Klebsiella Pneumoniae Isolates Research Articles

Isolation and Identification Klebsiella pneumoniae and use as Microbial Source for Extract Enzyme Arginine Deiminase from Respiratory Infections in Sheep at Babylon City, Iraq

Isolation and Identification Klebsiella pneumoniae and use as Microbial Source for Extract Enzyme Arginine Deiminase from Respiratory Infections in Sheep at Babylon City, Iraq

Clinical and Microbiologic Analysis of Klebsiella pneumoniae Infection: Hypermucoviscosity, Virulence Factor, Genotype, and Antimicrobial Susceptibility.

Hypervirulent Klebsiella pneumoniae (KP) is defined according to hypermucoviscosity or various virulence factors and is clinically associated with community-acquired liver abscess (CLA). In this study, we investigated the clinical and microbiological characteristics of KP and significant factors associated with hypervirulence. The clinical characteristics, antimicrobial susceptibility, hypermucoviscosity, serotypes, hypervirulence-related genes, and biofilm formation of 414 KP isolates collected from the Keimyung University Dongsan Hospital between December 2013 and November 2015 were analyzed according to CLA. Significant risk factors for hypervirulent KP (HvKP) associated with CLA were investigated using logistic regression analysis. Notably, 155 (37.4%) isolates were hypermucoviscous, and 170 (41.1%) harbored aerobactin. CLA was present in 34 cases (8.2%). Epidemiology and treatment outcomes did not differ significantly between the CLA and non-CLA groups. The CLA group had significantly higher antibiotic susceptibility, K1/K2, rmpA, magA, allS, kfu, iutA, string test-positive result, and biofilm mass. Multivariate logistic regression revealed rmpA (OR, 5.67; 95% CI, 2.09-15.33; p = 0.001), magA (OR, 2.34; 95% CI, 1.01-5.40; p = 0.047), and biofilm mass >0.80 (OR, 2.13; 95% CI, 1.00-4.56; p = 0.050) as significant risk factors for CLA. rmpA was identified as the most significant risk factor for CLA among KP strains, implying that it is an important factor associated with HvKP.

Enhancing bactericidal activities of ciprofloxacin by targeting the trans-translation system that is involved in stress responses in Klebsiella pneumoniae.

Although the trans-translation system is a promising target for antcibiotic development, its antibacterial mechanism in Klebsiella pneumoniae (KP) is unclear. Considering that tmRNA was the core component of trans-translation, this study firstly investigated phenotypic changes caused by various environmental stresses in KP lacking trans-translation activities (tmRNA-deleted), and then aimed to evaluate antibacterial activities of the trans-translation-targeting antibiotic combination (tobramycin/ciprofloxacin) in clinical KP isolates based on inhibition activities of aminoglycosides against trans-translation. We found that the tmRNA-deleted strain P4325/ΔssrA was significantly more susceptible than the wild-type KP strain P4325 under environments with hypertonicity (0.5 and 1M NaCl), hydrogen peroxide (40mM), and UV irradiation. No significant differences in biofilm formation and survivals under human serum were observed between P4325/ΔssrA and P4325. tmRNA deletion caused twofold lower MIC values for aminoglycosides. As for the membrane permeability, tmRNA deletion increased ethidium bromide (EtBr) uptake of KP in the presence or absence of verapamil and carbonyl cyanide-m-chlorophenylhydrazone (CCCP), decreased EtBr uptake in presence of reserpine in P4325/ΔssrA, and reduced EtBr efflux in P4325/ΔssrA in the presence of CCCP. The time-kill curve and in vitro experiments revealed significant bactericidal activities of the tmRNA-targeting aminoglycoside-based antibiotic combination (tobramycin/ciprofloxacin). Thus, the corresponding tmRNA-targeting antibiotic combinations (aminoglycoside-based) might be effective and promising treatment options against multi-drug resistant KP.

In-depth characterization of multidrug-resistant NDM-1 and KPC-3 co-producing Klebsiella pneumoniae bloodstream isolates from Italian hospital patients.

