Virulence factors and antibiotic susceptibility patterns of multidrug resistance Klebsiella pneumoniae isolated from different clinical infections

Virulence Factors in Klebsiella pneumoniae: A Literature Review

Klebsiella pneumoniae, a member of the autochthonous human gut microbiota, utilizes a variety of virulence factors for survival and pathogenesis. Consequently, it is responsible for several human infections, including urinary tract infections, respiratory tract infections, liver abscess, meningitis, bloodstream infections, and medical device-associated infections. The main studied virulence factors in K. pneumoniae are capsule-associated, fimbriae, siderophores, Klebsiella ferric iron uptake, and the ability to metabolize allantoin. They are crucial for virulence and were associated with specific infections in the mice infection model. Notably, these factors are also prevalent in strains from the same infections in humans. However, the type and quantity of virulence factors may vary between strains, which defines the degree of pathogenicity. In this review, we summarize the main virulence factors investigated in K. pneumoniae from different human infections. We also cover the specific identification genes and their prevalence in K. pneumoniae, especially in hypervirulent strains.

Proteome analysis, genetic characterization, and antibiotic resistance patterns of Klebsiella pneumoniae clinical isolates

Klebsiella pneumoniae (K. pneumoniae) is a member of the ESKAPE group and is responsible for severe community and healthcare-associated infections. Certain Klebsiella species have very similar phenotypes, which presents a challenge in identifying K. pneumoniae. Multidrug-resistant K. pneumoniae is also a serious global problem that needs to be addressed. A total of 190 isolates were isolated from urine (n = 69), respiratory (n = 52), wound (n = 48) and blood (n = 21) samples collected from various hospitals in the Al-Qassim, Saudi Arabia, between March 2021 and October 2022. Our study aimed to rapidly and accurately detect K. pneumoniae using the Peptide Mass Fingerprinting (PMF) technique, confirmed by real-time PCR. Additionally, screening for antibiotic susceptibility and resistance was conducted. The primary methods for identifying K. pneumoniae isolates were culture, Gram staining, and the Vitek® 2 ID Compact system. An automated MALDI Biotyper (MBT) instrument was used for proteome identification, which was subsequently confirmed using SYBR green real-time polymerase chain reaction (real-time PCR) and microfluidic electrophoresis assays. Vitek® 2 AST-GN66 cards were utilized to evaluate the antimicrobial sensitivity of K. pneumoniae isolates. According to our results, Vitek® 2 Compact accurately identified 178 out of 190 (93.68%) K. pneumoniae isolates, while the PMF technique correctly detected 188 out of 190 (98.95%) isolates with a score value of 2.00 or higher. Principal component analysis was conducted using MBT Compass software to classify K. pneumoniae isolates based on their structure. Based on the analysis of the single peak intensities generated by MBT, the highest peak values were found at 3444, 5022, 5525, 6847, and 7537 m/z. K. pneumoniae gene testing confirmed the PMF results, with 90.53% detecting entrobactin, 70% detecting 16 S rRNA, and 32.63% detecting ferric iron uptake. The resistance of the K. pneumoniae isolates to antibiotics was as follows: 64.75% for cefazolin, 62.63% for trimethoprim/sulfamethoxazole, 59.45% for ampicillin, 58.42% for cefoxitin, 57.37% for ceftriaxone, 53.68% for cefepime, 52.11% for ampicillin-sulbactam, 50.53% for ceftazidime, 52.11% for ertapenem, and 49.47% for imipenem. Based on the results of the double-disk synergy test, 93 out of 190 (48.95%) K. pneumoniae isolates were extended-spectrum beta-lactamase. In conclusion, PMF is a powerful analytical technique used to identify K. pneumoniae isolates from clinical samples based on their proteomic characteristics. K. pneumoniae isolates have shown increasing resistance to antibiotics from different classes, including carbapenem, which poses a significant threat to human health as these infections may become difficult to treat.

Crippling of Klebsiella pneumoniae virulence by metformin, N-acetylcysteine and secnidazole

INTRODUCTION

The emergence of multidrug-resistant Klebsiella pneumoniae in hospitals represents a serious threat to public health. Infections caused by Klebsiella pneumoniae are widespread in healthcare institutions, mainly pneumonia, bloodstream infections, and infections affecting neonates in intensive care units; so, it is necessary to combat this pathogen with new strategies. Targeting virulence factors necessary to induce host damage and disease is a new paradigm for antimicrobial therapy with several potential benefits that could lead to decreased resistance.

BACKGROUND

The influence of metformin, N-acetylcysteine, and secnidazole on Klebsiella pneumoniae virulence factors production was tested. The production of Klebsiella pneumoniae virulence factors such as biofilm formation, urease, proteases, hemolysins, and tolerance to oxidative stress was evaluated phenotypically using sub-inhibitory concentration (1/8 MIC) of metformin, N-acetylcysteine, and secnidazole. For more confirmation, qRT-PCR was used to assess the relative expression level of rmpA, wcaG, fimH-1, mrkD, ureA, and khe genes regulating virulence factors production.

