Disc Diffusion Technique Research Articles

Phenotypic identification of Metallo-ß- lactamase resistance Gram negative bacteria from a clinical specimen in Sidama, Ethiopia.

Metallo-beta lactamase resistance is one of the carbapenem resistances that worsen the world nowadays. A new variant of carbapenem-resistant has only limited reports from Africa including Ethiopia. This study aimed to determine Metallo -ß- lactamase resistance Gram-negative bacteria in Hawassa University Comprehensive Specialized Hospital January-June 2023. A cross-sectional study was conducted in which consecutive patients infected with Gram-negative bacteria were included in the study. A structured questionnaire was used to collect the data with oriented nurses if the patients/or caregivers gave consent to participate in the study. Clinical specimens are processed based on the standard operating procedure of the Microbiology laboratory and Clinical laboratory standard institute guidelines. Culture and sensitivity testing was used to isolate the bacteria. Gram staining and biochemical tests was used to identify the bacteria to genus and species. Kirby disc diffusion technique was used to determine the susceptibility of antibiotics. Statistical Software for Social Science (SPSS) version 21 is used for data entry and analysis. Descriptive statistics and logistic regression were used to interpret the data. The odds ratio at 95% confidence interval (CI) and p-value < 0.05 were taken as a statistically significant association. Our study included 153 isolates from different specimens, 83 (54.2%) were from male patients and 70 (45.8%) were from females. Klebsiella pneumonia was the predominant 43, followed by Escherichia coli 32, Acinetobacter spp 25, Pseudomonas spp 15, Enterobacter agglomerus 9, Klebsiella ozaenae 6, Enterobacter cloacae 5, Klebsiella oxytoca 4, (Klebsiella rhinoscleromatis, Proteus mirabilis and Morganella morganii) 3, Providencia stuartii 2 and (Citrobacter spp & Proteus vulgaris) 1. The rates of multi, extensive and pan-drug resistance bacteria accounted for 128/153 (83.7%), 77 /153(50.3%), and 26/153 (17.0%), respectively. Carbapenem resistance was 21 (13.7%), of this 7.2% were Enterobacteriaceae, 5.2% were Acetinobacter spp. and 1.3% Pseudomonas spp. Metallo-beta-lactamase was 17 (11.1%), of this, Enterobacteriaceae were 9(5.9%), Acetinobacter spp. 7(4.6%), and Pseudomonas spp. 1(0.7%). There were no variables statistically significantly associated with metallo-beta-lactamase-resistant. Our study revealed that Metallo-beta-lactamase resistance was circulating in the study area. There was a high rate of carbapenem resistance, multi, extensive and pan-drug resistance. Therefore, a measure should be taken to alleviate the emerging threat that leaves the patients without the option of treatment.

Antibiotic Susceptibility Pattern of Escherichia Coli at Tertiary Care Hospital, Islamabad

Objective: The objectives of this study are; 1. To comprehensively investigate the antibiotic susceptibility pattern of Escherichia coli, focusing on its virulence factors to understand its pathogenicity and address the challenges posed by antibiotic resistance. 2. To assess the prevalence of citrate and TSI in E. coli isolated from urine to evaluate the impact of antibiotics according to Clinical and Laboratory Standards Institute (CLSI 2023) guidelines. Study Design: Cross-sectional study. Study Place: Tertiary Care Hospital, Al Nafees Medical Hospital, Islamabad, Pakistan. Study Duration: March 2023 to October 2023. Methodology: Informed consent was obtained from the microbiology lab of Al Nafees Medical College. The study utilized biochemical tests, including citrate and TSI, for identification and differentiation of E. coli based on metabolic characteristics. A total of 50 urine samples were collected for isolation and identification of E. coli. The Kirby-Bauer disc diffusion technique was employed to determine antibiotic susceptibility, identifying nitrofurantoin and Fosfomycin as the most effective choices for bacterial infections. Results: Antibiotic efficacy assessments revealed nitrofurantoin as notably effective, surpassing other antibiotics according to CLSI guidelines. In contrast, ciprofloxacin demonstrated the lowest efficacy among the tested antibiotics. The research highlights the importance of judicious antibiotic selection for optimal therapeutic outcomes in clinical settings, emphasizing the need for continuous monitoring and optimization of antibiotic treatment strategies.

