Klebsiella Pnuemoniae Research Articles

Multi Drug Resistant (MDR) Klebsiella pnuemoniae Isolated from Different Sources

Background: Multidrug-resistant pathogens are a significant cause of morbidity globally. The recent rise in resistant bacterial strains is largely attributed to the extensive use of antibiotics in human and animal treatment. In recent years, there has been a notable increase in drug-resistant Klebsiella pneumoniae strains, posing a major challenge for clinicians worldwide. Methods: In the current study, 121 samples were obtained from bovine mastitis milk and faeces, dairy cattle farm premises, chicken cloacal swabs, poultry farm litter and water. The samples were processed for the isolation and identification of Klebsiella species. Klebsiella isolates were identified by cultural, morphological and biochemical characteristics and were subsequently confirmed by PCR assays that targeted species-specific genes. The isolates were subjected to in vitro antibiotic sensitivity test. The DNA from all the isolates was extracted and subjected to PCR to identify the presence of 10 different Antibiotic Resistance Genes (ARG) using published primers. The ARGs targeted were blaTEM, blaSHV, blaOXA, blaIMP, DHAM, MOXM, tetA, tetB, sul1 and aadA. Result: Out of 121 samples, twenty-six (21.4%) samples were identified as Klebsiella pnuemoniae isolates. The occurence of Klebsiella pnuemoniae in samples from different sources was- 3/33 (09%) from mastitis milk, 8/27 (29.6%) from faecal samples and 04/14 (28.5%) from environmental samples collected from dairy farms. Similarly, Klebsiella pnuemoniae prevalence was recorded to be 6/33 (18.1%) in cloacal swabs and 5/14 (35.7%) from environmental samples collected from poultry farms. On in vitro antibiotic sensitivity test, all the Klebsiella pneumoniae isolates were found to be resistant to penicillin, amoxicillin, cefuroxime and ampicillin/ sulbactam (100% each), followed by cefalexin (65.3%), streptomycin (53.8%), tetracycline (38.4%), imipenum and co-trimoxazole (34.6% each), ofloxacin (30.7%), norfloxacin (27%), ceftriaxone (23%), amikacin (15.38%) and gentamicin (11.5%). All the K. pneumoniae isolates were found to be Multi Drug Resistant (MDR). Out of 26 isolates, 25 (96%) were positive for Sul1, 22 (84.6%) for blaTEM, 19 (73%) for blaSHV, 19 (3%) for tetA, 16 (61.5%) for aadA, 10 (38.4%) for OXA, 9 (34.6%) for tetB and 2 (7.6%) for DHAM and MOXM each. None of the isolates harboured blaIMP gene.

Genomic insights into prevalence of virulence and multi drug resistance genes in milk borne Klebsiella pnuemoniae: Face of emerging resistance to last resort antibiotics

Spread of hypervirulent and multi-drug resistant Klebsiella pneumoniae in raw milk is public health concern due to its potential impact on food safety and public health. Therefore, this study investigated antibiotic susceptibility test (AST), antibiotic resistance genes (ARGs), mutations conferring ARGs, virulence factor and plasmid replicons to check prevalence of fosfomycin resistant MDR K. pneumoniae isolated from raw milk samples collected from Saurashtra region of Gujarat, India. K. pneumoniae isolated from raw milk and subjected to disk diffusion assay. From that, MDR along with fosfomycin resistant isolates were analysed for multi locus sequence typing, presence of ARGs, mutations conferring resistance, virulence factors and plasmid replicon types by using its whole genome sequence. Results shows that, among 32 K. pneumoniae, 8 were phenotypically resistant to fosfomycin. As per WGS analysis, 8 MDR isolates were assigned into different sequence types such as ST3321, ST37, ST2715, ST1087, ST3157, ST299 and ST29. Among that, ST37 is well recognized MDR high risk clone reported worldwide and first time reported from raw milk of Saurashtra region of Gujarat, India. ARGs responsible for resistance to fosfomycin (fosA) were found in all 8 isolates. Other ARGs such as blaSHV, kdeA, OqxA, OqxB, dfrA1, sul1, qnrB4, aadA2 and ere(A) were also detected. High diversity of virulence factors was also identified by detection of genes encoding virulence factors related to iron uptake such as entE, fepD, entA, entB, Irp2, fepG, ybtU, ybtP, fepC, ybtA, ybtE, fepB, ybtS, fyuA, ybtQ, ybtT, ybtX, Irp1, adherence such as yagZ/ecpA, yagV/ecpE, yagX/ecpC, yagV/ecpE, ykgK/ecpR and invasion such as fimA, pla, fimC, fimH, fimB, fimE were detected in eight genomes. Mutations in murA, uhpT and glpT conferring a fosfomycin resistance were also present in genomes of 8 K. pneumoniae. IncF was the most common plasmid replicon type detected in all 8 genomes. The study reports high diversity of virulent and multidrug resistant K. pneumoniae in raw milk. Hence, genomic surveillance plans are urgently required for food borne pathogens.

