Incidence, risk factors and clinical outcome of multidrug-resistant organisms after heart transplantation

BACKGROUND Transplant recipients commonly harbor multidrug-resistant organisms(MDROs),as a result of frequent hospital admissions and increased exposure to antimi-crobials and invasive procedures.AIM To investigate the impact of patient demographic and clinical characteristics on MDRO acquisition,as well as the impact of MDRO acquisition on intensive care unit(ICU)and hospital length of stay,and on ICU mortality and 1-year mortality post heart transplantation.METHODS This retrospective cohort study analyzed 98 consecutive heart transplant patients over a ten-year period(2013-2022)in a single transplantation center.Data was collected regarding MDROs commonly encountered in critical care.RESULTS Among the 98 transplanted patients(70%male),about a third(32%)acquired or already harbored MDROs upon transplantation(MDRO group),while two thirds did not(MDRO-free group).The prevalent MDROs were Acinetobacter baumannii(14%),Pseudomonas aeruginosa(12%)and Klebsiella pneumoniae(11%).Compared to MDRO-free patients,the MDRO group was characterized by higher body mass index(P=0.002),higher rates of renal failure(P=0.017),primary graft dysfunction(10%vs 4.5%,P=0.001),surgical re-exploration(34%vs 14%,P=0.017),mechanical circulatory support(47%vs 26%P=0.037)and renal replacement therapy(28%vs 9%,P=0.014),as well as longer extracorporeal circulation time(median 210 vs 161 min,P=0.003).The median length of stay was longer in the MDRO group,namely ICU stay was 16 vs 9 d in the MDRO-free group(P=0.001),and hospital stay was 38 vs 28 d(P=0.006),while 1-year mortality was higher(28%vs 7.6%,log-rank-χ2:7.34).CONCLUSION Following heart transplantation,a predominance of Gram-negative MDROs was noted.MDRO acquisition was associated with higher complication rates,prolonged ICU and total hospital stay,and higher post-transplantation mortality.

Epidemiology and Clonal Spread Evidence of Carbapenem-Resistant Organisms in the Center of Care and Protection of Orphaned Children, Vietnam

Objective: To determine the prevalence of colonization and transmission of carbapenem-resistant Gram-negative organisms in order to develop of an effective infection prevention program. Design: Cross-sectional study with carbapenem-resistant organisms (CRO) colonization detection from the fecal specimens of 20 Health Care Workers (HCWs) and 67 residents and 175 random environment specimens from September 2022 to September 2023. Setting: A Care and Protection Centre of Orphaned Children in South of HCM City. Participants: It included 20 HCWs, 67 residents, and 175 randomly collected environmental specimens. Method: Rectal and environmental swabs were collected from 20 HCWs, 67 residents (most of them were children), and 175 environmental specimens. MELAB Chromogenic CARBA agar plates, Card NID, and NMIC-500 CPO of the BD Phoenix TM Automated Microbiology System and whole genome sequencing (WGS) were the tests to screen, confirm CROs, respectively and determine CRO colonization and transmission between HCWs, residents, and the environment. Result: We detected 36 CRO isolates, including 6, 11 and 19 CROs found in 6 HCWs, 10 residents and 19 environments. The prevalence of detectable CRO was 30% (6/20) in HCWs, 14.92% (10/67) in residents, and 10.86% (19/175) in environmental swabs in our study. WGS demonstrated CRO colonization and transmission with the clonal spread of E. coli and A. nosocomialis, among HCWs and residents (children). Conclusion: Significant CRO colonization and transmission was evident in HCWs, residents, and the center environment. Cleaning and disinfection of the environment and performing regular hand hygiene are priorities to reduce the risk of CRO colonization and transmission.