Phytochemical Analysis, Antibacterial Activity, and GC-MS Characterization of Methanolic Extract of Azadirachta indica from Nuwakot, Nepal

Azadirachta indica, known as Neem, is renowned for its diverse pharmacological properties. The present work was carried out to examine the bio-efficacy of the leaves of Azadirachta indica by examining phytochemical screening, GC-MS analysis, and antibacterial properties. Phytochemical screening of the extract revealed the presence of bioactive secondary metabolites like alkaloids, carbohydrates, flavonoids, tannins, steroids, and phenolic compounds. The GC-MS analysis revealed the presence of 30 compounds, among which 3- Oxatricyclo[20.8.0.0(7,16)triaconta-1(22),7(16),9,13,23,29-hexene, Phytol, 9,12,15-Octadecatrien- 1-ol, (Z, Z, Z), 3E,5E,7E-6-methyl-8-(2,6,6-trimethyl-1-cyclohexenyl)-3,5,7-octatrien-2-one, n- Hexadecanoic acid, dl-alpha,-Tocopherol, and Hexanedioic acid were found as major compounds. The antibacterial activity of the Azadirachta indica was evaluated against the Gram-positive bacterium Bacillus subtilis and the Gram-negative bacterium Enterobacter aerogenes using the filter disc diffusion technique on the Muller Hilton Agar plate (MHA). A significant zone of inhibition of 7 mm and 11 mm was observed, indicating the extract’s efficacy against both Gram-positive and Gram-negative bacteria. These findings underscore the potential of Azadirachta indica from Nuwakot district Nepal, as a source of natural bioactive compounds.

Evaluation of the antimicrobial activities of Napoleona imperialis leaf extracts against multi-drug resistant bacterial isolates from diabetic foot ulcer

Background: The increased resistance of Gram-negative bacteria, particularly those that produce extended beta-lactamase, are limiting the efficacy of antimicrobial drugs in treating infected diabetic foot ulcers. This study evaluates antimicrobial activities of Napoleona imperialis leaf extracts on bacterial isolates of diabetic foot ulcers as a way of developing novel antimicrobials that will be effective in treating infections caused by multi-drug-resistant (MDR) bacterial isolates. Methodology: Fresh leaves of N. imperialis were collected and identified by a plant taxonomist at the Department of Plant Biology and Biotechnology, Nnamdi Azikiwe University, Awka, Nigeria. The leaves were washed and air- dried under shade and pulverized into fine powder using local milling machine. The pulverized plant was extracted using methanol, hexane, ethyl-acetate, and water. The test organisms used were MDR bacteria isolated from fresh clinical samples collected from patients with diabetic ulcer. The samples were processed using conventional cultures, biochemical identification and molecular detection by PCR methods, and antimicrobial susceptibility testing was done by the disc diffusion technique. The phytochemical compositions of the extract were assessed using standard methods. Antibacterial activity of the extracts was performed at a concentration of 400mg/ml of the extracts using agar well diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MIC) of the extracts were determined using serial (doubling) dilution technique. The time-kill assay of the plant extract was also evaluated. Results: The MDR isolates recovered from the diabetic ulcer were Escherichia coli, Klebsiella pneumoniae, Streptococcus pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. The plant extract yield showed that aqueous fraction of the leaf extract gave higher yield of 37.3%, followed by ethyl acetate fraction of the leaf extract at 26.8%, hexane fraction of the leaf extract at 22.3%, and the least was crude methanol leaf extract at 13.4%. The phytochemical analysis showed that the leaf extracts contained phenols, flavonoid, tannins, glycosides, alkaloids, saponin, terpenoids and triterpenes. The methanol extract produced highest mean inhibition zone diameter of 19.7±00mm against E. coli, 19.3±1.2mm against P. aeruginosa, 19.3±1.2mm against S. pneumoniae, 18.7±1.2mm against S. aureus and 17.7±1.5mm against K. pneumoniae. The bacteriostatic (MIC) activities of this methanol extract at different concentrations ranged from 3.125 to 25.00mg/ml, and bactericidal (MBC) activities ranged from 6.25 to 50.00mg/ml. The time- kill assay of the crude methanol leaf extract at 1xMIC, 2xMIC and 3x MIC showed a decrease in the number of viable cells count of the initial inoculum within 2-8 hours of incubation, indicating high activity. Conclusion: The methanol leaf extracts of N. imperialis could be used as a complementary source of antimicrobials to the conventional antibiotic in the treatment of wound infections caused by MDR bacteria due to the contents of essential secondary metabolites in the plant extract and the antibacterial activities observed.

