Disc Diffusion Method Research Articles

Multicentre evaluation of in vitro activity of contezolid against drug-resistant Staphylococcus and Enterococcus.

To investigate susceptibility to contezolid, a novel oxazolidinone, multicentre surveillance was conducted involving 2449 strains of Staphylococcus and Enterococcus collected from 65 hospitals across China. The MICs of contezolid, linezolid and other clinically significant antibiotics were determined by the broth microdilution method. Consistency with the broth microdilution method for contezolid was assessed using agar dilution method, as well as disc diffusion and ETEST for linezolid, respectively. WGS was conducted on all 20 linezolid-resistant and 30 randomly non-resistant strains to analyse linezolid resistance genes (optrA, poxtA, cfr) and 23S rRNA mutation sites. All strains exhibited WT susceptibility to contezolid, while resistance proportions to daptomycin, vancomycin, teicoplanin, tigecycline and eravacycline ranged from 0% to 5.2% in Staphylococcus, and from 0% to 7.8% in Enterococcus. Linezolid resistance was higher in Enterococcus faecalis (4.4%) compared with Enterococcus faecium (0.2%). Contezolid showed a lower MIC50 (0.5 mg/L) than linezolid (2 mg/L) for methicillin-resistant Staphylococcus. Against Enterococcus, contezolid demonstrated a cumulative MIC percentage of 70% for VRE and 39.1% for E. faecalis (at MIC = 1 mg/L), whereas linezolid showed 0% and 1.1%, respectively. Among the 20 linezolid-resistant Enterococcus strains, all carried the optrA gene without 23S rRNA mutations. For contezolid, MICs were 4 mg/L for 19 strains and 2 mg/L for 1 strain. The ETEST, agar dilution and disc diffusion methods showed essential and categorical agreements of >90% for linezolid, with no major errors or very major errors. Contezolid demonstrated significant in vitro antibacterial activity against methicillin-resistant Staphylococcus, VRE and linezolid-resistant E. faecalis.

Antibiotic Susceptibility Pattern of Pseudomonas aeruginosa and Detection of Virulence Genes in a Tertiary Care Hospital, Kathmandu, Nepal

Pseudomonas aeruginosa is one of the most common causes of hospital-acquired infections. It threatens worldwide public health because of its intrinsic antibiotic resistance and virulence. In this context, this research aimed to determine the occurrence of P. aeruginosa in a clinical setting, examine its susceptibility to antibiotics, and detect the presence of virulence genes, viz. exoY, oprL and toxA in all isolates. It was a cross-sectional study carried out from June 2022 to December 2022. A total of 1356 clinical specimens were collected and processed in the laboratory for Gram staining, culture techniques, and biochemical tests. The Kirby-Bauer disk diffusion method was applied to examine the antibiotic susceptibility pattern and conventional PCR was used to detect the virulence genes in all confirmed P. aeruginosa isolates. 40.5% of specimens showed bacterial growth, of which only 3.02% were identified as P. aeruginosa. Among them, 61.0% were multidrug resistant and 29.2% were β-lactamase producers. Aztreonam (70.7%) was the most effective antibiotic. Among all P. aeruginosa isolates, 68.3% isolates were exoY positive, 61.0% were oprL positive and 56.1% were toxA positive. Strategic interventions are required to stop the emergence and spread of antimicrobial resistance as a result of the isolation of multidrug resistant (MDR) isolates carrying these virulence genes. This study can benefit the medical staff and the entire community in building a surveillance system and enhancing infection control procedures.

Synthesis, characterization, in-vitro and in-silico therapeutic studies of cinnamaldehyde derivatives

Cinnamomum verum (cinnamon) is a versatile spice belonging to the family Lauraceae. The plant is widely used for its various therapeutic potential viz. antimicrobial, antioxidant, anti-inflammatory, anti-diabetic, anticancer, etc. Its phytocompounds render these therapeutic efficacies of cinnamon. Cinnamaldehyde is the main active compound of cinnamon. Owing to the numerous pharmacology of cinnamaldehyde, cinnamaldehyde was procured from Himedia. Cinnamaldehyde Schiff bases were synthesized by refluxing (40–60 °C) cinnamaldehyde with different primary amines for 4–6 h. Glacial acetic acid was used as a catalyst. The product confirmation was done based on thin-layer chromatography. The derivatives were characterized and investigated for antimicrobial (disc-diffusion and broth-dilution methods), antioxidant (DPPH and ABTS assays), and cytotoxicity activities (SRB assay). Higher antibacterial activities were noticed with compounds, NS-6A (ZIsa = 13.7 ± 2.05 mm) and E.O.A (MICec, pa = 6.25 mg/mL) whereas the maximum antifungal results were observed with E.O.A (ZIfo = 13.1 ± 0.14 mm), MCA (MICao = 6.25 mg/mL) by. Compounds MCA (% RSADPPH = 85.35, % RSAABTS = 92.26), E.O.A (% RSADPPH = 83.81, % RSAABTS = 90.54) and NS-9A (% RSADPPH = 83.42, % RSAABTS = 90.32) showed highest antioxidant activity. The highest cytotoxicity against the HCT-116 cell line was observed in compounds MCA (IC50 = 0.27 µg/mL), and E.O.A (IC50 = 0.38 µg/mL). Compound NS-4A was observed with the highest docking score (-8.527). Conclusively, E.O.A, MCA, and NS-9A were the most potent compounds and need further in-depth exploration.