Analysis of Multi-Drug Resistant Organism Surveillance and Antimicrobial Resistance Early Warning in a Hospital in 2022

Objective:To determine the clinical distribution of multi-drug resistant organism(MDRO)in Jiangyan Hospital and the monitoring and warning of drug-resistance bacteria to provide an important basis for guiding the application of broad-spectrum antibiotics in clinical treatment and reducing the occurrence of nosocomial infection.Methods:Retrospective screening and analysis were conducted on the pathogenic strains of hospitalized patients in our hospital in 2022.Results:A total of 2,769 strains of pathogenic bacteria and 390 strains of MDRO were detected and isolated in our hospital in 2022;the detection rate of MDRO was 14.08%.A total of 516 strains(18.64%)Klebsiella pneumoniae(KP)and 62 strains(12.02%)of carbapenem-resistant Klebsiella pneumoniae(CR-KP)were detected;436 strains(15.75%)of Escherichia coli(ECO)were detected,including 8 strains(1.83%)of CR-ECO;342 strains(12.35%)of Pseudomonas aeruginosa(PA)and 116 strains(33.92%)of CR-PA were detected;there were 194 strains(7.01%)of Acinetobacter baumannii(AB),among which 125 strains(64.43%)were CR-AB;there were 291 strains(10.51%)of Staphylococcus aureus,among which 79 strains(27.15%)of methicillin-resistant Staphylococcus aureus(MRSA)were detected;78 strains(2.82%)of Enterococcus faecalis were detected,and vancomycin-resistant enterococcus(VRE)was not detected.The first five MDROs were CR-AB,CR-PA,MRSA,CR-KP,and CR-ECO.The top five departments with the highest MDRO detection rate in 2022 were the ICU(37.44%),the Pulmonology Department(ward 13;31.03%),the Department of Rehabilitation(ward 5;6.67%),the Department of Neurosurgery(ward 11;4.62%),and the Department of General Surgery(ward 10;3.59 The resistance rate of antibacterial drugs is divided into four levels for early warning:30%to 40%,41%to 50%,51%to 75%,and 75%or more.Conclusion:Our hospital should strengthen the monitoring of antimicrobial resistance warning related to MDRO and the abuse of antimicrobial drugs.Based on the results of drug sensitivity and antimicrobial resistance warning,the use of antibiotics should be standardized in clinical practice to reduce nosocomial infection。

Multidrug resistant organism infections in patients with COVID-19:risk factors and outcomes

Background:Coronavirus disease 2019(COVID-19)has now spread to most countries and regions of the world.Risk factors associated with multi-drug resistant organism(MDRO)infections in patients with COVID-19 have not been well studied yet.In the present study,we aimed to identify the risk factors associated with the MDRO infections and their impact on in-hospital mortality of COVID-19 patients.Methods:This retrospective cohort study was conducted between December 2019 and April 2020 at two tertiary hospitals in Wuhan,China.Data of cases were collected through electronic medical records system.This study was focused on cases with bacterial culture records.Risk factors and outcomes associated with MDRO infections were analyzed using logistic regression model.Results:Of the 2891 patients,370 patients have bacterial culture results,and MDROs were isolated in 38 patients.Respiratory tract infections(67.3%)were the most common hospital acquired infections.Variables independently associated with MDRO infections were dyspnea at admission(odds ratio(OR)4.74;95%confidence interval(CI)2.06-10.88;P<0.001),intensive care unit(ICU)admission(OR 5.02;95%CI 1.99-12.63;P<0.01),and invasive mechanical ventilation(OR 5.13;95%CI 2.15-12.27;P<0.001),adjusted for age and gender.MDROs infection was also a significant risk factor of death for the patients,adjusted for age,gender,severity of illness,ICU admission and mechanical ventilation(OR 1.12,95%CI:0.43-2.96,P=0.817).Conclusion:In our study,dyspnea at admission,ICU admission and invasive mechanical ventilation were associated with the presence of MDRO infections,and clinicians should be alert in MDRO infections in COVID-19 hospitalized patients.