Bloodstream infection (BSI) caused by carbapenem-resistant Klebsiella pneumoniae (KP) poses significant challenges, particularly when the infecting isolate carries multiple antimicrobial resistance (AMR) genes/determinants. This study, employing short- and long-read whole-genome sequencing, characterizes six New Delhi metallo-β-lactamase (NDM) 1 and KP carbapenemase (KPC) 3 co-producing KP isolates, the largest cohort investigated in Europe to date. Five [sequence type (ST) 512] and one (ST11) isolates were recovered from patients who developed BSI from February to August 2022 or February 2023 at two different hospitals in Rome, Italy. Phylogenetic analysis revealed two distinct clusters among ST512 isolates and a separate cluster for the ST11 isolate. Beyond blaNDM-1 and blaKPC-3, various AMR genes, indicative of a multidrug resistance phenotype, including colistin resistance, were found. Each cluster-representative ST512 isolate harbored a blaNDM-1 plasmid (IncC) and a blaKPC-3 plasmid [IncFIB(pQil)/IncFII(K)], while the ST11 isolate harbored a blaNDM-1 plasmid [IncFII(pKPX1)] and a blaKPC-3 plasmid [IncFIB(K)/IncFII(K)]. The blaNDM-1 plasmids carried genes conferring resistance to clinically relevant antimicrobial agents, and the aminoglycoside resistance gene aac(6')-Ib was found on different plasmids. Colistin resistance-associated mgrB/pmrB gene mutations were present in all isolates, and the yersiniabactin-encoding ybt gene was unique to the ST11 isolate. In conclusion, our findings provide insights into the genomic context of blaNDM-1/blaKPC-3 carbapenemase-producing KP isolates.IMPORTANCEThis study underscores the critical role of genomic surveillance as a proactive measure to restrict the spread of carbapenemase-producing KP isolates, especially when key antimicrobial resistance genes, such as blaNDM-1/blaKPC-3, are plasmid borne. In-depth characterization of these isolates may help identify plasmid similarities contributing to their intra-hospital/inter-hospital adaptation and transmission. Despite the lack of data on patient movements, it is possible that carbapenem-resistant isolates were selected to co-produce KP carbapenemase and New Delhi metallo-β-lactamase via plasmid acquisition. Studies employing long-read whole-genome sequencing should be encouraged to address the emergence of KP clones with converging phenotypes of virulence and resistance to last-resort antimicrobial agents.

Two novel phages, Klebsiella phage GADU21 and Escherichia phage GADU22, from the urine samples of patients with urinary tract infection.

Phages are found in a wide variety of places where bacteria exist including body fluids. The aim of the present study was to isolate phages from the urine samples of patients with urinary tract infection. The 10 urine samples were cultured to isolate bacteria and also used as phage sources against the isolated bacteria. From 10 urine samples with positive cultures, 3 phages were isolated (33%) and two of them were further studied. The Klebsiella phage GADU21 and Escherichia phage GADU22 phages infected Klebsiella pneumonia and Escherichia coli, respectively. Among the tested 14 species for host range analysis, the Klebsiella phage GADU21 was able to infect two species which are Klebsiella pneumonia and Proteus mirabilis, and Escherichia phage GADU22 was able to infect four species which are Shigella flexneri, Shigella sonnei and Escherichia coli. Among different isolates of the indicator bacteria for each phage, GADU21 infected half of the tested 20 Klebsiella pneumonia isolates while GADU22 infected 85% of the tested 20 E. coli isolates. The genome sizes and GC ratios were 75,968bp and 44.4%, and 168,023bp and 35.3% for GADU21 and GADU22, respectively. GADU21 and GADU22 were both lytic and had no antibiotic resistance and virulence genes. GADU21 was homologue with Klebsiella phage vB_KpP_FBKp27 but only 88% of the genome was covered by this phage. The non-covered parts of the GADU21 genome included genes for tail-fiber-proteins and HNH-endonuclease. GADU22 had 94.8% homology with Escherichia phage vB_Eco_OMNI12 and had genes for immunity proteins. Phylogenetic analysis showed GADU21 and GADU22 were members of Schitoviridae family and Efbeekayvirus genus and Straboviridae family and Tevenvirinae genus, respectively. VIRIDIC analysis classified these phages in new species clusters. Our study demonstrated the possibility to use infected body fluids as phage sources to isolate novel phages. GADU21 is the first reported Klebsiella phage isolated from human body fluid. The absence of virulence and antibiotic resistance genes in their genomes makes the phages a potential therapeutic tool against infections.

