mutation in clinical isolates of K. pneumoniae. Using Stata software, the pooled prevalence of mgrB mutation and subgroup analyses for the year of publication, country, continent, mgrB mutation types, and detection methods of mgrB mutation were analyzed.

Results

Out of the 115 studies included in the analysis, the prevalence of mgrB mutations in colistin-resistant K. pneumoniae isolates was estimated at 65% of isolates, and mgrB variations with insertional inactivation had the highest prevalence among the five investigated mutations with 69%. The year subgroup analysis indicated an increase in mutated mgrB from 46% in 2014 to 61% in 2022. Europe had the highest prevalence of mutated mgrB at 73%, while Africa had the lowest at 54%.

Conclusion

Mutations in the mgrB gene are reported as one of the most common mechanisms of colistin resistance in K. pneumoniae, and the results of the present study showed that 65% of the reported colistin-resistant K. pneumoniae had a mutation in this gene.

Prevalence and epidemiological investigation of mgrB-dependent colistin resistance in extensively drug resistant Klebsiella pneumoniae in Iran

Carbapenemases-producing K. pneumoniae are challenging antimicrobial therapy of hospitalised patients, which is further complicated by colistin resistance. The aim of this study was to investigate the molecular epidemiological insights into carbapenemases-producing and colistin-resistant clinical K. pneumoniaeA total of 162 colistin resistant clinical strains of K. pneumoniae were collected during 2017-2019. Antimicrobial susceptibility and the colistin minimum inhibitory concentration were determined. Using PCR assay, the prevalence of resistance-associated genes including blaKPC, blaIMP, blaVIM, blaOXA-48, blaNDM-1 and mcr-1 to -9 was examined. Additionally, a PCR assay was used to examine the mgrB gene in colistin-resistant bacteria. 94.4% of the tested strains were resistant to imipenem and 96.3% were resistant to meropenem. Colistin resistance (MIC > 4 µg/L) was observed in 161 isolates (99.4%) by Colistin Broth Disk Elution method. The KPC enzyme was the most common carbapenemase and was identified in 95 strains (58.6%), followed by the IMP, VIM and OXA-48 detected in 47 (29%), 23 (14.2%) and 12 (7.4%) isolates, respectively. However, no NDM-1 gene was detected. Additionally, none of the studied isolates harbored mcr variants, while mgrB gene was observed in 152 (92.6%) isolates. Colistin resistance of K. pneumoniae isolates may be associated with mgrB gene mutation. To stop the spread of resistant K. pneumoniae, surveillance must be improved, infection prevention protocols must be followed, and antibiotic stewardship must be practised.

Prevalence of Multidrug-Resistant Pathogens Causing Neonatal Early and Late Onset Sepsis, a Retrospective Study from the Tertiary Referral Children's Hospital

Introduction

Sepsis is the most severe infectious disease with the highest mortality rate, particularly among neonates admitted to the neonatal intensive care unit (NICU). This study retrospectively analyzed the epidemiology, antibiotic resistance profiles, and prevalence of multidrug-resistant (MDR) bacteria isolated from blood or cerebrospinal fluid (CSF) cultures in order to evaluate the appropriateness of initial empirical therapy for neonatal sepsis.

Methods

A retrospective study was conducted in the NICU from January 1, 2015, to December 31, 2022. Microbiological data from patients admitted to the NICU were anonymously extracted from the Laboratory of Microbiology database. Neonatal sepsis was classified into two types: early-onset sepsis (EOS), which occurs within the first 72 hours of life, and late-onset sepsis (LOS) for those begins later.

Results

A total of 679 bacterial strains, 543 from blood and 136 from CSF, were detected in 631 neonates. Among these, 378 isolates (55.67%) were Gram-positive bacteria, and 301 isolates (44.33%) were Gram-negative bacteria. The most frequently isolated pathogens were Coagulase-negative staphylococci (CoNS) (36.52%), followed by Klebsiella pneumoniae (20.47%) and Escherichia coli (13.84%). In EOS, 121 strains were found, CoNS represented the majority (33.88%), followed by Klebsiella pneumoniae (23.97%) and Escherichia coli (8.26%). Early-onset septicemia exhibited 67 (55.37%) MDR bacteria. In LOS, 558 strains were isolated, CoNS represented the majority of pathogens (37.10%), followed by Klebsiella pneumoniae (19.71%) and Escherichia coli (15.05%). Late-onset septicemia showed 332 (59.50%) MDR bacteria. High rates of MDR were found in CoNS (76.21%), carbapenem-resistant Klebsiella pneumoniae (66.91%), and MRSA (33.33%).