RESULTS

Metformin, N-acetylcysteine, and secnidazole were all found to have a powerful inhibitory effect on the production of virulence factors phenotypically. Our results showed a significant reduction in the expression level of rmpA, wcaG, fimH-1, mrkD, ureA, and khe genes. Furthermore, the tested drugs were investigated in vivo to inform their ability to protect mice against Klebsiella pneumoniae pathogenesis.

CONCLUSIONS

Metformin, N-acetylcysteine, and secnidazole inhibited the virulence of Klebsiella pneumoniae. Besides combating resistant Klebsiella pneumoniae, the tested drugs could also serve as an adjuvant to traditional antibiotics.

Recent Trends and Developments in Multifunctional Nanoparticles for Cancer Theranostics

Conventional anticancer treatments, such as radiotherapy and chemotherapy, have significantly improved cancer therapy. Nevertheless, the existing traditional anticancer treatments have been reported to cause serious side effects and resistance to cancer and even to severely affect the quality of life of cancer survivors, which indicates the utmost urgency to develop effective and safe anticancer treatments. As the primary focus of cancer nanotheranostics, nanomaterials with unique surface chemistry and shape have been investigated for integrating cancer diagnostics with treatment techniques, including guiding a prompt diagnosis, precise imaging, treatment with an effective dose, and real-time supervision of therapeutic efficacy. Several theranostic nanosystems have been explored for cancer diagnosis and treatment in the past decade. However, metal-based nanotheranostics continue to be the most common types of nonentities. Consequently, the present review covers the physical characteristics of effective metallic, functionalized, and hybrid nanotheranostic systems. The scope of coverage also includes the clinical advantages and limitations of cancer nanotheranostics. In light of these viewpoints, future research directions exploring the robustness and clinical viability of cancer nanotheranostics through various strategies to enhance the biocompatibility of theranostic nanoparticles are summarised.

Distribution of CTX-M, TEM, SHV Beta-lactamase Gene among the Klebsiella pneumoniae Clinical Isolates from Tertiary Care Centre in Palakkad, Kerala

Resistance against the routinely used antibiotics has reached a worrying level globally. Extended spectrum β-lactamases (ESBLs) production is the major mechanism of antimicrobial resistance. These ESBLs bacteria are resistance to penicillin, cephalosporins, monobactams. TEM1&2, CTX-M, SHV are the main ESBLs genes present in Klebsiella pneumoniae, which is produced by the alteration of amino acid in the active site. The aim of this study is to determine the prevalence of ESBL genes such as blaTEM 1&2, blaCTX-M and blaSHV. The present study was carried out from April 2019 to September 2019, a total of 121 K. pneumoniae isolates were collected and subjected to phenotypic study. Among these 19 isolated was ESBL positive, genes (blaSHV, blaTEM, blaCTX-M) were detected by conventional PCR method. blaTEM (100%) was the predominant gene detected flowed by CTX-M (68.42%) and SHV (57.89%). The highest level of antimicrobial resistance towards ampicillin (93.4%) followed by ceftriaxone (28.9%), cefotaxime (24.8%) and ciprofloxacin (22.3%). However, ESBL-producing isolates were showed resistance to ampicillin (100%) followed by ceftazidime (94.74%), cefotaxime (89.47%), amikacin and amoxicillin-clavulanic acid (68%). Antimicrobial resistance of bacteria is due to the genes, especially extended spectrum beta lactamase, which is widely found in members of Enterobacteriaceae. Nevertheless, there is a paucity of studies regarding the distribution of ESBL in K. pneumoniae in Palakkad Dist., Kerala. Hence the aim of the current study determines the distribution of ESBL genes in ESBL producing K. pneumoniae isolated from various clinical samples.

Identification and Characterization of Plasmids and Genes from Carbapenemase-Producing Klebsiella pneumoniae in Makkah Province, Saudi Arabia

Klebsiella pneumoniae (K. pneumoniae) is involved in several hospital and community-acquired infections. The prevalence of K. pneumoniae-producing-carbapenemase (KPC) resistance genes rapidly increases and threatens public health worldwide. This study aimed to assess the antibiotic resistance level of K. pneumoniae isolates from Makkah Province, Saudi Arabia, during the Islamic ‘Umrah’ ritual and to identify the plasmid types, presence of genes associated with carbapenem hydrolyzing enzymes, and virulence factors. The phenotypic and genotypic analyses based on the minimum inhibitory concentration (MIC), biofilm formation, PCR, and characterization of KPC-encoding plasmids based on the replicon typing technique (PBRT) were explored. The results showed that most isolates were resistant to carbapenem antibiotics and other antibiotics classes. This study identified sixteen different replicons of plasmids in the isolates and multiple genes encoding carbapenem factors, with blaVIM and blaOXA-48 being the most prevalent genes identified in the isolates. However, none of the isolates exhibited positivity for the KPC production activity. In addition, this study also identified six virulence-related genes, including kfu, wabG, uge, rmpA, fimH, and a capsular polysaccharide (CPS). Together, the data reported in this study indicate that the isolated K. pneumoniae during the pilgrimage in Makkah were all resistant to carbapenem antibiotics. Although the isolates lacked KPC production activity, they carried multiple carbapenem-resistant genes and virulence factors, which could drive their resistant phenotype. The need for specialized methods for KPC detection, monitoring the possibility of nosocomial transmission, and diverse therapeutic alternatives are necessary for controlling the spreading of KPC. This study can serve as a reference for clinicians and researchers on types of K. pneumoniae commonly found during religious gathering seasons in Saudi Arabia.