Uji Efektivitas Daya Hambat Ekstrak dan Perasan Lidah Buaya (Aloe barbadensis Miller) pada Bakteri Staphylococcus Aureus dengan Metode Difusi

Aloe vera is a plant that is rich in minerals, vitamins, and antibacterial properties. A study to analyze the antibacterial effectiveness of aloe vera in inhibiting the growth of Staphylococcus aureus bacteria isolated from acne pus. This study was an experimental laboratory study using the disc diffusion method, located at the Bacteriology Laboratory, Department of Medical Laboratory Technology, Poltekkes Kemenkes Surabaya, from February to May 2024. There were 6 sample treatments with 4 replications, 4 treatments of extract and juice concentration variations, namely concentrations of 70%, 80%, 90%, 100%, positive control using penicillin antibiotics, and negative control using clean distilled water. The results of this study show that at aloe vera extract concentrations of 70%, 80%, 90%, and 100%, the average diameter of the inhibition zone was 9 mm, 10 mm, 11 mm, and 12 mm, respectively, while in aloe vera juice, these concentrations did not form an inhibition zone. So it was concluded that aloe vera extract is more effective than aloe vera juice, the most successful test material to slow the growth of Staphylococcus aureus bacteria in this study was aloe vera extract with a concentration of 100%. This study also conducted qualitative phytochemical testing on aloe vera extract which has antibacterial compounds, namely saponins, tannins, flavonoids, and terpenoids. The results of the study on the effectiveness of the inhibitory power of aloe vera extract and juice against Staphylococcus aureus bacteria using the disc diffusion method were analyzed using quantitative descriptive and presented in tabulation form in the form of the diameter of the inhibition zone formed.

MODIFICATION OF GLASS IONOMER FILLING MATERIAL BY METAL NANOPARTICLES AND THEIR COMPOUNDS: EFFECT ON ANTI-MICROBIAL ACTIVITY

Background: Glass ionomer filling materials are widely used in stomatology, but do not have an antimicrobial effect that effectively prevents the development of secondary and recurrent dental caries. Researchers are attempting to modify these materials by introducing various biologically active additives into them. The aim of the study was to evaluate the antimicrobial properties of a dental ionomer filling material modified withadditives based on high–energy nanoparticles of silver, copper, titanium and their compounds. Material and methods: Colloidal aqueous and alcoholic solutions of metals and their oxides with stabilizers were obtained by the electroerosion method. Citric acid, cetylpyridinium chloride and Trilon B were used as stabilizers. The zeta potential and the distribution of particles of the dispersed phase in solutions were measured. Samples of dental glass ionomer cement "Cemion-Aqua" were impregnated with colloidal solutions of nanoparticles. The microbiological activity of glass ionomer fillings samples in relation to plaque was determined by disc diffusion and suspension methods. Results: The results showed that modification of glass ionomer cement samples with silver hydrosols in citric acid solutions with concentrations of 0.04% and 0.0025% increases the zone of radial lysis of microbial plaque colonies around the cement samples by 1.5 and 2.5 times compared with the control. By the suspension method, it was determined that silver hydrosols in a solution of citric acid and without it reduce the formation of colonies of microorganisms to several units up to 72 hours of exposure compared with the control. And copper hydrosols in solutions of cetylpyridinium chloride prevent an increase in the number of colonies of microorganisms after 24 hours of exposure compared with the control. Silver hydrosol in a solution of citric acid with a concentration of 0.0025% and silver alcohol sol reduce the number of colonies of microorganisms to several units after 3 hours of exposure.