Molecular characterisation of pathogens isolated from egg samples

ceA on the biochemical analysis of this study, which is similar to a battery of biochemical tests including methyl red, Voges-Proskauer, indole and citrate, the organisms were determined to be Klebsiella. In the present study, the highest resistance rate was observed for inoflavuxin (50%) and ceftazidimine (80%), which is similar to the highest resistance rate for cefotaxime (85%) and ceftazidime (68%), with the MIC ranging from 32 to 256 mg/l. The Pseudomonas and Klebsiella plasmid isolation in the present study was found to have a molecular weight of 2.6 kb and 2.7 kb, which is similar to most isolates harboring multiple plasmids ranging in size from about 2 kb to over 150 kb included. Seventy-nine isolates contained plasmids larger than 50 kb, and some contained multiple large plasmids. In the present study, the molecular weight of Pseudomonas and Klebsiella was found to be 356 base pairs and 359 base pairs, respectively, which is similar to that of the 85 clinical isolates of Klebsiella pneumonia screened by PCR amplification of the antiseptic resistance genes qacE1 and ceA.

EMERGENCE OF CEFTAZIDIME-AVIBACTAM RESISTANCE IN ENTERO-BACTERALES AND PSEUDOMONAS AERUGINOSA

Objective: The objective of this study is to determine the emergence of resistance to Ceftazidime-Avibactam (CAZ-AVI) by Enterobacterales and Pseudomonas aeruginosa in clinical isolates. Material and Methods: In this cross-sectional study (6-months) March-August 2022 Carbapenem resistant Enterobacterales were tested for Ceftazidime-Avibactam (30/20 µg, Oxoid Pvt Ltd) using Disk diffusion technique and enzymes were identified in resistant strains by Carbapenem Inactivation Method (mCIM, eCIM) as per CLSI M100 Guidelines 2022. Results: CAZ-AVI effectiveness has greatly decreased among Enterobacterales and P. aeruginosa isolates in recent past. Antimicrobial susceptibility testing results were interpreted using CLSI M100 document. Resistance against CAZ-AVI in Enterobacterales was found to be 80.8 % in E. coli and 72.1% in Klebsiella pneumonia isolates. This higher emergence is associated with CRE isolates majorly comprising MBLs in our country. Moreover, it has been observed that Metallo- β-lactamases mediated enzyme resistance is one of the major resistance patterns followed by serine carbapenemases. Conclusion: The high frequency of resistance 77% was observed against CAZ-AVI in CRE and in CRPA, the resistance is 80.1% respectively. In our country this tremendously increase in CAZ-AVI resistance is attributed to the existence of NDM in the region. Keywords: Carbapenem Resistant Enterobacterales (CRE), Metallo beta lactamases (MBLs), Carbapenem Resistant Pseudomonas aeruginosa (CRPA) Ceftazidime-Avibactam (CAZ-AVI), Modified Carbapenem Inactivation Method (mCIM), EDTA-modified Carbapenem Inactivation Method(eCIM), Multiple Drug Resistance (MDR)

In vitro activity of novel apramycin-dextran nanoparticles and free apramycin against selected Dutch and Pakistani Klebsiella pneumonia isolates

Klebsiella pneumoniae are bacteria associated with respiratory tract infections and are increasingly becoming resistant to antibiotics, including carbapenems. Apramycin is a veterinary antibiotic that may have the potential to be re-purposed for use in human health, for example, for the treatment of respiratory tract infections after coupling to inhalable nanoparticles. In the present study, the antibiotic apramycin was formulated with single chain polymeric nanoparticles and tested in free and formulated forms against a set of 13 Klebsiella pneumoniae isolates (from the Netherlands and Pakistan) expressing different aminoglycoside resistance phenotypes. Minimum Inhibitory Concentration, Time Kill Kinetics and biofilm experiments were performed providing evidence for the potential efficacy of apramycin and apramycin-based nanomedicines for the treatment of human Klebsiella pneumonia infections.

Anti-microbial and anti-cancer efficacy of acetone extract of Rosa chinensis against resistant strain and lung cancer cell line