Direct and Residual Microbicidal Efficacy of Various Antiseptics against Multi-Drug Resistant Bacteria

Background: Infections in ICU’s patients are known to often originate from the colonization of wounds by the patient’s endogenous microbiota, and to eventually lead to secondary sepsis. Aim: to compare in vitro the direct and residual effects after different exposure times of 4% chlorhexidine, and of 0.1% and 0.04% polyhexanide (in gel and solution forms), on ATCC-microorganisms, and too, on bacterial strains obtained from ICU patients. Methods: We used wild multi-drug resistant strains recently obtained from the wounds of patients hospitalized at ICU and reference strains from the American Type Culture Collection (ATCC). Chlorhexidine 4% was studied as a reference solution. The direct and residual effects of the 0.1% and 0.04% polyhexanide, in gel and solution forms, were analyzed using cotton germ carriers. To evaluate the direct effect, we exposed the strains to the antiseptic. To assess the residual effect, the germ-carriers were impregnated with antiseptic and were allowed to dry before we contaminated them. We inoculated the germ carriers in a culture medium with an inhibitor of antiseptic effect to count the number of surviving microorganisms. Findings: 0.1% Polyhexanide solution proved a direct and residual efficacy after 24 hours equivalent to 4% chlorhexidine. Is very important to highlight that this great efficacy did not change according to whether they were ATCC or multidrug-resistant strains. Conclusions: 0.1% polyhexanide demonstrated a great direct and residual efficacy (like 4% chlorhexidine), against multi-drug resistant strains isolated from ICU’s patients. Moreover, due to its few cytotoxicity against keratinocytes and fibroblasts can be an optimal antiseptic for burns, wounds or ulcers.

Multidrug-resistant organisms in intensive care units and logistic analysis of risk factors

BACKGROUND Intensive care unit(ICU)patients are critically ill and have low immunity.They will undergo various trauma medical procedures during diagnosis and treatment.The use of high-dose hormones and broad-spectrum antibiotics will increase the incidence of nosocomial infection in ICU patients.Therefore,it is necessary to explore the causes of nosocomial infection in ICU and provide basis for the prevention and control of nosocomial infection in ICU.AIM To explore major pathogens of nosocomial infection in ICUs,methods of detection and drug resistance trends.METHODS Risk factors of multidrug-resistant infection were analyzed to provide a basis for clinical rational use of antimicrobial drugs in the ICU.These findings were used to standardize rational use of antimicrobial agents.BD PhoenixTM100 automatic bacterial identification analyzer was used to for cell identification in specimens collected from the ICU between January 2016 and December 2019.Drug sensitivity tests were carried out and drug resistance trends were analyzed using the optical disc diffusion method.Odds ratios and corresponding 95%CI of independent variables were calculated using a logistic regression model.Backward elimination(trend=0.1)was used as an inclusion criterion for multivariate analysis.All data were analyzed using SPSS version 22.0,and P<0.05 was considered statistically significant.RESULTS We collected 2070 samples from ICU patients between January 2016 and December 2019.Sample types comprised sputum(1139 strains,55.02%),blood(521 strains,25.17%),and drainage fluid(117 strains,5.65%).A total of 1051 strains of major pathogens,including Acinetobacter baumannii,Escherichia coli(E.coli),Pseudomonas aeruginosa(P.aeruginosa),Klebsiella pneumoniae(K.pneumoniae)and Staphylococcus aureus,were detected,with a detection rate of 35.97%(378/1051).Most of these strains were resistant to antibiotics.Detection rate of E.coli was 21.79%(229/1051),and it was generally sensitive to many antimicrobial drugs.Detection rate of P.aeruginosa was 24.74%(260/1051),and showed low sensitivity to most antibiotics.Detection rate of K.pneumoniae was 9.42%(99/1051),which was generally resistant to multiple antimicrobial drugs and resistant forms.K.pneumoniae was resistant to imipenem for approximate 4 years,and showed a 19.9%(19/99)and 20.20%(20/99)rate of meropenem resistance.Logistic analysis showed that mechanical ventilation and ureteral intubation were risk factors for multidrug-resistant bacterial infections.CONCLUSION This study showed a high incidence of ICU infections.Mechanical ventilation and urine tube intubation were risk factors for infection with multidrug-resistant bacteria.