Evaluation of invitro antimicrobial activity of Nauclea latifolia root extracts against multi-drug resistant bacterial isolates from diabetic foot ulcers

Background: Infections caused by multi-drug resistant organisms (MDROs) are becoming global health crisis especially the extended-spectrum beta-lactamase (ESBL) producing microbes. The trend in the occurrence of MDROs has been considered by the World Health Organization as critical and urgent need facing medical science. Herbal plants containing phytochemicals that can be synthesized into new antimicrobial agents are potential alternatives for therapy of MDROs. Methodology: Fresh roots of Nauclea latifolia were harvested from the shrub and identified by botanist at the Nnamdi Azikiwe University with specimen number NAUH-215A. The roots were washed, chopped into smaller sizes for easy drying, air dried under shade and pulverized using a milling machine. The pulverized plant root was extracted using methanol, hexane, ethyl-acetate, and aqueous extraction. Wound swabs were collected from diabetic patients with foot ulcers and processed using conventional culture isolation and biochemical identification test scheme for bacterial isolates that were used as test organisms. Antimicrobial susceptibility test (AST) was performed by the Kirby-Bauer disc diffusion technique and multi-drug resistance (MDR) was determined for each isolate. The phytochemical composition of the plant extracts was assessed using standard methods. Antibacterial activities of the methanol root extracts and the fractions were determined at a concentration of 400mg/ml using agar well diffusion method in triplicate and the mean zone diameter of inhibition measured. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the methanol root extracts and the fractions were determined using the serial doubling dilution technique. The time-kill assay was also evaluated. Results: The root extract yield of N. latifolia indicated that methanol extract produced a higher yield of 12.8%, followed by ethyl acetate root fraction at 8.0%, hexane fraction at 7.6%, and aqueous extract produced the least yield at 6.8%. The phytochemical analysis showed that methanol root extracts contain various phytochemicals which included phenols, flavonoids, tannins, glycosides, alkaloids, saponins, terpenoids, and triterpenes. The methanol root extract produced a higher mean inhibition zone diameter of 25.0±00mm against Escherichia coli, followed by mean inhibition zone diameter of 23.0±1.0mm against Klebsiella pneumoniae, 20.0±2.0mm against Staphylococcus aureus and Streptococcus pneumoniae, and the least mean inhibition zone diameter of 18.7±1.2mm against Pseudomonas aeruginosa. The MIC of the methanol root extracts for N. latifolia ranged from 3.125 to 12.5mg/ml, and MBC ranged from 6.25 to 25.00 mg/ml. The time-kill assay of methanol extract at 1x MIC, 2x MIC, and 3x MIC showed that reduction in the viable cell count of the initial inoculum was observed within 2-8 hours of incubation at 37oC, indicating high activity. Conclusion: The methanol root extracts of N. latifolia could be a potential source of antibacterial agent, which can complement conventional antibiotics currently used in the treatment of infections caused by MDR bacterial isolates.