Phytochemical Analysis and Nanoparticle Formulations of Extracts Myristica fragrans Houtt Leaves as Antibacterial

Myristica fragrans Houtt leaves contain secondary metabolites such as flavonoids, terpenoids and alkaloids, which have antibacterial properties. At the nanoscale, the particles have a bigger surface contact area, resulting in increased amounts and solubility of the active chemical. This leads to a stronger antibacterial activity. This study aims to examine the influence of several chitosan variations on particle size, antibacterial properties and the form of nanoparticles produced from Myristica fragrans leaves ethanol extract. Ethanol extract was analyzed using the UV-Vis spectrophotometric method to quantify total flavonoid content. Nanoparticles were synthesized using the ionic gelation technique with several ratios of chitosan and sodium tripolyphosphate, specifically 8:1, 10:1 and 12:1. Nanoparticles were analyzed with a Particle Size Analyzer (PSA) and Scanning Electron Microscopy (SEM). Agar diffusion test for bacteria germs using a paper backer. Myristica fragrans leaves ethanol extract was 50, 40 and 30 %, while nanoparticle extract was 5, 4 and 3 %. The overall flavonoid concentration in the QE/ethanol extract was 39.7252 ± 1.9596 mg. Antibacterial test results against Staphylococcus aureus and Escherichia coli bacteria and Myristica fragrans leaves extract limit inhibition area at 30 % (13.35 mm), 40 % (13.68 mm) and 50 % (13.93 mm) for Staphylococcus aureus and 30 (13.28), 40 (13.45) and 50 % (13.81 mm) for Escherichia coli. Myristica fragrans leaves extract chitosan nanoparticles included 3 (14.70), 4 (15.30) and 5 % (15.56 mm) for Staphylococcus aureus and 3 (14.60), 4 (14.65) and 5 % (15.05 mm) for Escherichia coli. Ionic gelation can create nanoparticles of Myristica fragrans leaves ethanol extract with chitosan and sodium tripolyphosphate. Myristica fragrans leaves nanoparticle ethanol extract exhibits better antibacterial activity than ethanol extract. Increasing chitosan concentration affects particle size. The ethanol extract of Myristica fragrans nanoparticle leaves showed slightly better antibacterial activity than the ethanol extract. HIGHLIGHTS Nanoparticles of extracts and extracts have proven excellent antibacterial activity against human pathogens through paper disc diffusion method. Antibacterial test results against Staphylococcus aureus and Escherichia coli bacteria and Myristica fragrans leaves extract limit inhibition area at 30 % (13.35 mm), 40 % (13.68 mm), and 50 % (13.93 mm) for Staphylococcus aureus and 30 % (13.28 mm), 40 % (13.45 mm), and 50 % (13.81 mm) for Escherichia coli. Myristica fragrans leaves extract chitosan nanoparticles included 3 % (14.70 mm), 4 % (15.30 mm), and 5 % (15.56 mm) for Staphylococcus aureus and 3 % (14.60 mm), 4 % (14.65 mm), and 5 % (15.05 mm) for Escherichia coli. The synthesized extract nanoparticles can be used against human pathogens acts as antibacterial drugs. GRAPHICAL ABSTRACT

Isolation and antimicrobial susceptibility profile of Salmonella species from slaughtered cattle carcasses and abattoir personnel at Dessie, municipality Abattoir, Northeast Ethiopia

BackgroundAntibiotic-resistant Salmonella is one of the main public health concerns in the world. Isolation of Salmonella in abattoirs has been considered the core source of infection in the community from meat. Still, there is limited information on the contamination rate of cattle carcasses.ObjectiveThis study aimed to document the occurrence and antimicrobial susceptibility profile of Salmonella species recovered from cattle carcass and abattoir personnel at Dessie, municipality abattoir, Northeast Ethiopia:MethodsA total of 336 carcass swabs of abdomen, neck, and hind limb from cattle carcasses and 24 stool samples were collected from abattoir personnel using a systematic sampling method from February to April 2019. The collected samples were transported using Cary-Blair transport media and cultivated on Selenite cysteine F-broth, Brilliant green agar, and Xylose-lysine deoxycholate agar plates to isolate Salmonella species. Gram stain, colony morphology, and biochemical tests were performed to identify the isolated bacteria. An antimicrobial susceptibility test for Salmonella was performed using the Kirby-Bauer Disc Diffusion method. Descriptive statistics; both bivariable and multivariable logistic regression analysis was performed using SPSS version 25 software. P-value < 0.05 at 95% CI was considered statistically significant.ResultsThe prevalence of salmonella species was 8%(27/336) from all samples.‘The prevalence of Salmonella isolates in cattle carcass and abattoir personnel was 8%(25/312) and 8.3%(2/24) respectively. The antimicrobial test showed that Salmonella species were 100% resistant to ampicillin, 59.3% to trimethoprim-sulfamethoxazole, 59.3% to tetracycline, and 55.6% to amoxicillin/clavulanate. From the total antimicrobial tested bacteria, 81.5%(22/27) were resistant to three and above classes of antibiotics (drug classes). Unwashed knives, carcasses, and hands of butchers during slaughtering were significantly associated (p < 0.05) with Salmonella found in carcasses.ConclusionsSalmonella isolation rates from cattle carcasses were high, with the bacteria showing notable resistance to most tested antibiotics. Poor hygiene practices, unsanitized equipment, and unhygienic beef processing were contributing factors.