Antimicrobial activity of green tea extract against isolates of methicillin-resistant Staphylococcus aureus and multi-drug resistant Pseudomonas aeruginosa

Objective:To evaluate antibacterial activity of the Indonesian water soluble green tea extract,Camellia sinensis,against clinical isolates of methicillin-resistantStaphylococcus aureus (S.aureus)(MRSA)and multi-drug resistant Pseudomonas aeruginosa(MDR-P.aeruginosa).Methods:Antimicrobial activity of green tea extract was determined by the disc diffusion method and the minimum inhibitory concentration(MIC)was determined by the twofold serial broth dilutions method.The tested bacteria using in this study were the standard strains and multi-drug resistant clinical isolates of S.aureus and P.aeruginosa,obtained from Laboratory of Clinical Microbiology,Faculty of Medicine,University of Indonesia.Results:The results showed that the inhibition zone diameter of green tea extracts forS.aureus ATCC 25923 and MRSA were(18.970依0.287)mm,and(19.130依0.250)mm respectively.While the inhibition zone diameter forP.aeruginosa ATCC 27853 and MDR-P.aeruginosawere(17.550依0.393)mm and(17.670依0.398)mm respectively.The MIC of green tea extracts againstS.aureus ATCC 25923 and MRSA were 400μg/mL and 400μg/mL,respectively,whereas the MIC for P.aeruginosa ATCC 27853 and MDR-P.aeruginosawere 800μg/mL,and 800μg/mL,respectively.Conclusions:Camellia sinensisleaves extract could be useful in combating emerging drug-resistance caused by MRSA andP.aeruginosa.

Cytotoxic and antibacterial substances against multi-drug resistant pathogens from marine sponge symbiont:Citrinin,a secondary metabolite of Penicillium sp.

Objective:To Isolate,purify,characterize,and evaluate the bioaclive compounds from the sponge-derived fungus Penicillium sp.FF001 and to elucidate its structure.Methods:The fungal strain FF001 with an interesting bioactivity profile was isolated from a marine Fijian sponge Melophlus sp.Based on conidiophores aggregation,conidia development and mycelia morphological characteristics,the isolate FF001 was classically identified as a Penicillium sp.The bioactive compound was identified using various spectral analysis of UV,high resolution electrospray ionization mass spectra,1H and 13C NMR spectral data.Further minimum inhibitory concentrations(MICs)assay and brine shrimp cytotoxicity assay were also carried out to evaluate the biological properties of the purified compound.Results:Bioassay guided fractionation of the EtOAc extract of a static culture of this Penicillium sp.by different chromatographic methods led the isolation of an antibacterial,anticryptococcal and cytotoxic active compound,which was identified as citrinin(1).Further,citrinin(1)is reported for its potent antibacterial activity against methicillin-resistant Staphylococcus aureus(S.aureus),rifampicin-resistant 5.aureus,wild type S.aureus and vancomycin-resistant Enterococcus faecium showed MICs of 3.90,0.97,1.95 and7.81μg/mL,respectively.Further citrinin(1)displayed significant activity against the pathogenic yeast Cryptococcus neoformans(MIC 3.90μg/mL),and exhibited cytotoxicity against brine shrimp larvae LD_(50)of 96μg/mL.Conclusions:Citrinin(1)is reported from sponge associated Penicillium sp.from this study and for its strong antibacterial activity against multi-drug resistant human pathogens including cytotoxicity against brine shrimp larvae,which indicated that sponge associated Penicillium spp.are promising sources of natural bioactive metabolites.

Production systems and important antimicrobial resistant-pathogenic bacteria in poultry:a review

Economic losses and market constraints caused by bacterial diseases such as colibacillosis due to avian pathogenic Escherichia coli and necrotic enteritis due to Clostridium perfringens remain major problems for poultry producers,despite substantial efforts in prevention and control.Antibiotics have been used not only for the treatment and prevention of such diseases,but also for growth promotion.Consequently,these practices have been linked to the selection and spread of antimicrobial resistant bacteria which constitute a significant global threat to humans,ani-mals,and the environment.To break down the antimicrobial resistance(AMR),poultry producers are restricting the antimicrobial use(AMU)while adopting the antibiotic-free(ABF)and organic production practices to satisfy consum-ers’demands.However,it is not well understood how ABF and organic poultry production practices influence AMR profiles in the poultry gut microbiome.Various Gram-negative(Salmonella enterica serovars,Campylobacter jejuni/coli,E.coli)and Gram-positive(Enterococcus spp.,Staphylococcus spp.and C.perfringens)bacteria harboring multiple AMR determinants have been reported in poultry including organically-and ABF-raised chickens.In this review,we discussed major poultry production systems(conventional,ABF and organic)and their impacts on AMR in some potential pathogenic Gram-negative and Gram-positive bacteria which could allow identifying issues and opportuni-ties to develop efficient and safe production practices in controlling pathogens.