Nutritional value, HPLC-DAD analysis and biological activities of Ceratonia siliqua L. pulp based on in vitro and in silico studies

The phytochemical, nutritional, and biological features of wild carob pulp from Tanzight (TN), Ait-Waada (AW), and Tizi-ghnayn (TG) in Azilal were studied. The results of the study reveal that the carob pulp examined has a low-fat level. AW had the most total sugar (78.34 ± 3.00%), total reducing sugar (27.20 ± 2.89%), crude fiber (14.21 ± 1.23%), sucrose (24.303 ± 0.038%), sodium (153.7 ± 18.52 mg/kg), pH (5.599 ± 0.05), and total polyphenol content (4134.50 ± 17.91 mg GAE/100 g DW). TG has higher amounts of potassium (11373 ± 153.7 mg/kg), calcium (4345 ± 7.211 mg/kg), phosphorus (3551 ± 175.1 mg/kg), magnesium (1347 ± 52.43 mg/kg), fructose (7.635 ± 0.012%), and total flavonoids (1678.08 ± 24.05 mg RE/100 g DW). TN has the highest levels of crude protein (5.607 ± 0.047%), moisture (9.33 ± 0.57%), ash (4.16 ± 0.02%), glucose (2.956 ± 0.047%), and total condensed tannins (529.61 ± 6.76 mg CE/100 g DW). The ethanol extract derived from AW exhibited noteworthy antioxidant activity, as evidenced by its total antioxidant capacity (TAC) of 1245.83 ± 26.33 µg ascorbic acid equivalent /mg extract and IC50 values of 18.45 ± 1.41 µg/mL, 124.98 ± 5.21 µg/mL, and 24.87 ± 1.30 µmol/mL for 2,2-Diphenyl-1-picrylhydrazil (DPPH), beta carotene (β-Carotene), and 2,2’-azino-bis (3-éthylbenzothiazoline-6-sulfonate) (ABTS), respectively. Furthermore, AW has demonstrated significant antibacterial activity against a variety of bacterial and fungal strains using disc diffusion and broth dilution techniques. The analysed samples also demonstrated encouraging anti-cancer effects on MDA-MB-231, MDA-MB-436, and MCF-7 cancer cell lines. The biological activities were confirmed through molecular docking analysis, identifying naringin and quercetin 3-O-β-glucoside as related compounds. Additionally, ADME analyses have revealed that all the synthetic compounds examined in this study demonstrate high intestinal absorption, meet Lipinski’s criteria, indicating their potential suitability for oral drug development. Based on these findings, wild carob pulp from Azilal province may contain bioactive compounds and nutrients.

Efficacy of lactic acid and acetic acid against multidrug resistant Staphylococcus aureus, E. coli and klebsiella sp.

In the phase of emerging antibiotic resistance, the efficacy of organic acids including lactic acid and acetic acid proved worth applicable. The rational use of antibiotics has always been challenging. The overuse and under-use of antimicrobials provokes the development of resistance, through which multidrug Resistant (MDR) strains have emerged. In this experiment we trialed MDR strains of Staphylococcus aureus, Escherichia. coli and Klebsiella sp. recovered from clinical cases of mastitis through broth dilution method followed by disc diffusion technique to demonstrate the minimum inhibitory concentration (MIC) and minimum bacteriocidal concentration (MBC) for lactic and acetic acids. For lactic acid the MIC for Staphylococcus aureus, E. coli and Klebsiella sp. was 0.78µl, 0.39µl and 0.39µl respectively at the 0.5 McFarland turbidity standard. The zone of inhibition (ZOI) was ranging from 18mm±1 to 20mm±1 in diameter. However, the acetic acid MIC of 0.78µl was found equally effective against all test bacterial spp. with ZOI of 18mm±1 to 19mm±1 in diameter. Moreover, the MBC for lactic acid was 1.56ul against Staphylococcus, 0.78ul for E. coli and Klebsiella spp. exhibiting the ZOI ranging from 20mm±1 to 22mm ±1 in diameter. Acetic acid revealed the MBC of 1.56ul against all test bacterial spp. having ZOI ranging from 19mm±1 to 22mm±1 in diameter.