Phenotypic Characterization of Virulence Factors and Antibiogram of Klebsiella pneumoniae Isolates from Various Clinical Samples – A Cross Sectional Study

K. pneumoniae is known to cause hospital and community acquired infections. It is usually associated with upper & lower respiratory infections, septicaemia, urinary tract infection, wound infections, neonatal sepsis, meningitis, and endophthalmitis. The virulence factors play a role in its existence in different environmental conditions and therefore help in establishing Klebsiella pneumoniae infection in the human body. Multi drug resistant Klebsiella pneumoniae is an increasing threat to human health. Klebsiella pneumoniae is one of the species recognized as nosocomial pathogens that exhibit multidrug resistance and virulence in ESKAPE group as per WHO. The study was conducted to determine the various virulence factors & the antimicrobial pattern of Klebsiella pneumoniae isolates. A cross sectional observational study, conducted in Department of Microbiology of R.L. Jalappa Hospital and Research Centre, Kolar, Sample size of 150. All 150 Klebsiella pneumoniae isolates collected for the study, The Klebsiella pneumoniae isolates which were positive for various virulence factors were as follows on hemolysis 7(4.66%), capsule 150(100%), Hypermucoviscosity formation 66(44%), biofilm production 81(54%), siderophore production 110(73.33%), protease 135(90%), gelatinase 126(84%), lipase production 119(79.33%), lecithinase activity 82(54.66%). The drug resistance klebsiella pneumoniae were as follows: ESBL producers 24(16.67%), AmpC producers were 22(14.67%), MDR 116(74.20%), extensive drug resistant (XDR) 30(20%), pan drug resistant (PDR) 42(28%), Carbapenem resistance 65.33% reported. The increasing coexistence of virulence factors & antimicrobial resistance pattern is of particular concern. Hence active surveillance for antimicrobial resistance & virulence determinants is imperative now to implement effective control measures to prevent the rapid spread of drug resistance.

Determination of extended-spectrum β-lactamase-producing Klebsiella pneumoniae isolated from horses with respiratory manifestation

Background and Aim:

The World Health Organization considers multidrug-resistant (MDR) Klebsiella pneumoniae a major global threat. Horses harbor commensal isolates of this bacterial species and potentially serve as reservoirs for human MDR bacteria. This study investigated antimicrobial resistance in horses caused by extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae.

Materials and Methods:

One hundred fifty-nine nasal swab samples were collected from horses with respiratory distress not treated with cefotaxime and erythromycin. Biochemical and serological identification was performed on all samples. Polymerase chain reaction (PCR) was used to detect 16S-23S ITS, mucoviscosity-associated gene (magA), uridine diphosphate galacturonate 4-epimerase gene (uge), and iron uptake system gene (kfu), bla_TEM, bla_SHV, and bla_CTX genes. Sequence analysis and phylogenetic relatedness of randomly selected K. pneumoniae isolates carrying the bla_TEM gene were performed.

Results:

Ten isolates of Klebsiella spp. were obtained from 159 samples, with an incidence of 6.28% (10 of 159). Based on biochemical and serological identification, K. pneumoniae was detected in 4.4% (7 of 159) of the samples. Using PCR, all tested K. pneumoniae isolates (n=7) carried the 16S-23S ITS gene. By contrast, no isolates carried magA, uge, and kfu genes. The bla_TEM gene was detected in all test isolates. Moreover, all isolates did not harbor the bla_SHV or bla_CTX gene. Sequence analysis and phylogenetic relatedness reported that the maximum likelihood unrooted tree generated indicated the clustering of the test isolate with the other Gram-negative isolate bla_TEM. Finally, the sequence distance of the bla_TEM gene of the test isolate (generated by Lasergene) showed an identity range of 98.4-100% with the bla_TEM gene of the different test isolates.

Conclusion:

The misuse of antimicrobials and insufficient veterinary services might help generate a population of ESBL-producing K. pneumoniae in equines and humans, representing a public health risk.