Conclusion

The study revealed an alarming prevalence of MDR strains isolated from neonatal sepsis, emphasizing the necessity of finding effective prevention and treatment measures. Colistin can be used for MDR Gram-negative bacteria, while vancomycin and teicoplanin can be considered treatment therapies for staphylococcal infections.

Epidemiology and mortality outcome of carbapenem- and colistin-resistant Klebsiella pneumoniae, Escherichia coli, Acinetobacter baumannii, and Pseudomonas aeruginosa bloodstream infections

BACKGROUND

Bloodstream infections caused by carbapenem-resistant Gram-negative bacteria represent a major therapeutic challenge to clinicians worldwide. This study examined the epidemiology of carbapenem and colistin resistance in Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii blood isolates in an academic institution in Oman.

METHODS

Adult patients with bloodstream infections caused by Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii, between January 1, 2017, and December 31, 2020, were identified. Rates of carbapenem resistance, carbapenem-colistin dual resistance, and 30-day all-cause mortality were examined.

RESULTS

585 non-repeat bloodstream infections due to Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii were identified during the study period. OXA-48 was the most prevalent carbapenemase gene in carbapenem-resistant K. pneumoniae blood isolates. Carbapenem resistance was observed in 160 (27.7%) of blood isolates, with 131 (81.9%) of these being healthcare-onset cases. Carbapenem resistance was highest in Acinetobacter baumannii (80.4%), followed by Klebsiella pneumoniae (46.4%), and Pseudomonas aeruginosa (29.9%). Sixteen (13.4%) of the carbapenem-resistant blood isolates were found to be colistin resistant. Thirty-day all-cause mortality was 68.1% in patients with bloodstream infections caused by carbapenem-resistant isolates, versus 21.3% in patients with bloodstream infections caused by carbapenem-susceptible isolates.

CONCLUSION

The prevalence of carbapenem resistance and carbapenem-colistin dual resistance in Gram-negative blood culture isolates from patients with bloodstream infections is unacceptably high. Patients with bloodstream infections due to carbapenem-resistant isolates had substantially higher mortality.

Polymyxin combination therapy for multidrug-resistant, extensively-drug resistant, and difficult-to-treat drug-resistant gram-negative infections: is it superior to polymyxin monotherapy?

INTRODUCTION

The increasing prevalence of infections with multidrug-resistant (MDR), extensively-drug resistant (XDR) or difficult-to-treat drug resistant (DTR) Gram-negative bacilli (GNB), including Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Enterobacter species, and Escherichia coli poses a severe challenge.

AREAS COVERED

The rapid growing of multi-resistant GNB as well as the considerable deceleration in development of new anti-infective agents have made polymyxins (e.g. polymyxin B and colistin) a mainstay in clinical practices as either monotherapy or combination therapy. However, whether the polymyxin-based combinations lead to better outcomes remains unknown. This review mainly focuses on the effect of polymyxin combination therapy versus monotherapy on treating GNB-related infections. We also provide several factors in designing studies and their impact on optimizing polymyxin combinations.

EXPERT OPINION

An abundance of recent in vitro and preclinical in vivo data suggest clinical benefit for polymyxin-drug combination therapies, especially colistin plus meropenem and colistin plus rifampicin, with synergistic killing against MDR, XDR, and DTR P. aeruginosa, K. pneumoniae and A. baumannii. The beneficial effects of polymyxin-drug combinations (e.g. colistin or polymyxin B + carbapenem against carbapenem-resistant K. pneumoniae and carbapenem-resistant A. baumannii, polymyxin B + carbapenem + rifampin against carbapenem-resistant K. pneumoniae, and colistin + ceftolozan/tazobactam + rifampin against PDR-P. aeruginosa) have often been shown in clinical setting by retrospective studies. However, high-certainty evidence from large randomized controlled trials is necessary. These clinical trials should incorporate careful attention to patient's sample size, characteristics of patient's groups, PK/PD relationships and dosing, rapid detection of resistance, MIC determinations, and therapeutic drug monitoring.