Ceramic Filters Coated with Green Ag-Nanoparticles for Drinking Water Treatment in Rural Households of Nigeria.

A ceramic water filter (CWF) coated with plant-based nanoparticles was used as household water purifier in a rural community. Silver nanoparticles (AgNPs) were produced from the stem bark of Bridelia ferruginea plant, and their efficacy to enhance the physical, chemical, and microbial quality of raw stream water sample was determined using analytical probes and pour-plate techniques, respectively. The pH of the filtered water sample ranged 7.6 to 8.1, which is within the WHO permissible limit for drinking water, and the electrical conductivity values were also reduced from 110 to 70 µS/cm. The CWF coated with AgNPs (CWF-AgNPs) removed Klebsiella pnuemoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Entamoeba histolytica from the stream water sample. The highest percentage of coliform reduction in the CWF and CWF-AgNPs were 93.18% and 99.64%, respectively. The raw data showed that the CWF-NPs enhanced the quality of the stream water. The surface and internal structure of the CWF-AgNPs can be modified by varying the concentration of the composite materials, so as to determine the most effective combination. The improved CWF-AgNPs will enhance achieving United Nations Sustainable Development Goal #6, which focuses on clean water and sanitation.

Study of structural and magnetic traits of cobalt incorporated nickel oxide nanoparticles

Herein, we report the synthesis of Cobalt-incorporated NiO nanoparticles (CoxNi1-xO, x = 0–0.05) fabricated by the sol–gel combustion method using leaf extract of Moringa Oleifera as a fuel. The effect of cobalt doping on NiO NPs was analyzed by different analytical techniques such as XRD, SEM with EDS, UV–Vis, TEM, and VSM. XRD data validates the formation of cubic nickel oxide nanoparticles and the size of nanoparticles varies from 17.04 nm to 20.47 nm. The band gap energy was obtained from UV–vis spectroscopy (2.70 eV–3.18 eV) and a noteworthy blue shift was observed in the spectral span of 200–800 nm. The SEM and TEM micrographs of the fabricated samples display nano-flake-like morphology. Magnetic traits such as coercivity, retentivity, saturation magnetization, squareness ratio magnetic moment, and anisotropy constant were calculated from VSM analysis. Furthermore, pure and doped NiO NPs were tested for their antimicrobial activity against Klebsiella pnuemoniae, Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. Within the mentioned bacterial species, Co-incorporated NiO NPs displayed high growth inhibition against Staphylococcus aureus bacteria (23 mm).

Assessment of Urinary Tract Infection in Symptomatic Geriatric Patients in Port Harcourt Metropolis, Nigeria.

Urinary tract infections are one of the most prevalent infectious diseases presented in medical care facilities as well as community settings. The elderly have increased risk of developing urinary tract infection (UTI) with attendant morbidities and complications.This study was aimed at investigating the UTI prevalence of geriatric (≥65years) patients, their aetiological agents andantimicrobial susceptibility pattern. The study was conducted on urine samplesfrom150geriatric patients in PortHarcourt metropolis, Nigeria. The samples were inoculated onto MacConkey Agar and Cysteine Lactose Electrolyte Deficient (CLED) agar. Isolates were identified based on colonial morphology, Gram staining and Biochemical characterization and antimicrobial susceptibility test was performed on the bacterial isolates using Mueller-Hinton agar (Oxiod, United Kingdom) according to standard techniques. This study revealed that fifty 50 (33.3%) had UTI. The age group (80-89years) had the highest prevalence of UTI (12.6%) followed by (70years to 79years) which had (10.7%) and the lowest was (65years to 69years) with UTI prevalence of (10%). The bacterial isolates were poorly susceptible to all the antimicrobial agents used. Escherichia coli (38%) was the predominant bacterial uropathogen, followed by Staphylococcus aureus (32%), Klebsiella pnuemoniae (20%) and Protues mirabilis (10%) which had the lowest. In addition, this study revealed that the females had a higher prevalence of UTI (19.3%) than the males (14%). This study revealed that UTI in the geriatrics is a serious challenge in our locality. Extensive use of antibiotics in the geriatric have been implicated as likely reason for harboring resistant flora. Therefore, the rational use of antibiotics to is advocated to curtail the fast-rising increase of antimicrobial resistance and improve outcome.