Isolation and Molecular Detection of Bacteria from Frequently Touched Objects of Various Public Places at Sadar Upazila of Mymensingh District

The current research was conducted to investigate the magnitude of bacterial contamination in public buses, different wards of hospitals, and public toilets of bus stations and hospitals in Sadar Upazila, Mymensingh, Bangladesh. A total of 90 swab samples were collected aseptically from the most frequently touched surfaces of the sample area. Identification of the isolated bacteria was done by staining and biochemical tests, followed by molecular detection by PCR using genus or speciesspecific primers. Isolated organisms were then subjected to an antibiotic sensitivity test using disk diffusion techniques using 13 commonly available antibiotics. Among the samples, 76.67% (n=69/90) were positive for E. coli, 80% (n=72/90) were positive for Klebsiella spp., and 68% (n=61/90) were positive for Staphylococcus spp. Positive tetA and stx-1 genes were found in 40 and 19 E. coli isolates, respectively. 23 positive mecA genes, or MRSA, were found in Staphylococcus aureus isolates that pose a threat to public health. Toilets of the bus stations were the most contaminated place by the selected bacteria, with the prevalence of E. coli,Klebsiella spp., and Staphylococcus aureus being 81.48% (n=22/27), 77.78% (n=21/27), and 81.48% (n=22/27), respectively. In an antibiogram study, E. coli isolates showed 100% resistance against amoxicillin, azithromycin, tetracycline, and co-trimoxazole. Klebsiella spp. was revealed to be 100% resistant to amoxicillin, followed by colistin sulfate (60%). Staphylococcus aureus isolates were 100% resistant to methicillin, cefoxitin, and cefixime. The findings can be used to raise public awareness about the possible threat, hence preventing the spread of infectious disease in public places. J. of Sci. and Tech. Res. 6(1): 125-137, 2024

Antibacterial Activity of Chitosan, Trisodium Citrate and Acetic Acid Against Staphylococcus Aureus Bacteria Isolated From Raw Milk In Baghdad City

Staphylococcus aureus bacteria is cause of dangerous food poisoning through contamination of raw milk; therefore, this study aimed to determine the prevalence of S. aureus in raw milk sold in local markets of Baghdad city and the antibacterial activity of chitosan, trisodium citrate and acetic acid against the pathogenic bacteria, the antibacterial susceptibility profile of isolates was performed by using (13) antibacterial agents using Kirby–Bauer disc diffusion technique. the results showed that (3) samples out of 25 samples (12%) were isolated from raw milk, all isolates were positive to the experimental tests characterized as S. aureus depending on the cultural, biochemical, serological and molecular examinations. The PCR technique used to verify the positive isolates by targeting the (nuc) gene, the molecular size (181 bp), the antibacterial activity was done by broth and agar dilution method with detection the bacterial counts. the Initial counting (mean) log CFU/ ml of isolates was 4.623 CFU/ml. The minimum inhibitory concentration of chitosan and acetic acid against Staphylococcus aureus by macro-broth dilution method was 20and 1,25 mg /ml respectively, while trisodium citrate had no inhibitory activity against the exanimated bacteria. The antibiotic susceptibility profile for positive isolates showed that all isolates were resistant to (ampicillin, methicillin, Cefixime and Cefoxitin),in conclusion comparing the effects of the three antibacterial agents against S. aureus causes contamination of cow raw milk sold in Baghdad city, 1.25 mg/ml of the acetic acid was found effective with higher antibacterial activity, followed by chitosan 2 mg /ml, while trisodium citrate showed no antibacterial effect.