BackgroundScreening of herbal plants for various therapeutic properties is the hour as it shows promising activity. Scientific evidence of the pharmacological activity of the plant strengthens the traditional application of plants.MethodsRose flowers (Rosa chinensis) were procured and grounded into a coarse powder. The DNA was isolated from rose flower and molecular identification was performed by rbcL-BF and rbcL-724R primers. Antibacterial activity was evaluated by using disc and agar diffusion methods and the anti-cancer effect of the rose flower extract (RE) was examined using MTT assay in lung cancer cell line. The mechanism of cell death induced by RE was qualitatively measured using Acridine orange/Ethidium bromide staining and Hoechst staining. GC-MS analysis was performed using GC-MS-5975C.ResultThe RE showed potent antimicrobial activity against various ATCC cultures. The rose extract strongly inhibits the growth of ESBL resistant organism along with inhibition of biofilm formation in the ESBL resistant organism. The extract caused apoptotic and necrotic cell death in lung cancer cells. GC-MS analysis demonstrated the presence of several biologically active compounds such as Clindamycin, Phytol, Octanoic acid, and Stigmasterol which might be the reason for the therapeutic properties of the plant.ConclusionThis study shows the antimicrobial and biofilm inhibition activity against the clinical isolates of Klebsiella pneumonia. The study shows the cytotoxic and apoptotic activity in A549 cancer cell line. Thus, the plant may act as a potent antimicrobial drug against resistant strains.

EVALUATION OF QUORUM SENSING SIGNALS OF STRONG BIOFILM PRODUCING BACTERIA VIA LC-MSMS, HPLC AND BIOSENSORS

This study aimed to show presence of Quorum Sensing (QS) signals of Gram-negative and Gram-positive biofilm producing bacteria isolated from real dairy process lines. Defining the profile and chemical composition of QS-signals is an important factor in control of microbial resistance and biofilm production. We especially focused on unusual behaviour of Gram-positive and Gram-negative isolates. Long-chain acyl-homoserine lactones (AHLs) signals (C14-HSL, C16-HSL and C18-HSL) and DFD (4,5-dihidroksi-2,3-pentanedione)-AI-2 signals of the isolates were studied by High-performance liquid chromatography (HPLC) and Liquid Chromatography with tandem mass spectrometry (LC-MSMS) methods. All Gram-positive isolates were defined as AHL-producers. All Gram-negative isolates, formerly defined as non-AHL producers by both biosensors and HPLC methods, were identified as AHL-producers. DFD signal was only detected from Gram-negative Klebsiella pneumonia, Enterobacter cloacae and Klebsiella oxytoca isolates. The results demonstrated that the QS-system is a complex system and biosensor microorganism may not be the best method for QS-signal identification. The results also provided new insights in defining the profile and chemical composition of QS-signals importance for interrupting the chemical communication completely to reduce biofilm formation and prevent resistance gain of microorganisms.

Detection of Biofilm Formation Among the Clinical Isolates of Klebsiella pneumoniae: Phenotypic and Genotypic Methods

Infections caused by biofilm-embedded pathogens decrease the efficacy of traditional treatments and increase antibiotic tolerance. Most of the human bacterial infections are biofilm-associated. Therefore, this study aimed to detect the biofilm formation among the clinical isolates of Klebsiella pneumonia collected from different hospitals in Wasit province-Iraq by phenotypic and genotypic methods. 525 clinical samples were used to isolate 77 K. pneumoniae strains from clinical specimens for five months. They were identified by microbiological method as K. pneumoniae. The microtiter plate method is used to detect the biofilm formation. Results showed that out of 77 K. pneumonia isolates, 76 (98.7%) isolates were biofilm producers with three different categories; 12 (15.6%) were weak-biofilm producers, while other isolates 63 (81.8%) and 1 (1.3%) were moderate and vigorous producers, respectively. However, 1 (1.3%) isolates were identified as nonbiofilm producers. Amplification of genes by multiplex PCR technique was done for 77 isolates of K. pneumonia to detect biofilm production genes, mrkD and FimH. Results showed that out of 77 isolates, there were 74 isolates (94.8%) positive to mrkD and 33 isolates (42.8%) to fimH. Keywords: K. pneumonia; Microtiter plate method; mrkD; fimH; Iraq.

Antimicrobial resistance and virulence of carbapenem-resistant <i>Klebsiella pneumoniae</i> strains isolated from children in intensive care and surgical units