Synthesis, in-vitro and in-silico antibacterial and computational studies of selected thiosemicarbazone-benzaldehyde derivatives as potential antibiotics

Three new Schiff bases, (Z)-2-(4-(dimethylamino)benzylidene)-N-methylhydrazinecarbothioamide (PDM), (Z)-2-(2-hydroxy-5-nitrobenzylidene)-N-methylhydrazinecarbothioamide (5NS) and (Z)-2-(4-cyanobenzylidene)-N-methylhydrazinecarbothioamide (4CN) of thiosemicarbazone-benzaldehyde derivatives were synthesized by condensation reaction. These compounds were formed from the reaction of 4-methyl-3-thiosemicarbazide with p-dimethylaminobenzaldehyde, 5-nitrosalicylaldehyde and 4-formylbenzonitrile respectively. The molecules synthesized were screened against bacterial isolates; Gram-positive (Staphylococcus aureus and Bacillus cereus), and Gram-negative (Klebsiella pnuemoniae and Pseudomonas aeruginosa) bacteria using agar well diffusion technique, supported by molecular docking and theoretical analysis through computational approach adopting a coupled DFT-B3LYP and 6-31G(d) basis set. The in-vitro antibacterial studies proofed that the compounds have a broad-spectrum antibacterial activity against the bacterial isolates while 5NS (21.0 mm) and PDMA (9.5 mm) have higher antibacterial activities than the standard drug, streptomycin against Staphylococcus aureus (16.5 mm) and Pseudomonas aeruginosa (9.0 mm) respectively. Theoretical studies and molecular docking established the fact that these Schiff bases could be explored further as bioactive compounds against bacterial infections and also as corrosion inhibitors of metals in the oil and gas industry.Graphical abstract

Assessment of OqxA and OqxB Resistance Genes in Escherichia coli and Klebsiella pnuemoniae Clinical Isolates Based on Polymerase Chain Reaction from Niger Delta University Teaching Hospital, Yenagoa, Bayelsa State

Antimicrobial resistance continues to pose serious public health challenges. OqxA and OqxB are multidrug resistance genes that confer Escherichia coli and Klebsiella pneumoniae resistance to more than one antibiotics. The purpose of this study was to detect OqxA in Escherichia coli and OqxB in Klebsiella pneumoniae from clinical samples isolated from Niger Delta University, Yenagoa. A total of 50 samples were collected. The bacterial isolates were identified using a standard bacteriological technique, the genes were detected using Polymerase Chain Reaction while the antibiotic susceptibility testing was done by disc diffusion. Of the 50 clinical isolates, 9(18%) were positive for E. coli while 15(30%) were positive for Klebsiella pnuemoniae. The total number of isolates were 18(36%) from male and 32(64%) from females. The susceptibility pattern of the isolates revealed that Escherichia coli exhibited the highest resistance of 100% to Cefuroxime and Augmentin, followed by Gentamycin and Ofloxacin (.55%) and Ciprofloxacin (11.11%) while Klebsiella pneumoniae Nalidixic Acid, Augmentin Cephalexin and Sulfamethoxazole shows 100% resistance respectively. Of the 9 that were E.coli isolates, 8(88.9%) harboured OqX A while of the 15 that were Klebsiella pneumoniae isolates, 13 (86.7%) harboured the OqxB genes. There was 100% resistance to Nalidixic acid, cefuroxime and sulfamethoxazole, with lowest resitance to meropenem (46.7%) and ciprofloxacin (60%). The report clearly demonstrates an urgent need for surveillance against these bacteria especially as they are pathogens of public health concerns to minimize the increasing pace of multidrug resistance conferred on these bacteria by OxAB genes.

ISOLATION AND ANTIMICROBIAL RESISTANCE PHENOTYPE OF Klebsiella pneumonia FROM THE URINE OF SUSPECTED UTI PATIENTS ATTENDING PUBLIC HOSPITALS IN NASARAWA SOUTH SENATORIAL DISTRICT, NASARAWA STATE, NIGERIA

The emergence of antibiotic resistant uropathogenic Klebsiella pnuemoniae is causing major public health crisis worldwide. This study is aimed at Determining the prevalence and antimicrobial resistance phenotypes of the urinary Klebsiella pnuemoniae isolated from patients attending public hospitals in Nasarawa South Senatorial District, Nasarawa State, Nigeria. During the duration of study, urine samples of 375 patients was cultured for the presence of K. pneumonia. A loopful of urine collected in a sterile container was streaked on MacConkey Agar, CLED, and blood agar plates and incubated for 24 hours at 37°C. The identification and resistance to selected antimicrobials were processed in accordance with the approved standards. K. pnuemoniae was found in 38 of the 375 urine samples tested, resulting in an overall prevalence of 10.13%. GHO and GHK shows a lower prevalence of 4.00% each, while DASH demonstrated a higher prevalence of 14.29%. Out-patient (13.19) and females (11.88%) shows higher prevalence of K. pneumonia than in-patient (6.74%) and males (6.14%). Patients aged 25-34 had the highest prevalence (13.82%), while the age group of 54-64 had the lowest prevalence (3.57%). The bacterial isolates demonstrated more resistance to ampicillin (94.74%) and amoxicillin-clavulanic acid (73.6%) compared to cefotaxime (13.16%), ceftriazone (18.42%), ceftazidime and cefoxitin (23.60%), and gentamicin (28.94%). Thirty-three (33) distinct phenotypes were found, with the most common (7.98%) being Ampicillin (AMP), Amoxicillin-Clavulanic acid (AMT), Ciprofloxacin (CIP), Co-trimoxazole (SXT) and Streptomycin (S). The highest multiple antibiotic resistance score (31.57%) is for resistance to three antibiotics, while the lowest (2.63%) is for resistance to one,