ANALYSIS OF ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS IN A TERTIARY CARE HOSPITAL

Objective: The present study aimed to evaluate MRSA prevalence among Staphylococcus aureus isolates, identify demographic factors associated with infections, and evaluate susceptibility to various antibiotics. Material and Methods: The study involved various clinically infectious samples. S. aureus was identified using a battery of tests and MRSA was identified utilizing the cefoxitin disk diffusion technique. At the same time, adherence to Clinical and Laboratory Standards Institute protocols guided the execution of the antibiotic susceptibility assay. Results: Out of 28,239 culture samples, 569 S. aureus isolates were detected, with 308 (54.1%) being MRSA. Most samples originated from individuals aged 41–60 years (n=110, 36%), and males accounted for (n=205, 67%) of the isolates. Pus samples notably yielded the highest proportion of MRSA (n=249, 80.8%), primarily from the surgery ward (n=120, 38.9%). Remarkably, the strains demonstrated substantial sensitivity (&gt;90%) to linezolid, vancomycin, chloramphenicol, and doxycycline. Conclusion: In summary, MRSA strains were sensitive to drugs such as linezolid, vancomycin, chloramphenicol, and doxycycline. The emergence of resistant variants emphasizes the necessity for continuous surveillance and careful antibiotic use, informing antibiotic stewardship programs and clinical strategies for managing MRSA infections in health-care settings.

Uji Aktivitas Antibakteri dan Antioksidan dari Metabolit Ekstraseluler Bakteri Endofit Tumbuhan Mahang (Macaranga bancana)

The increasing pollution which promotes accumulation of free radicals and a significant number of bacterial resistances to antibiotics have prompted various efforts to search for new sources of bioactive compounds. The aim of this study was to investigate the antibacterial and antioxidant properties of bioactive compounds produced by endophyte bacteria from M. bancana. The most potential bacterial isolate was extracted its active constituents until obatined crude extract and tested using disc diffusion technique and detemined MIC and MBC values. Antioxidant properties using DPPH radicals were performed followed by GC-MS analysis of its crude extract. We obtained that MB3.1 isolate exhibited antibacterial activity against all four tested bacteria including Escherichia coli strain ATCC 8739, Pseudomonas aeruginosa strain ATCC 9027, Staphylococcus aureus strain ATCC 25923, and Bacillus subtilis strain ATCC 6633. The best MIC values of this extract were shown against B. subtilis with an MIC value of 39.06 μg/ml. Further, MB3.1 extract showed a moderate antioxidant activity with an IC50 value of 248.19 μg/ml. GC-MS analysis of MB3.1 extract revealed 10 dominant compounds, including phenylethyl alcohol, benzeneethanol, 4-hydroxy, and tryptophol, which might be responsible for the antibacterial and antioxidant properties.

Plasmid Profile and Curing of Multiple Antibiotic Resistant Escherichia coli Isolated from Straw Colored Fruit Bats (Eidolon helvum )

Plasmids are well recognized to play vital roles in developing and spreading multi-drug resistance in bacteria, which pose a risk to veterinary and human health. Six multi-drug-resistant Escherichia coli were gotten from Eidolon helvum from Osun State, Nigeria. Analytical Profile Index (API) 20E kit for biochemical identification was used to confirm the identity of the isolates. Antibiotic susceptibility test using eleven different antibiotics was performed using Kirby-Bauer’s disc diffusion technique. The Escherichia coli was analyzed for their plasmids, and plasmid curing was done using ethidium bromide and sodium dodecyl sulphate. The results of the API 20E kits confirmed the isolates to be Escherichia coli. They were 100% resistant to ampicillin, augmentin, ceftazidime, cefuroxime, ertapenem, sulfamethoxazole, and cefixime and were also 100% susceptible to gentamicin, ciprofloxacin, ofloxacin, and nitrofurantoin before and after curing. Plasmid analysis revealed that all the isolates except one had plasmid. The plasmid molecular weight ranged from 9.961(kpb) to 9.369 (kpb) for the untreated isolates. while isolates treated with sodium dodecyl sulphate and ethidium bromide still had bands but with reduced molecular weight, ranging from 8.369 (kpb) to 8.462 (kpb) and 8.369 (kpb) to 8.574 (kpb) respectively. The exhibition of the same susceptibility pattern before and after curing the plasmid present in the Escherichia coli from Eidolon helvum studied suggests that they are chromosomally mediated, indicating that resistance can occur naturally in nature. Also, the results of the curing agents indicated that sodium dodecyl sulphate is a better curing agent than ethidium bromide.