Molecular prevalence of resistance determinants, virulence factors and capsular serotypes among colistin resistance carbapenemase producing Klebsiella pneumoniae: a multi-centric retrospective study

The emergence of colistin-carbapenem-resistant Klebsiella pneumoniae (CCR-Kp) in bloodstream infection results in high mortality, and virulence factor contributes further to the difficulty of treatment. A total of 158 carbapenem-resistant K. pneumoniae (CRKP) isolates causing bloodstream infection were collected from three Indian tertiary care hospitals during the 9-month study period, of which 27 isolates exhibited resistance to both colistin and carbapenem antibiotics. In this study, all the strains were characterized for antimicrobial resistance, virulence factors and capsular serotypes that facilitate the development of colistin and carbapenem-resistant K.pneumoniae (CCR-Kp) in bloodstream infection. Fourteen isolates displayed extremely drug resistance (XDR), susceptible only to tigecycline, and the remaining 13 isolates displayed multidrug resistance (MDR). The gene prevalence analysis for CCR-Kp isolates showed the predominance of bla KPC (81.48%) followed by bla NDM (62.96%), bla VIM (37.03%) and bla IMP (18.51%) genes. The distribution of virulence genes was found to be fimH (81.48%), wabG (59.25%), mrkD (55.56%), entB (48.15%), irp1 (33.33%), and rmpA (18.52%). The capsular serotypes K1, K2, K5 and K54 have been identified in 16 isolates. The absence of plasmid-mediated colistin resistance (mcr) genes implies the involvement of other mechanisms. The ERIC and (GTG)5 molecular typing methods detected 18 and 22 distinct clustering patterns among the CCR-Kp isolates, respectively. A strong correlation between ERIC and (GTG)5 genotyping method was established with antimicrobial resistance patterns and virulence determinants at P < 0.05, while no correlation was found with capsular serotyping. Similar virulence and resistance typing among the isolates suggest hospital-acquired infection in a health care setup. These outcomes will advance our awareness of CCR-Kp outbreaks associated with tertiary care hospitals and help forecast their occurrence in the near future.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-03056-4.

Global Prevalence of Nosocomial Multidrug-Resistant Klebsiella pneumoniae: A Systematic Review and Meta-Analysis

The emergence of nosocomial multidrug-resistant Klebsiella pneumoniae is an escalating public health threat worldwide. The prevalence of nosocomial infections due to K. pneumoniae was recorded up to 10%. In this systematic review and meta-analysis, which were conducted according to the guidelines of Preferred Reporting Items for Systematic Review and Meta-Analysis, 1092 articles were screened from four databases of which 47 studies fulfilled the selected criteria. By performing a random-effect model, the pooled prevalence of nosocomial multidrug-resistant K. pneumoniae was estimated at 32.8% (95% CI, 23.6-43.6), with high heterogeneity (I2 98.29%, p-value < 0.001). The estimated prevalence of this pathogen and a few related studies were discussed, raising awareness of the spread of multidrug-resistant K. pneumoniae in the healthcare setting. The emergence of nosocomial multidrug-resistant K. pneumoniae is expected to increase globally in the future, and the best treatments for treating and preventing this pathogen should be acknowledged by healthcare staff.

Non-thermal Plasma Treatment of ESKAPE Pathogens: A Review

The acronym ESKAPE refers to a group of bacteria consisting of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. They are important in human medicine as pathogens that show increasing resistance to commonly used antibiotics; thus, the search for new effective bactericidal agents is still topical. One of the possible alternatives is the use of non-thermal plasma (NTP), a partially ionized gas with the energy stored particularly in the free electrons, which has antimicrobial and anti-biofilm effects. Its mechanism of action includes the formation of pores in the bacterial membranes; therefore, resistance toward it is not developed. This paper focuses on the current overview of literature describing the use of NTP as a new promising tool against ESKAPE bacteria, both in planktonic and biofilm forms. Thus, it points to the fact that NTP treatment can be used for the decontamination of different types of liquids, medical materials, and devices or even surfaces used in various industries. In summary, the use of diverse experimental setups leads to very different efficiencies in inactivation. However, Gram-positive bacteria appear less susceptible compared to Gram-negative ones, in general.

Virulence factors, antibiotic resistance patterns, and molecular types of clinical isolates of Klebsiella Pneumoniae

BACKGROUND

Klebsiella pneumoniae is armed with a wide range of antibiotic resistance mechanisms that mostly challenge effective treatment. The aims of the current study were to identify the clinical strains of K. pneumoniaealso to determine their phenotypes and molecular characterization related to antimicrobial resistance and virulence genes.

RESEARCH DESIGN AND METHODS

In this investigation, clinical specimens from different hospitals located in Tehran, Iran, were collected during a nine-month period (December 2018 to August 2019). The K. pneumoniae strains were isolated and identified through standard microbial and biochemical assays. Additionally, disk diffusion, combined disk, Modified Hodge Test (MHT) and PCR were performed for antibiotic resistance and virulence gene analysis, respectively.