Risk factors and molecular epidemiology of fecal carriage of carbapenem resistant Enterobacteriaceae in patients with liver disease

BackgroundCarbapenem resistant Enterobacteriaceae (CRE) colonization is a risk factor for CRE infection. CRE infection results in an increase in mortality in patients with cirrhosis. However, minimal data regarding the prevalence and the risk factors of CRE colonization in patients with liver disease yet without liver transplantation are available. The present study aimed to investigate the prevalence, risk factors and molecular epidemiology characteristics of CRE fecal carriage among patients with liver disease.MethodsStool specimens from 574 adult inpatients with liver disease were collected from December 2020 to April 2021. CRE were screened using selective chromogenic agar medium and identified by the Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS). Antimicrobial susceptibility was determined using the broth microdilution method. Carbapenemase genes were characterized by polymerase chain reaction (PCR) and DNA sequencing. Multilocus sequence typing (MLST) was performed for Carbapenem Resistant Klebsiella pneumoniae (CR-KPN) isolates and Carbapenem Resistant Escherichia Coli (CR-ECO) isolates.ResultsThe total number of stool specimens (732) were collected from 574 patients with liver disease. 43 non-duplicated CRE strains were isolated from 39 patients with a carriage rate of 6.79% (39/574). The carriage rate was 15.60% (17/109) in patients with acute-on-chronic liver failure (ACLF). Multivariate analysis indicated that ACLF (P = 0.018), the history of pulmonary infection within past 3 months (P = 0.001) and the use of third generation cephalosporin/β-lactamases inhibitor within past 3 months (P = 0.000) were independent risk factors of CRE colonization in patients with liver disease. Klebsiella Pnuemoniae (KPN) (51.28%) and Escherichia coli (ECO) (30.77%) were main strains in these patients. All CRE strains showed high resistance to most antimicrobials except for polymyxin B and tigecycline. Most (83.72%, 36/43) of the CRE carried carbapenemase genes. blaKPC-2 was the major carbapenemase gene. The molecular epidemiology of KPN were dominated by ST11, while the STs of ECO were scattered.ConclusionsThe present study revealed that CRE fecal carriage rates were higher in patients with ACLF than in patients without liver failure. ACLF, the history of pulmonary infection within past 3 months and the use of third generation cephalosporin/β-lactamases inhibitor within past 3 months were independent risk factors of CRE colonization in patients with liver disease. Regular CRE screening for hospitalized patients with liver disease should be conducted to limit the spread of CRE strain.

Antibiogram of Klebsiella pneumoniae among population with community acquired urinary tract infection in Enugu State, Nigeria

Antibiotic resistance possesses a serious challenge in the treatment of Urinary Tract Infections (UTIs). This study was therefore designed to determine the antibiogram of K. pneumoniae isolated from individuals presenting with UTIs in communities within Enugu state. A cross-sectional study was conducted from February, 2021 to June, 2021 and a total of 735 patients with community-acquired UTIs in Enugu state, Nigeria, were involved in the study. The patients were assessed clinically and microbiologically for Klebsiella pnuemoniae and antibiogram of the isolates were investigated. Out of 77 isolates of Klebsiella pneumaniae obtained, 29 (37.7%) showed multiple resistant to the antibiotics used, whereas 48 (62.3%) were either susceptible or intermediate. Of all the antibiotics tested, meropenem showed the highest recorded sensitivity to the test organism 63(19.93%), whereas the least sensitivity was observed in co-amoxiclav 11 (3.48%). Antibiogram of urinary K. pneumoniae isolated from rural dwellers showed a significantly high resistance to commonly used antibiotics; thus, the need for regular awareness campaign and antimicrobial resistance surveillance to increase knowledge, improve infection control measures, and check abuse of antibiotics.