ANTIBIOGRAM ASSAY OF E.COLI ISOLATES IN PATIENTS WITH URINARY TRACT INFECTION

Screening of prevalent bacterial pathogens for antibiotic susceptibility profiles in different regions is necessary. E. coli and other pathogens are so common in our environment that it is essential to monitor trends in antibiotic susceptibility regularly. Objective: The aim of the study was to find out the antibiotic susceptibility pattern of E.coli isolates in patients with urinary tract infection. Methods: This study was conducted at the Saidu Group of Teaching Hospital Swat after taking permission from the ethical committee of the institute. We collected a total of 900 urine samples from males and females of all ages for culture and sensitivity. The Kirby-Bauer disc diffusion method was used to assess the antibiogram on Mueller-Hinton agar. The plates were kept in incubator at 37°C for the 48 hours, and the inhibition zone was measured. The antibiogram was performed by Kirby-Bauer disc diffusion method applying various antibiotics. The bacterial strains were classified in to three majors groups on the basis of antibiotic susceptibility pattern resistant (R) sensitive (S), and intermediate (I). Data was statistically analyzed presented in the tables and figures. Results: For culture and sensitivity testing, a total of 900 urine samples from patients with suspected UTIs were obtained from the several departments' inpatient and outpatient to the microbiological lab. Substantial bacteriuria was noted in 250 (27.7%). The most prevalent bacteria isolated was E.coli (55%) and its antibiogram was carried out. Ampicillin had the highest proportion of resistance (96.1%), followed by Ceftriaxone (91%), Moxifloxacin (87.1%), and Ceftazidime (75.5%). Whereas it was sensitive to Fosfomycin (94.2%), followed by Sulzone ( 84.3%), Imepinem (84.3%) and Amikacin (78%). Conclusion: It was concluded from the current study that the most prevalent bacteria causing urinary tract infection was E.coli, and this bacteria showed remarkable resistance against Ampicillin Ceftriaxone, Moxifloxacin, and Ceftazidime. The most used bacterium antibiotics for therapy were Fosfomycin, Imepinem and Amikacin. Therefore, antibiotic susceptibility should be considered before therapy.

Antibiotic Resistance of Escherichia coli and Salmonella spp. Strains Isolated from Some Selected Poultry Farms in the Oforikrom Municipality Kumasi, Ghana

Antimicrobial resistance (AMR) is a serious worldwide issue that poses a significant risk to human and animal health. In this study, isolates of Salmonella spp. and Escherichia coli from poultry farms in the Kumasi Metropolis, Ghana, were evaluated for AMR prevalence and trends. Samples were gathered from different farms using cloacal swabs and surgical shoe covers. The resistance and susceptibility levels were assessed using the Kirby Bauer disk diffusion method. Twenty-four isolates of Salmonella spp. and E. coli were identified. The E. coli bacteria that were found were resistant to Ciprofloxacin, Tetracycline, Ampicillin, Cefotaxime, Co-trimoxazole, and Cefuroxime but susceptible to Gentamicin and Amikacin. The Salmonella strains that were identified were resistant to Cefuroxime, Tetracycline, Ampicillin, Ciprofloxacin, Cefotaxime, Co-Trimoxazole, and Gentamicin but susceptible to Amikacin, Ofloxacin, and Chloramphenicol. This study suggests broader research on antibiotic resistance in birds and educating poultry farmers about changing medication practices due to increasing pathogen resistance.

Green Synthesis of Chitosan-coated Tin Dioxide Nanoparticles Using Moringa oleifera Flower Extract Against Breast Cancer via the Caspase-dependent Apoptotic Pathway