Introduction. Infections associated with carbapenem-resistant (Carba-R) Klebsiella pneumoniae (KP) are a serious public health problem because they lead to an increase in hospital stays, treatment costs, and an increase in patient morbidity and mortality.
 Aim to characterize antimicrobial resistance, virulence factors and genotypes of Carba-R KP strains isolated from patients in intensive care and surgical units.
 Materials and methods. In total, 455 KP strains that were resistant to meropenem and/or imipenem, or susceptible to meropenem and/or imipenem at increased exposure were collected in 20182020. For further analysis, total 90 KP strains isolated from clinically significant sites blood/сerebrospinal fluid/urine/lower respiratory tract/wounds/abdominal cavity of patients in intensive care and surgical units were selected. Antibiotic susceptibility was determined using the broth microdilution method. Carbapenemase genes were detected by real-time PCR. The virulence genes and K1/K2 capsular serotypes were determined by multiplex PCR. Sequence types (ST) were determined using multilocus sequence typing.
 Results. Most of the selected isolates (97%) were recognized as extensively drug-resistant pathogens, three isolates were classified as multidrug-resistant pathogens. The major determinant of carbapenem resistance was blaOXA-48-like (53%), blaNDM-group was detected in 13% strains, a combination of blaNDM-group and blaOXA-48-like genes was found in 31% isolates. Two isolates harbored blaKPC-group. Most of the isolates had the virulence genes entB (100%), mrkD (99%), and ybtS (78%). The iutA gene was found in 16% strains. Four isolates had kfu gene and four strains carried rmpA gene. The K2 capsule type was determined in 13% isolates. Four ST dominated in the studied population: ST395 (26%), ST2975 (19%), ST198 (12%) and ST307 (11%).
 Conclusion. Carba-R KP isolates had a high level of resistance not only to carbapenems, but also to antibiotics of other classes. Carbapenem resistance was mainly associated with OXA-48 carbapenemase. The entB, mrkD and ybtS genes were the main determinants of virulence. The epidemically successful clones CG395 and CG307 were the predominant genetic lines. Resistance to antimicrobials was combined with the presence of various virulence factors. The data obtained are important for the epidemiological surveillance of the spread of KP and have important clinical implications.

Design, synthesis, and unraveling the antibacterial and antibiofilm potential of 2-azidobenzothiazoles: insights from a comprehensive in vitro study.

The present study reports the synthesis of 2-azidobenzothiazoles from substituted 2-aminobenzothiazoles using sodium nitrite and sodium azide under mild conditions. All the synthesized compounds were examined for their antibacterial activity against Gram (+) bacteria, Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 51299), Bacillus cereus (ATCC 10876) and Gram (-) bacteria, Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 10145), Klebsiella pneumonia (ATCC BAA-2146)and clinical isolates of Gram (+) Methicillin Resistant S. aureus (MRSA) and Multi Drug Resistant E. coli. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values by broth dilution method revealed that compound 2d exhibited significant antibacterial potential against E. faecalis and S. aureus with MIC of 8μg/mL, while other synthesized compounds had only moderate effects against all the tested species. The compound significantly inhibited the biofilm formation of the bacterial strains below its MIC. The selective cytotoxicity of Compound 2d towards bacterial cells was evidenced on extended exposure of Human Embryonic Kidney-293 cell line to higher concentrations of the compound. Hence, the present study confirmed that compound 2d can be a potential drug candidate for future development as an antibacterial drug.

Microtopographic superhydrophobic polymer surface to prevent urinary tract infections causing nosocomial drug-resistant bacterial adhesion

Catheter-associated urinary tract infections (CAUTIs) are one of the most prevalent forms of healthcare-associated infections worldwide. Recurrent episodes of infections and development of antibiotic resistance/tolerance among biofilm-forming bacteria are well documented. We developed a simple method of making superhydrophobic micro-structured antibacterial polymer surfaces for coating-free catheters. A two-step fabrication approach was used to turn the hydrophobic polydimethylsiloxane (PDMS) into superhydrophobic surfaces. The nanosecond pulsed Nd:YAG laser was used to fabricate two types of structures (holes and grooves) on a steel mold. The soft-molding technique was adopted to replicate these structures on PDMS films. The pillar structured PDMS surface exhibited a water droplet contact angle (WDCA) of 169○ ± 3° with a low sliding angle of 12○, whereas the grooved surface had 142○ ± 5° contact angle. Moreover, the Luria Broth which is media for bacterial growth shows contact angle of 141○ ± 2° and 120○ ± 3°, respectively. Theoretically, the micro-pillar structures with selected dimensions could sustain the Cassie–Baxter state. The crystal violet binding assay was used to assess the anti-biofilm activity of structured surfaces (grooved and pillared) against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as well as clinical isolates of Klebsiella pneumonia (K. pneumoniae), E. coli, and S. aureus. Furthermore, the attachment and interaction of bacteria with surfaces were investigated through filed emission scanning electronic microscope (FE-SEM) and confocal microscopy. Overall, the pillar-structured surface reduces the average bacterial attachment more efficiently than a grooved surface (>80% vs. >50% reduction) compared to a plain PDMS surface due to its higher water-repellent property. This work will give new insights into the development of coating-free, long-lasting antibacterial surfaces for polymeric medical devices.