Clonal transmission of polymyxin B-resistant hypervirulent Klebsiella pneumoniae isolates coharboring blaNDM-1 and blaKPC-2 in a tertiary hospital in China

BACKGROUND

The prevalence of multidrug-resistant hypervirulent K. pneumoniae (MDR-hvKP) has gradually increased. It poses a severe threat to human health. However, polymyxin-resistant hvKP is rare. Here, we collected eight polymyxin B-resistant K. pneumoniae isolates from a Chinese teaching hospital as a suspected outbreak.

RESULTS

The minimum inhibitory concentrations (MICs) were determined by the broth microdilution method. HvKP was identified by detecting virulence-related genes and using a Galleria mellonella infection model. Their resistance to serum, growth, biofilm formation, and plasmid conjugation were analyzed in this study. Molecular characteristics were analyzed using whole-genome sequencing (WGS) and mutations of chromosome-mediated two-component systems pmrAB and phoPQ, and the negative phoPQ regulator mgrB to cause polymyxin B (PB) resistance were screened. All isolates were resistant to polymyxin B and sensitive to tigecycline; four were resistant to ceftazidime/avibactam. Except for KP16 (a newly discovered ST5254), all were of the K64 capsular serotype and belonged to ST11. Four strains co-harbored bla_KPC-2, bla_NDM-1, and the virulence-related genes _prmpA, _prmpA2, iucA, and peg344, and were confirmed to be hypervirulent by the G. mellonella infection model. According to WGS analysis, three hvKP strains showed evidence of clonal transmission (8-20 single nucleotide polymorphisms) and had a highly transferable pKOX_NDM1-like plasmid. KP25 had multiple plasmids carrying bla_KPC-2, bla_NDM-1, bla_SHV-12, bla_LAP-2, tet(A), fosA5, and a pLVPK-like virulence plasmid. Tn1722 and multiple additional insert sequence-mediated transpositions were observed. Mutations in chromosomal genes phoQ and pmrB, and insertion mutations in mgrB were major causes of PB resistance.

CONCLUSIONS

Polymyxin-resistant hvKP has become an essential new superbug prevalent in China, posing a serious challenge to public health. Its epidemic transmission characteristics and mechanisms of resistance and virulence deserve attention.

Fighting Antimicrobial Resistance in Neonatal Intensive Care Units: Rational Use of Antibiotics in Neonatal Sepsis

Antibiotics are the most frequently prescribed drugs in neonatal intensive care units (NICUs) due to the severity of complications accompanying neonatal sepsis. However, antimicrobial drugs are often used inappropriately due to the difficulties in diagnosing sepsis in the neonatal population. The reckless use of antibiotics leads to the development of resistant strains, rendering multidrug-resistant pathogens a serious problem in NICUs and a global threat to public health. The aim of this narrative review is to provide a brief overview of neonatal sepsis and an update on the data regarding indications for antimicrobial therapy initiation, current guidance in the empirical antimicrobial selection and duration of therapy, and indications for early discontinuation.

Antimicrobial resistance and molecular characterization of Klebsiella species causing bovine mastitis in Nghe An province, Vietnam

Objectives

This study aimed to determine the antibiotic-resistant profile and to identify molecular characterization of some virulence genes of Klebsiella spp. isolated from mastitis samples in Vietnam.

Materials and Method

A total of 468 samples from clinical mastitis cases were collected and submitted to the Laboratory. All samples were cultured, and Klebsiella spp. was identified through biochemical reactions and confirmed by Polymerase chain reaction (PCR). Antimicrobial resistance was tested by disk diffusion method, and virulence and resistance genes were tested by PCR.