<i>In Vitro</i>Antibacterial Activity of Flavonoid Extracts of Two Selected Libyan Algae against Multi-Drug Resistant Bacteria Isolated from Food Products

This study aimed to evaluate the antibacterial activity of flavonoids extracted from two Libyan brown algae namely Cystoseira compressa and Padina pavonica using microwave-assisted extraction method against pathogenic bacteria isolated from meat, meat products, milk and dairy products (Staphylococcus aureus subsp. aureus (5 isolates), Bacillus cereus (3 isolates), Bacillus pumilus (1 isolate), Salmonella enterica subsp. enteric (4 isolates) and Enterohaemor-rhagic Escherichia coli O157 (EHEC O157) (4 isolates)). All of these isolates were muti-drug resistant with high MAR index. The results showed that C. compressa extract exhibited better and stronger antibacterial activities against the seventeen tested isolates with inhibition zones diameter ranged from 14 - 22 mm compared to P. pavonica extract which showed positive effect against 9 isolates with low inhibition zone ranged from 11 - 16.5 mm. Flavonoids extracted from C. compressa also displayed the best spectrum of bactericidal effect with a ratio MBC/MIC ≤ 4 obtained on all susceptible tested bacterial strains. Flavonoids and proanthocyanidins significantly contributed to the antibacterial properties. The mode of action of these active extracts is under investigation.

Bending Resistance Covalent Organic Framework Superlattice:“Nano‑Hourglass”‑Induced Charge Accumulation for Flexible In‑Plane Micro‑Supercapacitors

Covalent organic framework(COF)film with highly exposed active sites is considered as the promising flexible selfsupported electrode for in-plane microsupercapacitor(MSC).Superlattice configuration assembled alternately by different nanofilms based on van der Waals force can integrate the advantages of each isolated layer to exhibit unexpected performances as MSC film electrodes,which may be a novel option to ensure energy output.Herein,a mesoporous free-standing A-COF nanofilm(pore size is 3.9 nm,averaged thickness is 4.1 nm)with imine bond linkage and a microporous B-COF nanofilm(pore size is 1.5 nm,averaged thickness is 9.3 nm)withβ-keto-enamine-linkages are prepared,and for the first time,we assembly the two lattice matching films into sandwich-type superlattices via layer-by-layer transfer,in which ABA–COF superlattice stacking into a“nano-hourglass”steric configuration that can accelerate the dynamic charge transportation/accumulation and promote the sufficient redox reactions to energy storage.The fabricated flexible MSC–ABA–COF exhibits the highest intrinsic CV of 927.9 F cm^(−3) at 10 mV s^(−1) than reported two-dimensional alloy,graphite-like carbon and undoped COF-based MSC devices so far,and shows a bending-resistant energy density of 63.2 mWh cm^(−3) even after high-angle and repeat arbitrary bending from 0 to 180°.This work provides a feasible way to meet the demand for future miniaturization and wearable electronics.

Detection of Multi-drug Resistant Acinetobacter Lwoffii Isolated from Soil of Mink Farm

There were 4 Acinetobacter lwoffii obtained from soil samples.The antimicrobial susceptibility of the strains to 16 antimicrobial agents was investigated using K-B method.Three isolates showed the multi-drug resistance.The presence of resistance genes and integrons was determined using PCR.The aadA 1,aac（3＇）-IIc,aph（3＇）-VII,aac（6＇）-Ib,sul2,cat2,floR,and tet（K）genes were detected,respectively.