Background and Purpose In the present work, chitosan is furnished with tin dioxide (CsSnO2) nanoparticles (NPs) synthesized using the green route using Moringa oleifera ( M. oleifera) flower extract. Methods These preparation methods are low-cost, easily reproducible, nontoxic, and eco-friendly. X-ray diffraction (XRD), dynamic light scattering (DLS), field emission scanning electron microscope (FESEM), energy dispersive X-ray, Fourier-transform infrared spectroscopy (FT-IR), and photoluminescence (PL) analysis were used to learn more about the CsSnO2 NPs. The antibacterial property of CsSnO2 NPs was assessed by the disc diffusion method against various pathogens. The MTT assay was done to assess the cytotoxicity of CsSnO2 NPs in MCF-7 cells. The expressions of the apoptotic proteins were examined using assay kits. Results XRD results demonstrated that the formulated CsSnO2 NPs exhibit a tetragonal structure. From the FT-IR spectra, the Sn–O stretching peak was observed at 579 cm–1. A FESEM image shows that the CsSnO2 NPs were formed into a spherical structure. Surface defects, such as tin and oxygen vacancies, are visible in the PL spectra, and the average particle size of CsSnO2 NPs is 32 nm. Thus, surface defects are essential parameters for biocidal properties. The antimicrobial property of CsSnO2 NPs and amoxicillin was investigated against bacteria and human fungal pathogens. CsSnO2 NPs exhibit similar antimicrobial properties as compared to amoxicillin. Also, the dosage of CsSnO2 NPs elevated their antimicrobial activity. The anticancer property of the green-synthesized CsSnO2 NPs against MCF-7 cells was further analyzed to study their ability to cytotoxicity and apoptosis induction, like caspase-3, -8, and -9 activation. Conclusion The study’s outcome revealed that the green synthesized CsSnO2 NPs are an outstanding candidate for cancer therapy.

Occurrence, Molecular Serogroups, Antimicrobial Susceptibility and Identification by MALDI-TOF MS of Listeria monocytogenes Isolated from RTE Meat Products in Southern Poland.

L. monocytogenes is considered one of the most dangerous foodborne pathogens. This study aimed to determine the occurrence of L. monocytogenes in RTE meat products from southern Poland, including serogroups and antimicrobial susceptibility, and to assess the usefulness of MALDI-TOF MS as a tool for identifying L. monocytogenes. A total of 848 production batches of RTE meat products were analyzed for L. monocytogenes. All L. monocytogenes isolates were serotyped using the multiplex PCR method, tested for antimicrobial susceptibility using the disk diffusion method and identified using the MALDI-TOF MS method. L. monocytogenes was detected in 52/848 batches of RTE meat products (6.13%). The isolates belonged to four serogroups: 17/52 (33%) isolates to IVb; 15/52 (29%) isolates to IIa; 10/52 (19%) isolates to IIc and 10/52 (19%) isolates to IIb. All isolates (52/52) showed susceptibility to the tested antimicrobials. Using MALDI-TOF MS, 10/52 isolates (19.2%) were identified at the level of secure genus identification, probable species identification; 37/52 isolates (71.2%) were identified at the level of probable genus identification; 3/52 isolates (5.8%) were incorrectly identified as L. innocua; and 2/52 isolates (3.8%) were not identified. The occurrence of L. monocytogenes in RTE meat products was low. Almost half of the analyzed isolates were L. monocytogenes of serogroups, which are most often associated with listeriosis in humans in Poland. All isolates showed susceptibility to five commonly used antimicrobials for treating listeriosis. The use of MALDI-TOF MS as a tool for the identification of L. monocytogenes indicated its limitations related to the insufficient representation of the pathogen in the reference database.

Antibiotic resistant Escherichia coli strains inhealthy pets from Tamaulipas, Mexico.

Antibiotic resistance constitutes a significant public health challenge, with diverse reservoirs of resistant bacteria playing pivotal roles in their dissemination. Among these reservoirs, pets are carrying antibiotic-resistant strains. The objective of this study was to assess the resistance profiles of Escherichia coli, and the prevalence of extended-spectrum β-lactamase (ESBL) producing E. coli strains in dogs and cats from Tamaulipas, Mexico. A total of 300 stool samples (150 dogs and 150 cats) from healthy pets were subjected to analysis. Antibiotic susceptibility testing and the identification of ESBLs were carried out by disc diffusion method. The presence of resistance genes, class 1, 2, and 3 integrons (intI1, intI2, and intI3) and phylogroups was determined by PCR analysis. The findings reveal that 42.6% (128/300) of the strains exhibited resistance to at least one of the eight antibiotics assessed, and 18.6% (56/300) demonstrated multidrug resistance (MDR), that distributed across 69 distinct resistance patterns. Altogether 2.6% of E. coli strains (8/300) were confirmed as TEM and CTX-M type ESBL producers. These outcomes underscore the roles of dogs and cats in Tamaulipas as reservoirs for the dissemination of MDR and/or ESBL strains. The results underscore the necessity for conducting prevalence studies on ESBL-producing E. coli, forming a foundation for comprehending the present scenario and formulating strategies for the control and mitigation of this issue.

Detection and characterization of multidrug resistant Escherichia coli carrying virulence gene isolated from broilers in Bangladesh.