Phytochemical analysis of Bienertia sinuspersici extract and its antioxidant and antimicrobial activities

Abstract Natural products derived from plants are emerging as a valuable resource for a range of antimicrobial agents in sustainable agriculture. The current work looks for the first time at the antimicrobial properties of a methanolic extract of Bienertia sinuspersici against phytopathogenic microorganisms in vitro, using disk diffusion and food poisoning techniques. The phytochemical analysis revealed the presence of total phenols, flavonoids, and antioxidant activity measured at 34.2, 20.6, and 20.1 mg/g, respectively. Furthermore, the concentrations of tannins, saponins, and alkaloids were documented at 17.6, 9.8, and 3.2 mg/g, respectively. The high-performance liquid chromatography examination of polyphenolic chemicals revealed that gallic acid was the most abundant compound at 2.22 mg/g, whereas methyl gallate was the least abundant at 0.021 mg/g. Gas chromatography–mass spectrometry analysis revealed that the primary components were oleic acid, n-hexadecanoic acid, and methyl ester of 11-octadecenoic acid. The extract had a maximal inhibitory percentage of 57.8% against Fusarium oxysporum at 300 µg/mL, 60.4% against Rhizoctonia solani at 500 µg/mL, and 88.2% against Botrytis cinerea. On the other hand, the extract demonstrated inhibition of Pectobacterium atrosepticum growth by 10.67 mm at a concentration of 100 µg/mL, while Ralstonia solanacearum was inhibited by 9.76 mm and Pectobacterium carotovorum by 9 mm. Overall, the extract of B. sinuspersici demonstrated promising efficacy as antibacterial and antifungal agents against different plant pathogens. Therefore, it could offer a sustainable and environmentally friendly alternative for managing plant diseases.

Chemical constituents and antibacterial activities of Cameroonian dark brown propolis against potential biofilm-forming bacteria

Propolis is a resinous material collected by different bee species from various plant exudates and used to seal holes in honeycombs, smoothen the internal walls, embalm intruders, improve health and prevent diseases. From its n-hexane extract, eight compounds were isolated and characterised as: mangiferonic acid (1); 1-hydroxymangiferonic acid (2), new natural product; mangiferolic acid(3); 27-hydroxymangiferolic acid (4), reported here for the first time as propolis constituent; 27-hydroxymangiferonic acid (5); α-amyrin (6); β-amyrin (7) and lupeol (8). The chemical structures of the isolated compounds were elucidated using spectroscopic methods, such as 1D and 2D-NMR, mass spectrometry and comparison with previous published reports. Compounds 6-8 and n-hexane extract were tested against Gram-negative and Gram-positive bacteria strains using agar disc diffusion and macrodilution techniques. Interestingly, n-hexane extract and compounds 6-8 had good inhibitory activities against Methicillin Resistant Staphylococcus aureus (MRSA) and the clinical Klebsiella pneumoniae isolates. The biological effects of n-hexane extract and its fraction against K. pneumoniae 12 CM and MRSA revealed in the present study suggest that the Cameroonian dark brown propolis could be a potential alternative management of biofilms on medical devices and respiratory skin or infections.