RESULTS

Eighty-four isolates of K. pneumoniae were subjected to the study. According to the combined disk and modified Hodge test results, 27 (52%) and 15 pathotypes (62.5%) out of resistant strains of isolated K. pneumoniae were detected as ESBL and KPC producers. The virulence genes of mrkD (94%) and magA (11%) were the highest and lowest among isolates, respectively.

CONCLUSIONS

The high prevalence of antibiotic resistance and virulence genes in conjunction with a significant relationship between the strains revealed a high pathogenic capacity of the isolated pathotypes of K. pneumoniae.

Virulent and multidrug-resistant Klebsiella pneumoniae from clinical samples in Balochistan

Klebsiella pneumoniae is an important pathogen causing hospital-acquired infections in human beings. Samples from suspected patients of K pneumoniae associated with respiratory and urinary tract infections were collected at Bolan Medical Complex, Quetta, Balochistan. Clinical samples (n = 107) of urine and sputum were collected and processed for K pneumoniae isolation using selective culture media. Initially, 30 of 107 isolates resembling Klebsiella spp. were processed for biochemical profiling and molecular detection using gyrase A (gyrA) gene for conformation. The K pneumoniae isolates were analysed for the presence of drug resistance and virulence genes in their genomes. The 21 of 107 (19.6%) isolates were finally confirmed as K pneumoniae pathogens. An antibiogram study conducted against 17 different antibiotics showed that a majority of the isolates are multidrug resistant. All the isolates (100%) were resistant to amoxicillin, cefixime, amoxicillin-clavulanic acid, cefotaxime, and ceftriaxone followed by tetracycline (95.2%), ciprofloxacin and gentamicin (76.2%), sulphamethoxazol (66.7%), nalidixic acid (61.9%), norfloxacine (42.9%), piperacillin-tazobactam (23.8%), cefoperazone-sulbactam (19%), and cefotaxime-clavulanic acid (33.3%), whereas all the isolates showed sensitivity to amikacin, chloramphenicol, and imipenem. The presence of tetracycline, sulphamethoxazol-resistant genes, and extended-spectrum beta-lactamase was reconfirmed using different specific genes. The presence of virulence genes fimH1 and EntB responsible for adherence and enterobactin production was confirmed in the isolates. The high virulence and drug resistance potential of these Klebsiella isolates are of high public health concern. Multidrug resistance and virulence potential in K. pneumoniae are converting these nosocomial pathogens into superbugs and making its management harder.

From Turkey: First Report of KPC-3- and CTX-M-27-Producing Multidrug-Resistant Klebsiella pneumoniae ST147 Clone Carrying OmpK36 and Ompk37 Porin Mutations

Aim: The aim of this study was to identify antimicrobial resistance genes, virulence factor genes, and porin loss or mutations exhibited by the multidrug-resistant Klebsiella pneumoniae strain. Materials and Methods: Whole-genome sequencing was done via the Illumina NovaSeq 6000 platform. Strain identification and antibiotic susceptibility testing of strains were performed by the Vitek 2 automated system. Multilocus sequence typing analysis was carried out using seven conserved housekeeping genes. Results: The strain was resistant to penicillins, cephalosporins, carbapenems, aminoglycosides, fluoroquinolones, fosfomycin, and trimethoprim/sulfamethoxazole. The isolate was found to carry KPC-3, CTX-M-27, SHV-11, SHV-67, and TEM-1 β-lactamases. The clonal subtype of the isolate was ST147, and it possessed wzi64 and wzc38 alleles. Fifteen different point mutations (N49S, L59V, R146H, V178P, G189T, F198Y, V202L, F207Y, A217S, T222L, D223G, H235N, A280V, N304E, and S346N) were detected in the OmpK36 porin. A frame shift was observed in OmpK35 and two different point mutations (I70M and I128M) were found in the OmpK37 porin, in addition to seven mutations observed on the AcrR. Conclusions: This study demonstrated for the first time that the ST147 clone produced CTX-M-27 as well as KPC-3. In addition, new mutations were detected in the outer membrane proteins. These mutations together with the production of extended-spectrum β-lactamase and carbapenemase were found to contribute to the resistance of the ST147 clone to carbapenem and other antibiotics.

Antimicrobial resistance among GLASS pathogens in conflict and non-conflict affected settings in the Middle East: a systematic review

BACKGROUND

In spite of the evident general negative effects of armed conflict on countries' health systems and populations' health outcomes, little is known about similar impacts of conflicts on the spread of antimicrobial resistances (AMR). This review was to address this evidence gap and describe: 1. Patterns of AMR in the Middle East (ME) and resistance profiles of pathogens included in the Global AMR Surveillance System (GLASS) supported by the World Health Organization; 2. Differences in proportions of AMR isolates between conflict and non-conflict countries.