Prevalence of Some World Health Organization Priority Organisms from an Abattoir at Kwata, Anambra State, Nigeria

The abattoir is one of the important sectors in the food industry, therefore the need for close monitoring of everything concerning it to minimize microbial contamination. The aim of the study is to identify bacteria listed as WHO priority organisms associated with meat from Kwata abattoir in Awka, Anambra state. The study was carried out over a three (3) months period from September to December 2022. Thirteen samples were collected from the floor, table, water, meat, knife and soil in the abattoir. The samples were cultured using streak and spread plate methods on MacConkey and Cetrimide agar. The isolates were identified with the following biochemical tests: catalase, oxidase, citrate and indole tests. Ampiclox levofloxacin, gentamicin, ofloxacin impenem ceftraixone, cefixime, cefuroxime and nitrofurantoin were used for sensitivity test following Kirby Bauer disc diffusion method and biofilm formation was determined using the tube method. The 75 isolates obtained were identified as follows;29.3% E. coli, 26.7% Klebsiella spp., 16% Proteus spp., and 28% Pseudomonas spp. The result of antibiotics sensitivity test interpreted using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints showed that (98%) of the isolates were resistant to the antibiotics used. Test for biofilm formation with 52 isolates showed 31 strong, 12 moderate and 9 weak biofilm formers. The result of this study confirms the presence of bacteria contaminants within the WHO priority list in the abattoir, as such there is need for improved handling of animals. Slaughtering, cleaning and distribution of meat should be done using aseptic procedures. .

Rational surface charge engineering of haloalkane dehalogenase for boosting the enzymatic performance in organic solvent solutions

Biocatalysis in organic solvents(OSs)has numerous important applications,but native enzymes in OSs often exhibit limited catalytic performance.Herein,we proposed a computation-aided surface charge engineering strategy to improve the catalytic performance of haloalkane dehalogenase DhaA in OSs based on the energetic analysis of substrate binding to the DhaA surface.Several variants with enhanced OS resistance were obtained by replacing negative charged residues on the surface with positive charged residue(Arg).Particularly,a four-substitution variant E16R/E93R/E121R/E257R exhibited the best catalytic performance(five-fold improvement in OS resistance and seven-fold half-life increase in 40%(vol)dimethylsulfoxide).As a result,the overall catalytic performance of the variant could be at least 26 times higher than the wild-type DhaA.Fluorescence spectroscopy and molecular dynamics simulation studies revealed that the residue substitution mainly enhanced OS resistance from four aspects:(a)improved the overall structural stability,(b)increased the hydrophobicity of the local microenvironment around the catalytic triad,(c)enriched the hydrophobic substrate around the enzyme molecule,and(d)lowered the contact frequency between OS molecules and the catalytic triad.Our findings validate that computationaided surface charge engineering is an effective and ingenious rational strategy for tailoring enzyme performance in OSs.

Clinical characteristics, target organ damage and associate risk factors ofresistant hypertension determined by ambulatory blood pressure monitoringin patients aged ≥80 years

Objectives To investigate clinical characteristics, target organ damage, and the associated risk factors of the patients aged ≥ 80 yearswith true resistant hypertension （RH）. Methods Patients aged ≥ 80 years with hypertension （n = 1163） were included in this study. Theincluded participants attended a structured clinical examination and an evaluation of RH was carried out. The prevalence, clinical characteristicsand target organ damage of patients with RH were assessed. The associated clinical risk factors were analyzed by using logistic regression.Results The prevalence of RH diagnosis by 24-h ambulatory blood pressure monitoring assessment was 21.15%. End-diastolic left ven-tricular internal dimension, left ventricular mass index as well as prevalence of left ventricular hypertrophy were significantly greater in pa-tients with RH than in control group. The common carotid artery intimal media thickness, carotid walls thickness, common carotid arterydiameter and relative wall thickness were significant greater in RH group than in control. A relatively higher level of creatinine, estimatedglomerular filtration rate, microalbuminuria and retinal changes was found in RIt group than in control. A multivariate analysis showed thatpatients with a history of diabetes, higher body mass index （BMI） and lipid profiles were independent risk factors of RH. Conclusions Theprevalence of RH in patients aged ≥ 80 years was within the range of reported rates of the general population. Subjects with RH diagnosisshowed a higher occurrence of target organ damage than patients with well controlled blood pressure. Patients with diabetes, higher BMI andserum lipid profiles were independent risk factors for RH in patients aged ≥ 80 years.