Occurrence, Physicochemical Properties and Antibiotic Resistance Patterns of Enteric Bacteria Isolated from Well Water in Ilara-Mokin, Ondo State, Nigeria

Aims: TheoCcurrence and antibiotic resistance patterns of enteric bacteria isolated from well water sources and their physicochemical profile was ascertained in this study. Molecular analysis of the bacterial isolates from well water samples was conducted via polymerase chain reaction (PCR)-based identification.
 Study Design: Experimental design.
 Methodology: A total of 12 wells were collected in triplicates from groundwater sources (wells), and mean values were obtained. The first batch of samples were collected during the dry season in January and February, 2020. The second batch of samples were collected during the rainy season in July 2020. The detection of coliforms and other enteric bacteria were conducted via the most probable number (MPN) method. Polymerase chain reaction (PCR)-based identification and characterization of bacterial isolates were employed. Antibiotic susceptibility test was done using the Kirby Bauer disc diffusion technique. The determination of the physicochemical properties of the well water samples were conducted following customary protocol.
 Results: Well water sample 7 had the highest count at 250 bacterial counts/100ml in the dry season and 200 bacterial counts/100ml in the rainy season, while well water sample 4, 10, and 11 had 14 bacterial counts/100ml in dry season, well water sample 2 had 140 bacterial counts/100ml in the dry season and 250 bacterial counts/100ml in the rainy season, whilst sample 11 had 7 bacterial counts/100ml in the rainy season. Klebsiella pnuemoniae, Escherichia coli, Salmonella typhi and Shigella dysentariae were the Gram-negative organisms enumerated and molecularly-identified as Klebsiella pnuemoniae subsp. Pnuemoniae HS11286, Escherichia coli 0157:H7, Salmonella enterica subsp. Enterica serovar typhimurium and Shigella dysentariae HNCMB 20080 from the well water samples with percentage identity of 97.19%, 87.44%, 80.45% and 96.19% respectively. Klebsiella pnuemoniae showed high resistant rate in augmentin at 67% in dry season and 100% in the rainy season. Shigella dysentariae showed 8.3% resistance to augmentin in the dry season and 75% in the rainy season. E. coli showed 67% and 58% resistance in the dry and rainy season respectively. Water hardness had the highest mean of 98.5 and 99.5 mg/L in dry and rainy season respectively while turbidity, and alkalinity had the least mean value at 1.2 (NTU) and 0.62 mg/L, 1.4 (NTU) and 0.7mg/L in both dry and rainy seasons.
 Conclusion: Findings provided information on the poor quality of the well water, which will be useful in groundwater treatment strategies and policy formulation by appropriate groundwater source protection bodies.

Genetic characterization and passage instability of a novel hybrid virulence plasmid in a ST23 hypervirulent Klebsiella pneumoniae.

Hypervirulent variants of Klebsiella pnuemoniae (hvKP), which causes life-threatening infections, is a global priority pathogen and frequently harbours virulence plasmids. The virulence plasmids have emerged as the predominant vehicles carrying the major pathogenic determinants of hypermucoviscosity and hypervirulence phenotypes. In the present study, we characterized a novel virulence plasmid in AP8555, an ST23 hvKP strain, which induced a metastatic infection and fatal septic shock in a critically ill patient. The serum killing assay, the quantitative biofilm formation assay, the G.mellonella infection model, and the mouse lethality assay demonstrated that AP8555 was almost as virulent as the hvKP strain NUTH-K2044. The plasmid pAP855 could be conjugated to Klebsiella quasipneumoniae ATCC700603 and E. coli J53 at a frequency of 7.2× 10−5 and 8.7× 10−7, respectively. Whole-genome sequencing and bioinformatics analysis confirmed that the plasmid was novel, clustered to the incompatibility type of IncHI1B/IncFIB/IncFII and presented high similarity to the pK2044 plasmid. In contrast, a 130-kb large-fragment insertion was observed on the plasmid, which introduced a genetic hybrid zone with multiple conjugation-related genes of type IV secretion systems (T4SS) and CcdAB toxin-antitoxin systems (TAS) to the plasmid. In the transconjugants, the presence of pAP855 had a negative impact on bacterial fitness, but enhancing the virulence-associated phenotypes. In vitro evolution experiments showed that pAP855 in the transconjugants could not be stably inherited after 10 days of passage. Our study not only reports a novel hybrid plasmid but also highlights the putative pathway of conjugative virulence plasmid formation and evolution by means of genetic rearrangement through sequence insertion. These findings indicate that structural versatility could contribute to the dissemination of cointegrate virulence plasmid, although the plasmid incurred a fitness cost. Therefore, continuous monitoring the acquisition of conjugative virulence plasmids may have critical value for plasmid research and increase awareness of hvKP.