METHODS

A systematic literature review was conducted following PRISMA guidelines and searching five electronic databases. Subject heading and free text were searched for "antimicrobial resistances" and "Middle East", to identify observational studies on AMR published from January 2011 to June 2018. Data were extracted from included articles on a predefined set of variables. Percentages of AMR were analysed as median and interquartile ranges. Risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 132 articles met the inclusion criteria. Included studies showed heterogeneity in study design, laboratory methods and standards for interpretation of results, and an overall high risk of bias. Main findings were the following: 1. High proportions of carbapenem resistance in Acinetobacter spp. (median 74.2%), and both carbapenem resistance (median 8.1 and 15.4% for E. coli and K. pneumoniae respectively) and ESBL-production (median 32.3 and 27.9% for E. coli and K. pneumoniae respectively) amongst Enterobacteriaceae. S. aureus isolates showed a median methicillin resistance percentage of 45.1%, while vancomycin resistance was almost absent. A median of 50% of the strains of S. pneumoniae showed non-susceptibility to penicillin. 2. Similar trends were observed in conflict and non-conflict affected countries.

CONCLUSIONS

There is a lack of standardization in the methodological approach to AMR research in the Middle East. The proportion of antibiotic resistances among specific GLASS pathogens is high, particularly among Acinetobacter spp.

Characterization of β-lactam resistance in K. pneumoniae associated with ready-to-eat processed meat in Egypt

K. pneumoniae was known as a nosocomial infection that causes human diseases. It is considered as one of the food-borne pathogens as it causes septicemia and diarrhea in humans. This study aims to characterize K. pneumoniae strains isolated from ready to eat processed meat phenotypically and genetically. Three hundred and fifty ready to eat processed meat (Luncheon-meat) samples were collected. Forty-four (12.6%) K. pneumoniae strains were isolated and bio-typed, where the majority were identified to belong to biotype B1. K1 and K2 serotypes were detected and strains were classified as hypermucoviscous K. pneumoniae (HVKP) and classic K. pneumoniae (CKP) (26 and 18 isolates, respectively). The isolates were resistant to several classes of β–lactam antibiotics, ceftazidim and cefotaxime (95.5%), cefoxitin (93.2%), ertapenem (90.9%) and amoxicillin-clavulanic acid (86.4%). They were classified as extended spectrum β–lactamases (ESBLs), AmpC or carbapenemase-producers phenotypically. Eighteen β-lactamase genes were investigated by PCR. The most prominent genes were SHV (63.6%), TEM (52.2%), CTX-M15 (50%), AMPC (47.7%), CIT-M (45.5%) and VIM (43.2%). Co-detection of β–lactam resistance genes revealed 42 gene profiles. Twenty-four isolates had the complete efflux system (AcrAB-ToƖC). Besides, Integrons (I, II, III) were detected in 20 isolates. Molecular typing by ERIC-PCR showed high genetic diversity between isolates as 34 different patterns were identified. Overall, this study confirmed the hazards posed by the presence of multiple resistance genes in the same isolate and this should not be undervalued. Besides, the horizontal transfer of plasmid harboring resistance genes between isolates in food represents potential health risks for consumers in Egypt and so the control and inhibition plans are necessary.

Detection of several carbapenems resistant and virulence genes in classical and hyper-virulent strains of Klebsiella pneumoniae isolated from hospitalized neonates and adults in Khartoum

OBJECTIVE

Klebsiella pneumoniae (K. pneumoniae) involves both community-acquired and nosocomial infections. It is responsible for a wide variety of infections, including infections of the urinary tract, pneumonia, bacteremia, meningitis, wound infection and purulent abscesses. We constructed this study to detect several carbapenems resistant and virulence genes in classical and hyper-virulent strains of K. pneumoniae isolated from hospitalized neonates and adults in Khartoum state.

RESULTS

Seventy percent of the isolates were resistant to ceftazidime, 18(30%) to ciprofloxacin, 23(38.3%) to chloramphenicol, 24(40%) to gentamicin and 8% to imipenem, 35% were multidrug-resistant, and 7% extensively drug-resistant, all blood isolates (n = 14) were resistant to ceftazidime. entB was the most predominant virulence gene (93.3%), followed by mrkD (78.3%), kfu (60%), K2 (51.7%), magA (18.3%) and rmpA (5%). bla_OXA-48 was the most predominant carbapenem-resistant gene (68.3%), followed by bla_NDM (10%), bla_KPC (8.3%), and bla_IMP (3.3%). Eight hyper-virulent strains were positive for bla_OXA-48 and two for bla_NDM genes.

Serotyping of Klebsiella pneumoniae and Its Relation with Capsule-Associated Virulence Genes, Antimicrobial Resistance Pattern, and Clinical Infections: A Descriptive Study in Medical Practice

Objective

Klebsiella pneumoniae, one of the clinical superbugs, causes diverse infections because of its variable capsular antigens. This study focused on K. pneumoniae and aimed to assess any correlation between capsular serotype, capsule-associated virulence genes, and evaluate its resistance to conventional antibiotics in order to gain insight into any regional differences.