Characterization of multidrug and heavy metal resistance of carbapenemases producing Klebsiella pneumoniae from poultry samples in Bangladesh.

Resistance to multiple drugs in Klebsiella pneumoniae (KPN) is an important issue in human and animal medicine. KPN phenotypic and genotypic aspects in poultry samples have not been comprehensively explored in Bangladesh. This research focused on the prevalence of antibiotic resistance and the characterization of KPN in Bangladeshi poultry isolates using both phenotypic and genotypic approaches. A total of 32 poultry samples were randomly obtained from a commercial poultry farm in Narsingdi, Bangladesh, and 43.90% (18/41) of the isolates were confirmed to be KPN, whereas all isolates were biofilm producers. The antibiotic sensitivity test revealed the most remarkable (100%) antibiotic resistance level against Ampicillin, Doxycycline and Tetracycline while remaining susceptible to Doripenem, Meropenem, Cefoxitin and Polymyxin B. Resistance to Nalidixic acid, Nitrofurantoin, Trimethoprim, Levofloxacin, Ciprofloxacin, Cefuroxime and Chloramphenicol ranges from 18% to 70%. Minimum inhibitory concentrations for carbapenem-resistant KPN ranged from 128 to 512mg/mL for Meropenem, Imipenem, Gentamycin and Ciprofloxacin, respectively. [Correction added on 15 June 2023, after first online publication: 512 g/mL was corrected to 512 mg/mL in the preceding sentence]. Carbapenemase-producing KPN isolates harboured a single or multiple β-lactamase genes, blaSIM-1 , blaIMP-4 and blaOXA-48 as well as one ESBL gene (blaTEM ) and plasmid-mediated quinolone resistance gene (qnrB). Furthermore, Cr and Co outperformed Cu and Zn in antibacterial effectiveness. The results of this investigation showed that the high prevalence of multidrug-resistant pathogenic KPN in our chosen geographic location had displayed sensitivity to FOX/PB/Cr/Co, which might be regarded as an alternate treatment to reduce pressure of use on carbapenems.

Coexistence Of Blaoxa-48, Blavim, And Blashv Genes In Klebsiella Pneumoniae And Escherichia Coli Isolated From Urinary Tract Infections: Microbiological And Epidemiological Analysis.

To investigate antimicrobial resistance mechanisms of isolated bacterialstrains, and their correlation with virulence profile. The cross-sectional study was conducted in January 2020 at outpatient health centres in Kafrelsheikh Governorate of Egypt, and comprised urine samples from patients regardless of age and gender. Midstream samples were collected into sterile swaps which were kept in ice-cooled boxes until transported to the laboratory within 5h. Antimicrobial resistance profile of the isolated Enterobacteriaceae was done using Kirby-Bauer disk diffusion method and was confirmed withVitek compact 2. The phenotypic of carbapenemases and extended-spectrum beta lactamase was determined, and polymerase chain reaction was used, as appropriate. Data was analysed using SPSS 20. Of the 199 patients, 101(50.7%) were females and 98(49.3%) were males. The majority 73(36.6%) were aged 30-50 years. Urinary tract infection was found in 68(34.2%) patients. In 28(41.2%) of these patients, there were 32 isolates of Enterobacterales; 21(65.62%) Klebsiella pneumoniae, 7(21.87%) Escherichia coli and 4(12.5%) Enterobacter cloacae. Of the 28(41.2%) patients, 24(85.7%) were infected with a single strain; 17(70.8%) Klebsiella pneumoniae, 4(16.7%) Escherichia coli and 3(12.5%) Enterobacter cloacae. In 3(10.7%) cases, there was co-infection with Escherichia coli and Klebsiella pneumoniae, and 1(3.6%)sample had mixed infection with Klebsiella pneumoniae and Enterobacter cloacae. The other 40(58.8%) patients had other causative agents. Housewives, agricultural workers and those aged >50 years had a higher risk of urinary tract infections(p<0.05) Among Klebsiella pneumonia isolates, 6(28.5%) possessed carbapenemase-related genes and 4(19.1%) extended-spectrum beta lactamase-related genes. The carbapenemase related genes were bla-Verona integron-encoded metallo beta lactamase 6(100%) bla-New Delhi metallo beta lactamase-1 4(66.6%) and bla-oxacillinase-48 2(33.3%). The 4(19.1%) cases of extended-spectrum beta lactamase related genes had bla-temoneira gene 3(75%) and bla-sulfhydryl variable gene 4(100%). In Escherichia coli isolates, bla-oxacillinase-48 and bla-Cefotaximase genes were observed in 2(28.5%) cases.Virulence genes uridine diphosphate glucose 4-epimerase, fimbrial adhesion and mannose-resistance adhesin of Klebsiella spp genes in Klebsiella pneumoniae isolates were positive in in 16(76.2%), 14(66.7%) and 10(47.6%) cases, respectively. All 21(100%) isolates of Klebsiella pneumoniae were negative for mucoviscosity-associated gene A. There was evidence of the coexistence of bla- oxacillinase-48, bla-Verona integron-encoded metallo beta lactamase and bla-sulfhydryl variable genes in Klebsiella pneumoniae and Escherichia coli isolates from mixed urinary tract infection samples.