Results

An antibiogram study showed that a high proportion of isolates are multidrug-resistant (94%). All isolates were resistant to lincomycin and sulfamethoxazole, followed by ampicillin (94%), sulphonamide (66%), amoxicillin (56%), streptomycin (52%), polymyxin B (28%), colistin sulfate (12%), tetracycline (6%), ciprofloxacin (4%), florfenicol (4%), enrofloxacin (4%), piperacillin (2%), trimethoprim (2%), nalidixic acid (2%), imipenem (2%), and sulfamethoxazole/trimethoprim (2%). In contrast, all isolates showed sensitivity to gentamicin and ceftiofur. The appearance of an efflux pump system, extended-spectrum beta-lactamase (ESBL), tetracycline, and sulphonamides-resistant genes was reconfirmed using different specific primers. Capsular serotype K1 and virulence genes magA, fimH, and entB, responsible for hypermucoviscosity production, adherence, and enterobactin production, were confirmed in isolates. Multidrug resistance and virulence potential in Klebsiella spp. are changing this mastitis pathogen into a superbug and making its management harder.

Conclusions

Klebsiella spp. associated with bovine mastitis in Nghe An province were mostly multidrug-resistant and carried virulence genes including fimH, entB, and antimicrobials resistant genes (bla _SHV, acrA_Kp, tetA, etc.), but these isolates were not ESBL producers.

Prevalence of Mutated Colistin-Resistant Klebsiella pneumoniae: A Systematic Review and Meta-Analysis

The emergence of genetic mutations in chromosomal genes and the transmissible plasmid-mediated colistin resistance gene may have helped in the spread of colistin resistance among various Klebsiella pneumoniae (K. pneumoniae) isolates and other different bacteria. In this study, the prevalence of mutated colistin-resistant K. pneumoniae isolates was studied globally using a systematic review and meta-analysis approach. A systematic search was conducted in databases including PubMed, ScienceDirect, Scopus and Google Scholar. The pooled prevalence of mutated colistin resistance in K. pneumoniae isolates was analyzed using Comprehensive Meta-Analysis Software (CMA). A total of 50 articles were included in this study. The pooled prevalence of mutated colistin resistance in K. pneumoniae was estimated at 75.4% (95% CI = 67.2−82.1) at high heterogeneity (I2 = 81.742%, p-value < 0.001). Meanwhile, the results of the subgroup analysis demonstrated the highest prevalence in Saudi Arabia with 97.9% (95% CI = 74.1−99.9%) and Egypt, with 4.5% (95% CI = 0.6−26.1%), had the lowest. The majority of mutations could be observed in the mgrB gene (88%), pmrB gene (54%) and phoQ gene (44%). The current study showed a high prevalence of the mutation of colistin resistance genes in K. pneumoniae. Therefore, it is recommended that regular monitoring be performed to control the spread of colistin resistance.

Problems Associated with Co-Infection by Multidrug-Resistant Klebsiella pneumoniae in COVID-19 Patients: A Review

To date, coronavirus disease 2019 (COVID-19) and its variants have been reported as a novel public health concern threatening us worldwide. The presence of Klebsiella pneumoniae in COVID-19-infected patients is a major problem due to its resistance to multiple antibiotics, and it can possibly make the management of COVID-19 in patients more problematic. The impact of co-infection by K. pneumoniae on COVID-19 patients was explored in the current review. The spread of K. pneumoniae as a co-infection among critically ill COVID-19 patients, particularly throughout hospitalization, was identified and recorded via numerous reports. Alarmingly, the extensive application of antibiotics in the initial diagnosis of COVID-19 infection may reduce bacterial co-infection, but it increases the antibiotic resistance of bacteria such as the strains of K. pneumoniae. The correct detection of multidrug-resistant K. pneumoniae can offer a supportive reference for the diagnosis and therapeutic management of COVID-19 patients. Furthermore, the prevention and control of K. pneumoniae are required to minimize the risk of COVID-19. The aim of the present review is, therefore, to report on the virulence factors of the K. pneumonia genotypes, the drug resistance of K. pneumonia, and the impact of K. pneumoniae co-infection with COVID-19 on patients through a study of the published scientific papers, reports, and case studies.