Materials and Methods

A total of 61 K. pneumoniae collected from various clinical specimens were confirmed genotypically. Clinical and demographic data for all patients were reviewed. All isolates were subjected to antimicrobial susceptibility tests. Capsular serotyping and capsule-associated virulence genes were studied using the molecular method.

Results

All typeable isolates were typed into K5, K20, and K54 serotypes, and among them, K54 was observed to be predominant. The most common capsule-associated virulence genes comprised uge (93.4%), ycfM (91.8%), and wabG (88.5%), while wcaG (29.5%) and rmpA (21.3%) were noted at much lower prevalence rates. The gene wcaG was significantly associated with K54 positive isolates (p = 0.001), while rmpA was associated with K20 positive isolates (p = 0.01).

Conclusion

Serotype K54 had a high frequency in isolates collected from patients with pulmonary diseases, while serotype K20 was associated with burn patients. Carbapenems and levofloxacin were the best therapeutic options for the treatment of infections with serotypes K20 and K54.

Genotypic validation of extended-spectrum β-lactamase and virulence factors in multidrug resistance Klebsiella pneumoniae in an Indian hospital

The emergence of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae has been increasing rapidly across the world. The presence of virulence factors in ESBL producers further adds to the pathogenicity and severity of infection, which often complicate empirical therapy and sometimes result in treatment failures. In the present study, 227 non-repeated clinical isolates of K. pneumoniae obtained from different clinical specimens from a tertiary care hospital in India were analyzed to detect the genes responsible for ESBL production (blaTEM, blaCTX-M, and blaSHV), virulence (fimH-1, mrkD, entB, irp-1), and capsule production (K1-K2). Phenotypically identified 72 ESBL producing K. pneumoniae isolates were further subjected to PCR based genotypic analysis but only 20 were found to have at least one of the ESBL producing genes. blaTEM was the most predominant gene (100%), followed by blaSHV (90%), and blaCTX-M (85%). Similarly, the most common virulence genes were fimH-1 (70%), entB (65%), markD (55%), irp-1 (25%), K1 (25%), and K2 (20%). REP-PCR profile separated them into five major clusters (I-V), indicating the existing heterogeneity among the isolates. The resistance profile data obtained from the present study can serve as the information base to understand the infection pattern prevailing in the hospital and for physicians to recommend suitable antibiotics for the patients.

Characterisation of virulence genes associated with pathogenicity in Klebsiella pneumoniae

Purpose

This study was undertaken to characterise the virulence factors in clinical strains of Klebsiella pneumoniae and analyse their association with various infections caused and also to determine the association between virulence factors and antimicrobial resistance profile.

Materials and Methods

A total number of 370 clinically significant, non-duplicate isolates of K. pneumoniae isolated from both hospitalised patients and patients attending clinics were included in this study. Polymerase chain reaction (PCR) was carried out for the detection of various virulence genes such as mucoviscosity-associated gene A (magA), gene associated with allantoin metabolism (allS), Klebsiella ferric iron uptake(Kfu), capsule-associated gene A (K2A), regulator of mucoid phenotype A (rmpA), enterobactin (entB), yersiniabactin (YbtS), aerobactin, Fimbrial adhesin (FimH) and uridine-diphosphate galacturonate 4-epimerase (uge). Antimicrobial susceptibility testing and PCR-based detection of beta-lactamase-encoding genes such as extended-spectrum beta-lactamases, AmpCs and carbapenemases were performed. Univariate analysis was done to find the association between virulence genes and mortality.

Results

The siderophore, entB, was present in most (90.5%) of the isolates. Of the 370 isolates, 345 carried multiple virulence genes; 15 harboured single virulence genes and 10 did not harbour any of the studied virulence genes. The most common combination of occurrence was entB and FimH. A mortality rate of 12.75% (38/298) was observed among hospitalised patients. None of the virulence genes had any significant association with mortality.

Conclusion

Pathogenic K. pneumoniae can harbour single to multiple virulence genes. Invasive infection with even a single virulence gene-harbouring K. pneumoniae can lead to poor outcomes. Both multidrug-resistant (MDR) and non-MDR K. pneumoniae can harbour a variety of virulence genes. None of the virulence genes have a significant association with mortality.

Phenotypic and Molecular Characterization of Multidrug Resistant Klebsiella pneumoniae Isolated from Different Clinical Sources in Al-Najaf Province-Iraq

BACKGROUND AND OBJECTIVE

Burns infections and urinary tract infections are the most important prevalent diseases in Asian countries, such as Iraq. Klebsiella pneumoniae is one of the most important bacteria cause this type of infections especially in hospitals. Therefore, the aim of this study was to investigate the prevalence of multi-drug resistance K. pneumoniae and extended-spectrum beta-lactamases producing K. pneumoniae isolates from inpatients with urinary tract infection and burns infections in Al-Kufa hospital in Al-Najaf province, Iraq.