Production and purification of a bioactive substance against multi-drug resistant human pathogens from the marine-sponge-derived Salinispora sp.

Objective:To isolate,purify,characterize,elucidate structure and evaluate bioactive compounds from the sponge-derived Salinispora sp.FS-0034.Methods:The symbiotic actinomycete strain FS-0034 with an interesting bioactivity profile was isolated from the Fijian marine sponge Theonella sp.Based on colony morphology and obligatory requirement of seawater for growth,and mycelia morphological characteristics the isolate FS-0034 was identified as a Salinispora sp.The bioactive compound was identified by using various spectral analysis of ultraviolet,high resolution electrospray ionization mass spectroscopy,H nuclear magnetic resonance,correlated spectroscopy and heteronuclear multiple bond coherence spectral data.A minimum inhibitory concentration assay were performed to evaluate the biological properties of the pure compound against multi-drug resistant pathogens.Results:Bioassay guided fractionation of the ethyl acetate extract of the culture of Salinispora sp.FS-0034 by different chromatographic methods yielded the isolation of an antibacterial compound,which was identified as rifamycin W(compound 1).Rifamycin W was reported for its potent antibacterial activity against methicillin-resistant Staphylococcus aureus,wild type Staphylococcus aureus and vancomycin-resistant Enterococcus faecium and displayed minimum inhibitory concentrations of 15.62,7.80 and 250.00 μg/mL,respectively.Conclusions:The present study reported the rifamycin W from sponge-associated Salinispora sp.and it exhibited appreciable antibacterial activity against multi-drug resistant human pathogens which indicated that sponge-associated Actinobacteria are significant sources of bioactive metabolites.

Suppressing Leakage Currents and Improving Performance of Indoor Organic Photovoltaic Devices

Organic photovoltaic(OPV) devices hold great promise for indoor light harvesting,offering a theoretical upper limit of power conversion efficiency that surpasses that of other photovoltaic technologies.However,the presence of high leakage currents in OPV devices commonly constrains their effective performance under indoor conditions.In this study,we identified that the origin of the high leakage currents in OPV devices lay in pinhole defects present within the active layer(AL).By integrating an automated spin-coating strategy with sequential deposition processes,we achieved the compactness of the AL and minimized the occurrence of pinhole defects therein.Experimental findings demonstrated that with an increase in the number of deposition cycles,the density of pinhole defects in the AL underwent a marked reduction.Consequently,the leakage current experienced a substantial decrease by several orders of magnitude which achieved through well-calibrated AL deposition procedures.This enabled a twofold enhancement in the power conversion efficiency(PCE) of the OPV devices under conditions of indoor illumination.

Prevalence of multi-drug resistant uropathogenic Escherichia coli in Potohar region of Pakistan

Objective:To scrutinize patterns of multi-drug-resistant uropathogenic Escherichia coli(UPEC) strains and particularly of fluoroquinolone-resistance this is an alternative choice for the treatment of urinary tract infections.Methods:Bacterial samples(n = 250) were collected from out-patients from August 2012 to August 2014 Islamabad.Antibiotic susceptibility profiling and determination of minimum inhibitory concentrations(MICs) and minimum bactericidal concentrations were performed according to the guidelines of Clinical and Laboratory Standards Institute(CLSI,2012).Genes,qnrA,qnrB and qnrS were identified by DNA amplification and sequencing.Results:The highest percentage of UPEC isolates were resistant to co-trimoxazole(82%) followed by cephalothin(80%),2nd Gen,3rd Gen and 4th Gen cephalosporins,respectively.Resistance against gentamicin,amikacin remained 29% and 4%.For other drugs including nitrofurantoin,tetracycline,carbapenem and beta-lactam inhibitors remained below 10%.Altogether,59% of the isolates were resistant to at least three antibiotics including one fluoroquinolone.Overall,MICs for ciprofloxacin remained(MIC≥256 μg/mL) and for levofloxacin(MIC≥16 μg/mL and 32 μg/mL).No significant differences were observed regarding MIC values of extended spectrumβ-lactamase(ESBL) and non-ESBL producers.For qnrS and qnrB positive isolates MICs remained above 32 μg/mL.Prevalence of UPEC was significantly higher among females and 40% of the isolates were ESBL producers.Conclusions:Higher percentages of ESBL producing UPEC were associated with urinary tract infections.Moreover,the majority of these isolates were multi-drug resistant and fluoroquinolone-resistant.