In Vitro Activation of Ampicillin Effect with Plant Extract Cocktail-Mediated Silver Nanoparticles Against Multidrug-Resistant Bacteria Pathogens

Background: The emergence of antibiotic resistance and the continuing evolution of resistance even to newer drugs have always been a global challenge. In the pursuit of innovative solutions, there is growing interest in using nanomaterials with antibacterial potentials to combat this menace. Objectives: In this study, plant extract cocktail-mediated silver nanoparticles (PAgNPs) was used to stimulate the antibacterial effect of ampicillin (AMP) against multidrug-resistant (MDR) bacterial pathogens. Methods: The agar well diffusion technique was used to investigate the potentials of PAgNPs in activating the antibacterial activity of AMP in MDR bacteria, including Escherichia coli, Klebsiella pnuemoniae, Micrococcus luteus, and Clostridium difficile. Plant extract cocktail-mediated silver nanoparticles were synthesized by reacting 9 mL of 1 mM of silver nitrate with 0.5 mL each of Citrus limon juice and aqueous Newbouldia laevis extract under bright sunlight for 10 minutes. Plant extract cocktail-mediated silver nanoparticles were characterized using UV-visible spectroscopy (UV-Vis) and higher resolution transmission electron microscopy (HRTEM) with energy dispersive x-ray spectroscopy (EDS). Results: Plant extract cocktail-mediated silver nanoparticles colloidal solution was reddish-brown with a 441-nm surface plasmon resonance (SPR) absorption peak. The HRTEM micrograph showed the varied shaped silver nanoparticles (AgNPs) with the average size of 23.49 ± 10.49 nm. Similarly, EDS showed a strong typical metallic silver nanocrystallites absorption peak at 3.0 keV. The PAgNPs activate the AMP activity in MDR E. coli, M. luteus, K. pnuemoniae, and C. difficile. Conclusions: The present findings suggest that PAgNPs can be considered a suitable candidate for developing novel antibacterial drugs to combat the growing threat of antibiotic resistance.

Screening and Characterization of Next-Generation Biofuels Producing Bacterial Strains.

Production of fuels from renewable resources is of utmost importance due to fast depletion of fossil resources and related environmental issues. The present study explored the intrinsic capability of microbial strains to produce alka(e)nes, the next-generation biofuel, thus to reduce the dependence upon current petroleum fuels. Eight bacterial strains, namely, SDK-1, SDK-2, SDK-6, SDK-7, SDK-8, SDK-9, SDK-10, and SDK-11 were isolated from sludge and soil samples collected from different sources using lauric acid as a substrate with a potential to produce alka(e)nes. Production of different medium- and long-chain alka(e)nes by these isolates was confirmed via gas chromatography-mass spectrometer (GC-MS) analysis. SDK-1 (7.2%), SDK-2 (3.72%), and SDK-6 (3.52%) produced significant proportion of medium-chain hydrocarbons as compared to SDK-10 and control with no production. These isolates may be further investigated for production of these alternative sources of energy. In contrary, maximum fraction of long-chain hydrocarbons is produced in SDK-8 (75.28%) followed by SDK-9 (61.51%). Similarly more than 50% of the total hydrocarbons produced in SDK-8 constitute fossil mimic hydrocarbons while only 10.78% fractions were found in SDK-10. Since these fractions resemble different hydrocarbons obtained from crude oil, hence may be explored for their wide applications in different fields. Biochemical characterization and sequencing of the 16S rRNA gene revealed the homology of SDK-1, SDK-2 and SDK-6 with Pseudomonas aeruginosa, SDK-7 and SDK-9 with Enterobacter cloacae, SDK-8 with Klebsiella pnuemoniae, SDK-10 with Enterobacter hormaechei and SDK-11 with Pseudomonas nitroreducens, respectively.