The emergence and dissemination of multidrug resistant (MDR) bacteria pose a severe threat to public health by limiting clinical treatment and prophylactic options. This study investigates the prevalence of Escherichia coli in broilers, their phenotypic antimicrobial resistance (AMR) profiles and the presence of virulence-associated genes (VAGs) and antimicrobial resistance genes (ARGs) using polymerase chain reaction (PCR). A total of 216 pooled cloacal samples were collected from 1080 broilers across six districts of Bangladesh. Each pooled sample comprised randomly selected cloacal swabs from five birds per farm. E. coli isolates were identified using standard bacteriological approach, followed by biochemical assays and PCR. Antimicrobial susceptibility was assessed using the Kirby-Bauer disc diffusion method, and the presence of ARGs and VAGs was determined via PCR. Five selected isolates were partially sequenced for five VAGs using Sanger sequencing. A total of 177 E. coli isolates (81.94%, 95% confidence interval: 76.24%-86.53%) were identified. The isolates showed the highest resistance to ampicillin (93.79%), followed by tetracycline (91.53%), erythromycin (89.27%) and ciprofloxacin (87%). Conversely, ceftriaxone (80.79%) showed highest susceptibility, followed by gentamicin (37.29%) and neomycin (31.07%). All isolates were MDR, with a multiple antibiotic resistance indexes were <0.3. A significant percentage (16.38%) of E. coli isolates were MDR to five antimicrobial classes and harboured blaTEM, sul1, ere (A), tetA, tetB and tetC genes. The highest prevalent ARGs were blaTEM (88.14%) followed by ere (A) (83.62%) and sul 1 (72.32%). The prevalence of VAGs was astA (56.50%), iucD (31.07%), iss (21.47%), irp2 (15.82%) and cva/cvi (3.39%), respectively. This study highlights the presence of ARGs contributing to the development of MDR in E. coli carrying VAGs in broilers. Effective monitoring and surveillance of antimicrobial usage in poultry production systems are urgently required to prevent emergence and dissemination of AMR.

A comparative study of a rapid phenotypic antimicrobial susceptibility testing system directly from positive blood cultures to the disk diffusion and VITEK 2 methods

BackgroundSepsis is a life-threatening condition that impacts 49 million people annually and causes 11 million deaths worldwide. Surviving bloodstream infections (BSIs) depends on the rapid administration of effective antimicrobial treatment, underscoring a need for rapid antimicrobial susceptibility testing (AST). AimTo evaluate the performance of Quantamatrix's dRAST v2.5 system (Seoul, South Korea) for AST directly from positive blood cultures as compared to the Disk-Diffusion (DD) and VITEK 2 methods. MethodsThe study included 191 positive blood cultures from clinical samples and spiked blood culture bottles. Following Gram staining and species-level identification, AST was performed by VITEK 2 and standard DD methods using CLSI (2021) interpretation. ResultsdRAST demonstrated very good AST performance for a Gram-negative isolate, and good performance for Gram-positive isolates, meeting CLSI criteria for the acceptance of a new method. Antimicrobials that were not considered verified compared to VITEK 2 and DD were cefazolin, ceftazidime, meropenem, and trimethoprim/sulfamethoxazole for Gram-negatives and clindamycin, erythromycin, penicillin, and oxacillin for Gram-positives. dRAST ESBL detection results were strongly correlated with the ESBL phenotypes obtained with other methods. Additional resistance mechanisms were in concordance with traditional tests. ConclusionsdRAST demonstrated good AST performance, meeting CLSI criteria for most relevant antibiotics. dRAST was associated with a significant reduction in time-to-results, labor, and the subjectivity of result analyses, making it a valuable addition to efforts supporting the treatment of patients with bacteremia.AST (antimicrobial susceptibility test), blood culture, dRAST, rapid methods, sepsis, turnaround time (TAT).

Imipenem Susceptibility Pattern of Bacterial Isolates on Pregnant Women with Urinary Tract Infection in a Tertiary Hospital

Background: Urinary Tract Infection (UTI) in pregnancy, including Asymptomatic Bacteriuria (ASB) is associated with maternal morbidity and adverse pregnancy outcomes, like preterm birth and low birth weight. In spite of an association of ASB with adverse pregnancy results, screening and treatment is not done with much strength in our country. The antibiotic susceptibility patterns differ from region to region and in different global locations and are found to vary from time to time. This study was done to evaluate the susceptibility pattern of bacterial isolates against Imipenem causing UTI in pregnant women. Materials and methods: This observational study was conducted at the Department of Clinical Pathology, Bangabandhu Memorial Hospital, Chattogram During the period from January to June 2021. Urine sample from a total of 104 pregnant women was enrolled in this study. Isolation and identification of bacteria was done by conventional culture method and Imepenem susceptibility test, by Kirby-Bauer disc diffusion method. Results: Among the study samples, 31(29.8%) showed positive culture result and taken as confirmed UTI. E. coli (45.10%) was the predominant isolated bacteria followed by Klebsiella spp. (25.80%). 90% bacterial isolates were found sensitive to Imipenem and rest 10% were resistant. 93% E. coli showed sensitivity to Imipenem, whereas Klebsiella spp. showed 87.5% and Staphylococcus aureus showed 75% sensitivity to Imipenem. Both Enterococcus spp. and Pseudomonas spp. showed 100% sensitivity to Imipenem. Conclusion: Bacterial resistance against Imipenem is increasing day by day. So it should be kept as a reserve drug for severe life threatening condition. IAHS Medical Journal Vol 6(2), December 2023; 40-43