Antibiotic resistance of Klebsiella pneumoniae and practical significance for veterinary medicine

For successful pharmacotherapy of animals, species identification of pathogens, analysis of antibiograms and interpretation of the results, and laboratory monitoring of the mechanisms of antibiotic resistance are important. This is necessary for veterinarians to rationally select antibacterial drugs and predict their clinical effectiveness. In veterinary clinics, antimicrobial therapy requires review of therapeutic efficacy more often than other treatments.Klebsiella are widely distributed in nature. These microorganisms are often etiological factors in septicemia in cattle, birds, horses, pigs, as well as in the development of infectious diarrhea in young farm animals.The purpose of the study is to study the antimicrobial resistance of Klebsiella pneumoniae isolated from dogs and its practical significance for veterinary medicine.Materials and methods. The microorganism K. pneumoniae was isolated from wound contents in a dachshund dog. The dog was observed in the intensive care unit in the veterinary clinic.The sensitivity to antibacterial drugs was assessed by the method of diffusion of antibiotics into agar.Research results. In the period from 2021 to 2022, a total of 100 isolates were isolated from dogs with purulentinflammatory processes, among which 18% are gram-negative and 82% are gram-positive microorganisms, and the case of Klebsiella pneumoniae isolation is 1%.The isolates of Klebsiella pneumonia were characterized by resistance to aminoglycosides (gentamicin, tobramycin, amikacin), III generation cephalosporins (cefotaxime, ceftriaxone, ceftazidime), IV cephalosporins (cefepime), penicillins (Amoxicillin/clavulanic acid), carbapenems (imipenem, meropenem, doripenem, ertapenem). ), fluoroquinolones (ciprofloxacin, ofloxacin, levofloxacin, moxifloxacin), aminoglycosides (gentamicin, amikacin, tobramycin) and a number of other antimicrobial drugs (sulfamethoxazole trimethoprim). Klebsiella was highly sensitive only to fosfomycin.When analyzing this antibiogram of Klebsiella pneumoniae, it is necessary to conduct additional laboratory studies in order to establish the minimum inhibitory concentrations of antibiotics and to study the mechanisms of resistance.Conclusion. Among strains of Klebsiella pneumoniae isolated from wound exudate in dogs, there is a spread of resistance to most antibiotics, as well as an increase in resistance to cephalosporins and carbapenems. It is necessary to carry out laboratory control of antibiotic resistance for further rational use of antibacterial drugs.

Virulence analysis and antibiotic resistance of Klebsiella pneumoniae isolates from hospitalised patients in Poland