Screening of Asymptomatic Bacteriuria in Sickle Cell Pediatric Patients

Abstract Background Asymptomatic bacteriuria (ASB) refers to two consecutive urine cultures growing more than 100,000 colony forming units (CFU)/ml of a bacterial species in a patient with no symptoms of urinary tract infection (UTI). In sickle cell disease (SCD) patients, the anatomical and physiological defects associated with the disease make ASB more prone to worsen the sickle nephropathy and cause more kidney damage. Also, the urine concentration and acidification defects associated with SCD enhance urinary bacterial formation and proliferation. In resource poor settings where renal replacement therapy is limited, early detection and management of ASB in SCD children may retard this progression. Aim of the Work The current study aims to investigate the prevalence of asymptomatic bacteriuria, its major determinants and its effect on kidney functions in SCD patients for early detection and treatment. Patients and Methods The study was conducted at Ain Shams University Children's Hospital and the Main Microbiology Laboratory at Clinical Pathology Department during the period between June 2019 and February 2020.The study included 30 children previously diagnosed as SCD by HB electrophoresis. A fresh voided mid-stream urine samples were collected once from all patients and subjected to urinalysis and culture on chromogenic media. Patients with positive culture results were asked to get another sample to confirm their culture results, while those with contaminated results were re-Instructed with precautions to get another fresh voided mid-stream urine samples. Only significant isolates were identified and subjected to antimicrobial susceptibility testing using disk diffusion method according to CLSI 2017. Patients were divided either into ASB or sterile urine groups according to their culture results. All SCD Patients were subjected to complete blood picture (CBC), reticulocytic count, markers of haemolysis (total, indirect bilirubin and LDH) and serum creatinine. Results The prevalence of confirmed ASB was 16.7% (5/30).All children in ASB group had pyuria(100%). Staph.saprophyticus (60%) (3/5)was the commonest organism isolated from the urine of these patients, followed by E.coli (20%)(1/5) & Klebsiella pnuemoniae (20%)(1/5).Sulfamethoxazole +Trimethoprim (Sutrim) was the most sensitive antibiotic among all isolated microorganisms.The difference in kidney funtion results among the two groups were statistically insignificant. Conclusion Asymptomatic bacteriuria was of high prevalence in SCD pediatric patients in Egypt at Ain Shams University Hospitals. Pyuria was the only major determinant of ASB in this study.Staph.saprophyticus was the predominant organism isolated from ASB group. Sulfamethoxazole +Trimethoprim (Sutrim) was the drug of choice for empirical treatment of UTI. Serum creatinine was a non-sensitive marker to monitor any minor impairment in kidney functions.

Hypervirulent Klebsiella pneumoniae Infections in Pediatric Populations in Beijing (2017-2019): Clinical Characteristics, Molecular Epidemiology and Antimicrobial Susceptibility.

Hypervirulent variants of Klebsiella pnuemoniae (hvKp) are emerging globally causing life-threatening infectious diseases; however, comprehensive studies on pediatric hvKp strains and related infections are still lacking. Clinical data were collected from medical records. Genotype (multilocus sequence typing), capsular serotype, virulence gene profile and carbapenemase of the isolates were determined by PCR and DNA sequencing. Broth microdilution method was adopted to test the antimicrobial susceptibility. Hypermucoviscosity phenotype and the virulence of the strains were evaluated by string test and Galleria mellonella larvae killing assay. Among 319 K. pneumoniae strains, 26 (8.2%) hvKp were identified, the detection rates in 2017, 2018 and 2019 were 1.8%, 5.2% and 11.3%. The majority of hvKp infections were found in school-age children and adolescents (57.7%). Pneumonia was the most common diagnosis (38.5%). Single fatal case was hvKp caused liver abscess complicated with bacteremia. hvKp were dominated by ST23 (30.8%) and ST11 (30.8%). Eight carbapenem-resistant hvKp (CR-hvKp) were found, which all belonged to ST11. Virulence gene profile revealed that ST11 hvKp might carry incomplete pLVPK-like plasmids, but they exhibited comparable in vivo virulence to the other hvKp. The infections caused by hvKp are not frequent among pediatric populations, but the detection rate of hvKp in pediatric populations is increasing rapidly in recent years. The emerging and dissemination of ST11 CR-hvKp should be monitored continuously.

Endophytic fungal isolation from Blumea axillaris: Identification and biological activity of secondary metabolites

Medicinal plants are a wealthy source of natural medicinal properties and remain as base for new drug discoveries. Endophyte from the specific medicinal plants produce the analogous metabolites as that of the host plant. The metabolites from the endophytes comprise maximum therapeutic properties and have been extensively applied in treating various diseases and disorders. This study was focused on identification of the endophytic fungi from the medicinal plant Blumea axillaris and investigates the diversity of endophytic fungi from various explants of the same plant. The explants were cultured on potato dextrose agar and 6 endophytic fungi were successfully isolated from Blumea axillaris. They were identified morphologically and confirmed with molecular analysis as Xylaria arbuscula, Paraphoma radicina, Phomopsis phaseoli, Sordaria fimicola, Aspergillus amstelodami, Diaporthe eucalyptorum. The DNA sequences were analyzed by BLAST and the phylogenetic tree was constructed with neighbor joining method. The six isolates were subjected to antagonistic activity for the selection of potential strain and the bioactive strain Xylaria arbuscula was selected for the production of secondary metabolites by optimization. The parameters like pH, temperature, incubation period, carbon and nitrogen (organic and inorganic source) were optimized for secondary metabolite production. The fungal metabolite was extracted by solvent extraction method using polar and non-polar solvents like propanol, methanol, chloroform, acetone and ethyl acetate. To investigate the bioactivities of the fungal crude extract was subjected first for its antioxidant activity using DPPH radical scavenging method, followed by antimicrobial activity of methanolic (MeOH) extract of Xylaria arbuscula, that were also analyzed by the agar well-diffusion method against the clinical pathogens Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pnuemoniae, Proteus mirabilis, Aspergillus niger and Candida albicans.