Molecular characteristics,antibiogram and prevalence of multi-drug resistant Staphylococcus aureus (MDRSA) isolated from milk obtained from culled dairy cows and from cows with acute clinical mastitis

To study the molecular characteristics, antibiogram and prevalence of multi-drug resistant Staphylococcus aureus (S. aureus) (MDRSA) isolated from milk obtained from culled dairy cows and from cows with acute clinical mastitis.MethodsBacteria were cultured from 188 quarter milk samples obtained from cows before culling (n = 139) and from cows affected with acute mastitis (n = 49) belonging to 10 dairy farms. The bacteria were identified using colony morphology, Gram staining and biochemical characteristics. S. aureus isolates were then subjected to molecular characterization using PCR targeting 16S rRNA and mecA gene to identify Methicillin resistant S. aureus (MRSA). The antibiogram of all isolates was performed using the Kirby-Bauer disk diffusion method against 10 commonly used antibiotics in dairy farms.ResultsS. aureus was isolated from 19 (13.7%) samples obtained from culled cows and 11 (22.4%) samples obtained from cows with acute mastitis. In both culled cows and cows with acute mastitis, in vitro antibiogram revealed that 100% of S. aureus isolates were resistant to erythromycin, penicillin G, streptomycin, doxycyclin, and trimethoprim/sulpha. The prevalence of MRSA in milk of culled cows and cows with acute mastitis was 26.3% and 18.2%, respectively, with an overall prevalence of 3.7% among all samples. All MRSA isolates were completely resistant to all tested antibiotics. All MRSA isolates were positive for the presence of the mecA gene.ConclusionsMRSA carrying the mecA gene were isolated from mastitic milk from dairy cows in Jordan for the first time. MRSA may pose a potential health risk to the public, farm workers and veterinarians.

Bacterial contamination of orally-consumed crude herbal remedies:A potential source for multi-drug resistant pathogens in man

Objective:The acceptability of herbal remedies for alleviating discomforts and ill-health has become very popular, on the account of the increasing cost of allopathic medicine for personal health maintenance.The observable non-adherence of herbalists to the established World Health Organization(WHO) / National Agency for Food and Drug Administration Control(NAFDAC) regulations for the quality control of herbal medicines is an issue for concern.In view of this,34 popular and widely consumed crude herbal remedies in southwestern,Nigeria were screened for compliance with standard limits for bacterial contamination,bacteria flora and their antibiotic susceptibility pattern.Methods:Isolates recovered from samples were identified using the cultural, morphological and biochemical characteristics.They were also tested for drug sensitivity using standard procedures. Results:A heavy bacteria load ranging from 3.00×10~3-9.58×10~5 CFU/ML and 1.20×10~5- 5.41×10~5 CFU/ML was observed for water and spirit extracted preparations respectively.The bacteria flora cum contaminants were:Staphylococcus aureus,Bacillus cereus,Bacillus subtilis,Pseudomonas aeruginosa, Micrococcus luteus,Lactobacillus plantarum,Klebsiella pneumoniae,Escherichia coli,streptococcus,Shigella, Neisseria,Arthrobacter,Kurthia and Clostridium species.All the isolates were multi-drug resistant(MDR) strains.Conclusion:The crude herbal preparations consumed in Nigeria failed to comply with the internationally recognized standards regarding bacteria load and flora.The presence of MDR pathogens is of greatest concern. It poses a great risk to consumers health and could be a source of introducing MDR organisms into the human population.There is the need for the enforcement of established guidelines to ensure the safety of these preparations.