Klebsiella pneumoniae (KP) is a nosocomial pathogen causing difficult-to-treat infections. The presence of virulence genes and antibiotic resistance of 109 KP isolates from hospitalized patients were investigated. Among them, 68.8% were multi-drug resistant (MDR) and 59.6% produced extended‐spectrum beta‐lactamases (ESBLs). Metallo-β-lactamases (MBLs) were produced by 22% of isolates (mainly from anus), including 16.5% of isolates producing New Delhi metallo-β-lactamase (NDM-1). The genes encoding adhesins (fimH—91.7%, mrkD—96.3%), enterobactin (entB—100%) and yersiniabactin (irp-1—88%) were frequently identified. The genes encoding salmochelin (iroD—9.2%, iroN—7.3%) and colibactin (clbA, clbB—0.9%) were identified rarely. Iron acquisition system-related kfu gene and wcaG gene involved in capsule production were identified in 6.4% and 11% of isolates, respectively. The rmpA gene associated with hypermucoviscosity was present in 6.4% of isolates. In 19.2% of isolates magA gene was detected, specific for K1 capsule serotype, while 22.9% of isolates showed K2 capsule serotype. The rmpA, iroD or iroN genes being diagnostic biomarkers for hypervirulent KP (hvKP) were detected in 16.5% of isolates. We found that 55.5% of hvKP were MDR and produced ESBLs, thus hospital KP isolates pose a serious threat to the healthcare system.

Susceptibility Profile of Nitrofurantoin and Fosfomycin among Carbapenem-resistant Enterobacteriaceae Isolates in UTI from a Tertiary Care Hospital

UTI is one of the most common infections requiring antibiotic treatment and hospitalization. The rising trend in multidrug resistance to commonly used antibiotics has reduced the therapeutic options for treating these infections. Reexploring older antibiotics like nitrofurantoin and fosfomycin provide treatment options and help combat resistance. This prospective study was conducted in the Department of Microbiology, SRM Medical College Hospital and Research Center, from July 2021 to February 2022. The study included only clean catch midstream urine isolates of Escherichia coli and Klebsiella pneumonia from hospitalized patients and outpatients. Standard microbiological procedures were used to process the urine samples. Direct gram stain and conventional biochemical reactions were performed to identify the isolates. The antimicrobial susceptibility testing was carried out by the Kirby Bauer disk diffusion method and Minimum Inhibitory Concentration by E- test gradient method for fosfomycin. MIC for nitrofurantoin was determined by Micro Broth Well Dilution according to CLSI guidelines 2021. Among 150 urine samples, Escherichia coli 107 (71.3%) was higher than Klebsiella pneumonia 43 (29%). Carbapenemase production was seen in 58 (63.04%) isolates by the Kirby Bauer disc diffusion method. Among the 58 positive carbapenemase producers, E. coli was found to be 33 (56.8%), and Klebsiella pneumonia was 25 (43.1%). Fosfomycin susceptibility rates by E test were reported to be high in Escherichia coli, ranging from 0.5-1mg/L. Klebsiella pneumonia was less susceptible to fosfomycin ranging from 16-32mg/L. Only 7(21%) isolates of Escherichia coli showed MIC of 1-4µg/ml to nitrofurantoin by broth microdilution. 21 (63.63%) isolates of Escherichia coli and 11(44%) isolates of Klebsiella pneumonia were reported to have an intermediate category with MIC of 8-32µg/mL. A higher MIC of 64- &gt; 256µg/ml was shown by 5 (15.15%) isolates of Escherichia coli and 14 (56%) isolates of Klebsiella pneumonia. Older medications may resurface as useful therapeutic choices as resistance to current treatment options grow.

Design, synthesis, and antibacterial activity of a new series of ciprofloxacin-thiadiazole hybrid

This study synthesized novel ciprofloxacin analogs bearing the 2-amino-1,3,4-thiadiazole ring, including tryptophan and different sulfonamides, to act as antimicrobial agents. Then, the activities of the synthesized hybrids were screened against 18 tested bacterial isolates from 4 standard strains (Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 25,923, Acinetobacter baumannii ATCC 19,606, and Pseudomonas aeruginosa PAO1) and 14 clinical strains (2 Enterobacter cloacae and 12 Klebsiella pneumonia isolates). Investigations revealed that compound 2 showed better antimicrobial activities among the synthesized compounds than the standard drug, ciprofloxacin, demonstrated by its lower MIC and MBC values. We also notably observed that compared to ciprofloxacin, compound 2 maintained its activity for a longer time without inducing resistance in the tested bacterium. Hence, we conducted a time-to-kill assay and compared the results with its parent drug, followed by a molecular modeling simulation study through the docking of compound 2 into E. coli DNA gyrase enzyme active site to elucidate its binding modes to the receptor. Then, we compared these results with ciprofloxacin and calculated the physicochemical descriptors, ADME parameters, pharmacokinetic properties, and drug-like nature profile of compound 2 as the most potent were also calculated. Based on our findings, we conclude that with further modifications of compound 2, the design of a new and optimized fluoroquinolone generation should be possible.