In vitro Antibacterial Activities of Honey Bee Extracts against Bacterial Isolates of Wound Infections

Microorganisms most especially bacteria, continue to develop resistance against antimicrobial agents; hence novel sources of antibiotics are urgently needed to reduce this problem. This study was carried out to investigate the antibacterial activities of ethanolic, chloroform and aqueous extracts of Apis mellifera (honey bee) on isolates of wound infections. The isolates used in this study were procured from University of Ilorin Teaching Hospital (UITH) and confirmed using morphological and biochemical tests. The isolates used include; Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pnuemoniae, Proteus mirabilis and Proteus vulgaris. Honey bees were collected from an apitherapist at Sunshine honey and agro foods, Akure, Ondo State Nigeria. The whole insect was used for in vitro antibacterial evaluation of the isolates using agar well diffusion method. Ethanolic extract of A. mellifera had the highest inhibitory activity with mean zones of inhibition ranging from 7.40 mm to 21.67 mm, chloroform extracts had moderate inhibitory activity ranging from 4.63 mm to 10.03 mm while the aqueous extract had the least activity with zones of inhibition ranging from 3.00 mm to 6.30 mm. However, no antibacterial activity was observed against P. aeruginosa for all the extracts. It is concluded that extracts of honey bees most especially the ethanolic extract have antibacterial activity and thus could be a potential antibacterial agent against isolates of wound infections.

Design, Synthesis and Evaluation of Antimicrobial Database-Derived Peptides Against Drug-Resistant Gram-Positive and Gram-Negative Pathogens

Bacterial drug resistance has become a serious problem worldwide as a consequence of long-term use and misuse of antibiotics. Current research trends indicate the development of anti-microbial peptides (AMPs) as a promising alternative to conventional antibiotics and to tackle antibiotic resistance. In the present work, novel short AMPs containing less than 15 amino acids with potential broad-spectrum activity are de-novo designed. A computational database-guided pipeline of rational analysis and modification is developed and utilized based on established principles of AMP activity such as charge, hydrophobicity, length, amino-acid frequency, charge density and hydrophobic moments. Potential broad-spectrum AMP sequences are designed based on a consecutive refinement strategy in which seed AMP sequences with desirable properties are predicted from scratch and then modified for possible improvement inactivity. Finally, four AMP sequences were designed, synthesized and tested for their efficacy in-vitro for broad spectrum anti-microbial activity against major drug resistant pathogens namely two Gram-positive organisms Staphylococcus aureus, Bacillus cereus and two Gram-negative pathogens Klebsiella aerogenes and Klebsiella pnuemoniae. Based on the inhibitory concentrations, two among the four designed peptides namely PEP01 (GKIMYILTKKS) and PEP03 (FGIKLRSVWKR) showed best results as broad-spectrum AMPs among which the sequence of PEP03 is further projected as a better candidate in terms of its predicted cell-penetrating and non-toxic nature.

Antimicrobial assessment of polyphenolic extracts from onion (Allium cepa L.) skin of fifteen cultivars by sonication-assisted extraction method

Onion skin possesses various health benefits due to its phenolic and antimicrobial components. In this study, sonication-assisted extracts of onion skin of differentially coloured cultivars (dark-red, red, pink and white) were investigated for their antimicrobial activity against six pathogenic bacteria. Antimicrobial efficacy of fifteen different coloured extracts was analysed by agar well-diffusion assay with principal component analysis (PCA) for comprehensive investigation. Result showed skin extracts of pink cultivars (cv.) significantly (P ≤ 0.05) effective against pathogenic bacteria followed by red and dark red skin. White skin showed least effect on the growth of bacteria. Skin of cv. ‘Phursungi Local’ (pink) and cv. ‘Hissar-3’ (pink) showed best range of inhibition against Staphylococcus aureus, Klebsiella pnuemoniae, Bacillus cereus and Solmonella typhimurium compared to other. Only white skin extracts of cv. ‘Bhima Shubhra’ and ‘Udaipur Local’ inhibited the growth of Pseudomonas aeruginosa up to 4.0 ± 0.0 mm. Minimum inhibitory concentration (MIC) of the effective extracts was also elucidated in the range between 0.09 – 9.0 mg/mL. Skin extracts of cv. ‘Hissar-2’ (red) and ‘Bhima Shubhra’ (white) showed better inhibition at the concentration of 0.45 and 0.72 mg/mL against Streptococcus agalactiae and Pseudomonas aeruginosa, respectively. As per correlation analysis, positive correlation was obtained between total flavonoids and inhibition rate of all the bacteria while a weak correlation (R2 = 0.3967) was observed against Pseudomonas aeruginosa. The waste skin of the analysed cultivars can be utilised in food and health sector as natural preservative and antimicrobial agent.