Extended-spectrum beta-lactamase (ESBL)- and non-ESBL producing Escherichia coli surveillance in surface water sources in Edo State, Nigeria: a public health concern

This research explores the antimicrobial resistance (AMR) profiles and prevalence of extended-spectrum beta-lactamase (ESBL) and non-ESBL-producing Escherichia coli in Ojerame Dam and Ovokoto Spring, Edo State, Nigeria. Over 12 months, water was systematically sampled to accommodate seasonal variations and analyzed by employing an ESBL-selective medium for bacterial species. Additionally, bacterial isolates underwent identification and characterization using polymerase chain reaction (PCR) and disk diffusion methods to evaluate their susceptibility to antimicrobials. Results indicated significant prevalence of ESBL-producing E. coli, which exhibited complete resistance to common antimicrobials like ceftriaxone, ceftazidime, cefotaxime, and ampicillin while demonstrating 100% sensitivity to ertapenem, imipenem, meropenem, and nitrofurantoin. Non-ESBL-producing E. coli were resistant to ampicillin but sensitive to other antimicrobials mentioned earlier. Furthermore, both ESBL and non-ESBL-producing E. coli displayed multidrug resistance to varying degrees. Specific ESBL genes, including blaTEM, blaCTX-M-1, and blaCTX-M-15, were identified, alongside resistance genes like tetA, tetM, sul1, sul2, sul3, qnrA, qnrB, and qnrS in E. coli. This study pioneers the documentation of ESBL-producing E. coli in surface water in the region. This signals impending health risks associated with water being a reservoir of resistant genes while emphasizing the urgency for further research and public awareness concerning the quality of surface water.

Determining the Phytochemical Properties and Antibiogram of Different Chewing Stick Plants on Selected Streptococcal Species Isolated from the Oral Cavity

Chewing sticks are small twigs obtained from plant stems, measuring 12-25cm long and tied in bundles of 5-10. These twigs have been used for oral hygiene for many years, even before the invention of toothpaste, mouthwash, and mouth sprays. This study aims to determine the phytochemical properties and antibiogram of different chewing stick plants on two streptococcal species isolated from the oral cavity. Streptococcus pyogenes and Streptococcus mutans were isolated from oral swabs of patients at Rivers State University Teaching Hospital and identified to the species level. The pure isolates were further tested against the antimicrobial effects of the aqueous and ethanolic extracts of four chewing stick plants: Vernonia amygdalina, Jatropha curcas, Massularia acuminate, and Phyllanthus mullerianus. Qualitative phytochemical screening and quantitative analysis were carried out on the plant stems to determine the presence of antimicrobials. The percentage of antimicrobials present in the plant stems ranged from 33.3% to 66.7%, with Jatropha curcas, Massularia acuminate, and Vernonia amygdalina exhibiting the highest percentages, and Phyllanthus mullerianus the lowest. The antibiogram of the isolates to conventional gram-positive antibiotics was determined by the disc diffusion method. Streptococcus pyogenes showed 75% sensitivity and 25% resistance to the antibiotics, while Streptococcus mutans displayed 50% sensitivity, 16.7% intermediate, and 33.3% resistance to the antibiotics. The investigation found that the ethanolic extract of Massularia acuminate has the highest zone of inhibition of 15.5 ±0.71mm at 100mg/ml, while Phyllanthus mullerianus exhibited the least inhibition at 8 ±0mm. The ethanolic extract of Jatropha curcas and Vernonia amygdalina showed little effect on the test isolates, with a range of 0-9.5±0.71mm. The aqueous extract ranged from 8±5.7 - 9.5±0.71mm at 100mg/ml, with Massulara acuminate exhibiting the highest and the lowest zones of inhibition. This finding indicates that Massularia accuminate has the ability to suppress the growth of dental plaque-forming Streptococcus mutans and Streptococcus pyogenes. Chewing sticks are more affordable and easily accessible, so they could be recommended in community oral health programs.