MATERIALS AND METHODS

A total of 285 clinical samples were collected from in-patients infected with urinary tract infection (141 urine samples) and burns infections (144 burns swabs). Fourteen different antibiotics were used by disc diffusion method and 13 antimicrobials resistance genes were used by PCR technique.

RESULTS

A total of 43 K. pneumoniae strains were isolated. The highest resistance rate was observed for amoxicillin 25 μg and amoxicillin+clavulanic acid 20+10 μg (97.67%) while the lowest resistance rate was observed for imipenem 10 μg (9.30%). The most common resistance associated-genes were blaSHV (86.04%) and at lower prevalence were IMP (9.30%).

CONCLUSION

Klebsiella pneumoniae strains isolated from burns infections were more virulent than those isolated from urinary tract infections.

A fatal outbreak of ST11 carbapenem-resistant hypervirulent Klebsiella pneumoniae in a Chinese hospital: a molecular epidemiological study

BACKGROUND

Hypervirulent Klebsiella pneumoniae strains often cause life-threatening community-acquired infections in young and healthy hosts, but are usually sensitive to antibiotics. In this study, we investigated a fatal outbreak of ventilator-associated pneumonia caused by a new emerging hypervirulent K pneumoniae strain.

METHODS

The outbreak occurred in the integrated intensive care unit of a new branch of the Second Affiliated Hospital of Zhejiang University (Hangzhou, China). We collected 21 carbapenem-resistant K pneumoniae strains from five patients and characterised these strains for their antimicrobial susceptibility, multilocus sequence types, and genetic relatedness using VITEK-2 compact system, multilocus sequence typing, and whole genome sequencing. We selected one representative isolate from each patient to establish the virulence potential using a human neutrophil assay and Galleria mellonella model and to establish the genetic basis of their hypervirulence phenotype.

FINDINGS

All five patients had undergone surgery for multiple trauma and subsequently received mechanical ventilation. The patients were aged 53-73 years and were admitted to the intensive care unit between late February and April, 2016. They all had severe pneumonia, carbapenem-resistant K pneumoniae infections, and poor responses to antibiotic treatment and died due to severe lung infection, multiorgan failure, or septic shock. All five representative carbapenem-resistant K pneumoniae strains belonged to the ST11 type, which is the most prevalent carbapenem-resistant K pneumoniae type in China, and originated from the same clone. The strains were positive on the string test, had survival of about 80% after 1 h incubation in human neutrophils, and killed 100% of wax moth larvae (G mellonella) inoculated with 1 × 10⁶ colony-forming units of the specimens within 24 h, suggesting that they were hypervirulent K pneumoniae. Genomic analyses showed that the emergence of these ST11 carbapenem-resistant hypervirulent K pneumoniae strains was due to the acquisition of a roughly 170 kbp pLVPK-like virulence plasmid by classic ST11 carbapenem-resistant K pneumoniae strains. We also detected these strains in specimens collected in other regions of China.

INTERPRETATION

The ST11 carbapenem-resistant hypervirulent K pneumoniae strains pose a substantial threat to human health because they are simultaneously hypervirulent, multidrug resistant, and highly transmissible. Control measures should be implemented to prevent further dissemination of such organisms in the hospital setting and the community.

FUNDING

Chinese National Key Basic Research and Development Program and Collaborative Research Fund of Hong Kong Research Grant Council.

Association between Virulence Factors and Extended Spectrum Beta-Lactamase Producing Klebsiella pneumoniae Compared to Nonproducing Isolates

Klebsiella pneumoniae is considered an important opportunistic multidrug-resistant pathogen. Extended spectrum β-lactamases (ESBLs) and expression of a multitude of virulence factors may work in a harmony resulting in treatment failure. This study was undertaken to compare the virulence characteristics and genetic relatedness between ESBL and non-ESBL producing K. pneumoniae. Methods. Antibiotic sensitivity test of all isolates was determined by disc diffusion assay. Phenotypic and genotypic detection of ESBL were done. Various virulence factors and some virulence factor-associated genes were screened. Random amplified polymorphic DNA (RAPD) was employed to investigate the genetic fingerprints of ESBL from non-ESBL producing K. pneumoniae. Results. 50% of isolates were ESBL producers. A significant association was observed between ESBL production and biofilm (strong and moderate), serum resistance, and iss gene. Moreover, significant association between non-ESBL producers and hypermucoviscosity was identified. Dendogram analysis of RAPD profile classified K. pneumoniae isolates into four clusters (a, b, c, and d). Seventy-six percent of ESBL producers belonged to cluster a. In conclusion, this study suggests a correlation between ESBL production and some virulence factors. Therefore, success of treatment depends mainly on increased clinicians awareness and enhanced testing by laboratories to reduce the spread of these isolates.