Incidence and Antibiotic Resistance Patterns of Staphylococcus aureus and Pseudomonas aeruginosa Isolated from Fomites in Critical Units of General Hospital Katsina

Study’s Excerpt Investigation of the role of fomites in the transmission of nosocomial pathogens, specifically Staphylococcus aureus and Pseudomonas aeruginosa, within various units of General Hospital Katsina was carried out. The results reveal high contamination of fomites in the male ward, with significant bacterial colony counts, and the differing susceptibility profiles of S. aureus and P. aeruginosa to commonly used antibiotics. There is need for improved infection control and antibiotic stewardship in the region. Full Abstract Nosocomial infections, predominantly caused by Staphylococcus aureus and Pseudomonas aeruginosa, continue to be a major public health challenge, especially in developing countries, due to their associated morbidity and mortality. This study aimed to isolate and identify bacterial pathogens from fomites in the Accident and Emergency (A&amp;E) unit, male ward, and female ward of General Hospital Katsina and to evaluate their antimicrobial susceptibility patterns. A total of 90 swab samples were collected from frequently touched items such as beddings, door handles, floor surfaces, scissors, and forceps across the three locations. Standard microbiological techniques were utilized for the isolation and identification of S. aureus and P. aeruginosa, followed by antibacterial susceptibility testing using the disc diffusion method. Bacterial growth was observed in 58 (64.4%) samples, with S. aureus accounting for 32 (55.2%) and P. aeruginosa for 26 (44.8%) of the isolates. The male ward exhibited the highest contamination levels, with a mean colony count of 725.25 CFU/plate, significantly higher than the female ward (487.67 CFU/plate) and the A&amp;E unit (48 CFU/plate), as confirmed by a one-way ANOVA (p &lt; 0.05). Chi-square analysis revealed no statistically significant association between bacterial species and hospital location (p = 0.823). The susceptibility testing showed that S. aureus isolates were generally susceptible to Gentamycin, Ciprofloxacin, and Pefloxacin but resistant to Amoxicillin. Conversely, P. aeruginosa displayed high resistance to Gentamycin and Septrin. Conclusively, these findings revealed the critical role of fomites in the transmission of pathogens and highlighted the need for enhanced infection control measures and targeted antibiotic stewardship programs to mitigate the risks associated with these infections.

Antioxidant, Antibacterial and Immunomodulatory Properties of Algerian Phoenix dactylifera

The aim of the current study is to evaluate the antioxidant, antibacterial, and phagocytic activities of the hydroethanolic extract of Phoenix dactylifera fruit variety Mech degla. The antioxidant activity was determined through DPPH assay, ferrous ions chelating assay, and CUPRAC assay. The antibacterial activity against four bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pneumoniae), was evaluated using the disc diffusion method, while the in vivo phagocytic activity was measured using carbon clearance method. The results showed that the extract exhibited good antioxidant activity with the IC50 values of 0.89 ± 0.3 g/l and 0.56 ± 0.24 g/l for DPPH and ferrous ions chelating activities, respectively, and the A0.5 value of 1.45 ± 0.15 g/l in the CUPRAC assay. Moreover, the extract showed notable antibacterial activity against all tested strains with the highest zone of inhibition (23.3 ± 0.3 mm) against S. pneumonia. Besides the extract did not show any significant toxicity, it was able to stimulate the phagocytic activity with a significantly faster carbon clearance rate at the dose of up to 100 mg/kg compared to the control group. Our results suggested that the Phoenix dactylifera fruit represents a promising source for the development of safe and effective immunomodulators as remedies to prevent and treat various microbial and immune-related diseases.

Design, characterizations, DFT, molecular docking and antibacterial studies of some complexes derived from 4-aminpantipyrine with glycine amino acid and ligand

The synthesis of the heterocyclic ligand (LK) involved the combination of 4-amino antipyrine, 4-nitroacetophenone, and glycine. A new series of transition metal complexes of Ni(II), Co(II), Cu(II), and Zn(II) have been synthesized from the Schiff base (LK). It was characterized by micro elemental analysis, FT-IR, UV-Vis, and 1H-NMR spectroscopy. The prepared complexes were characterized using (CHN) analysis, flame atomic absorption, as well as conductivity measurements and magnetic susceptibility. From the obtained data, the octahedral structure was suggested for all complexes. The ligand showed tridentate nature by binding to metal ions through the N atom of antipyrine and the N,O atom of glycine. The exhibited excellent electrolytic properties, except for the Cu(II) and Zn(II) complex which exhibited non-electrolytic behavior. Theoretical calculations with DFT were conducted for all complexes. The antibacterial activity of the ligand and its complexes against (S. aureus, B. subtilis) was evaluated through the disc diffusion method. Additionally, molecular docking analysis was conducted to gain more insights into the ligand's binding energy and interaction with the S. aureus receptor. KEY WORDS: 4-Amino antipyrine, Heterocyclic ligand, Glycine, Molecular docking Bull. Chem. Soc. Ethiop. 2024, 38(6), 1609-1624. DOI: https://dx.doi.org/10.4314/bcse.v38i6.9