Pluronic F-127 coated zinc oxide nanoparticles from Gynura pseudochina: a comprehensive assessment of antibacterial, and anticancer activities

The study synthesized Pluronic F-127 coated zinc oxide nanoparticles (PF-127ZnO NPs) using Gynura pseudochina leaf extract and evaluated their antibacterial, antioxidant, and anticancer properties using various characterization methods such as UV–Vis, Fourier Transform Infra-Red, Photoluminescence spectroscopy, FESEM, EDAX, TEM, SAED, XRD, and DLS. The disc diffusion technique was used to evaluate the antibacterial properties of synthesized Pluronic F-127 coated zinc oxide nanoparticles against various pathogens and significant anticancer activity was noticed. The study examined the cytotoxicity of PF127ZnO nanoparticles to Hep3B cells in vitro. The cytotoxicity was IC50 at 10 µM concentration. The study examined the biocompatibility of PF-127ZnO NPs, revealing membrane blebbing, chromatin condensation, and stimulation of the proapoptotic protein caspase cascade family. The study reveals that PF-127ZnO NPs, synthesized from G. pseudochina leaf extract, exhibit antibacterial and antihepatic properties, offering potential biomedical applications due to their high stability and biocompatibility.

Guardians of resistance and virulence: detection of mec, femA, Van, pvl, hlg and spa genes in methicillin and vancomycin-resistant Staphylococcus aureus from clinical and food samples in Southwestern Nigeria.

Staphylococcus aureus strains are highly virulent and associated with an eclectic range of severe nosocomial and community-acquired infections. This study assessed methicillin- and vancomycin-resistant Staphylococcus aureus (MRSA/VRSA) from clinical and ready-to-eat (RTE) food sources, screened for antibiotic resistance; and molecular determinants of antibiotic and virulence genes. Altogether, 465 clinical and RTE food samples were analyzed via conventional microbiological techniques and S. aureus identification was confirmed by nuc gene detection. Phenotypic screening for methicillin and vancomycin-resistance was by agar-screen cum micro-broth dilution respectively, while antibiotic susceptibility testing was done by the disc-diffusion technique. VanA/vanB/VanC1, femA, mecA/mecC; pvl/hlg and spa gene detection was via Polymerase chain reaction. Phenotypically, 211 Staphylococcal isolates were recovered, 138 (65.4%) of them carrying the nuc gene - all 138 (100.0%) were VRSA, while 59/138 (42.8%) were MRSA phenotypically. Overall, 114/138 (82.6%), 7/138 (5.1%), and 6/138 (4.3%) of isolates had the femA, mecA, and mecC genes, while van genes were detected in only 3 (2.2%) isolates, with virulence determinants pvl, hlg, and spa gene carriage in 8 (5.8%), 10 (7.2%), and 77 (55.8%) isolates respectively. In all, 11.6% carried resistance-associated genes, 55.8% carried virulence genes, and co-detection of resistance and virulence genes was observed in 12.3%. Overall, 96/138 (69.6%) were multidrug-resistant (MDR), while one strain was extremely drug-resistant (XDR). MAR Indices ≥ 0.2 was observed in 83.3% of isolates. This study highlights virulence levels of MRSA and VRSA circulating strains in Osogbo, contributing to their sustained surveillance, and improving available data for successive epidemiology investigations. This study also reports the occurrence of the mecC gene in S. aureus isolates from RTE foods and human samples in Southwestern Nigeria.

Detection and molecular insights into the azurin gene expression post- gamma irradiation in P. aeruginosa.

Azurin, a secondary metabolite from Pseudomonas aeruginosa, has attracted much attention owing to its valuable therapeutic and biological applications. This work aimed to study and chartly maximize the azurin production process using different doses of gamma irradiation (5-400Gy) in P. aeruginosa isolates. Seventy-six P. aeruginosa isolates were sourced from 135 environmental samples and 35 clinical bacterial isolates with the following descending order: 35 isolates (46%) from clinical samples, 26 isolates (34%) from water samples, and 15 isolates (20%) from soil samples. The disc diffusion technique was used for antimicrobial susceptibility testing, revealing that the multidrug-resistant (MDR) rate among all collected isolates according to the criteria determined by Clinical and Laboratory Standards Institute (CLSI) was 54 (71%). The genomic experimental results revealed that only 37 MDR isolates tested positive for the azurin gene, as detected by the PCR product at 446bp. These findings were further supported by FTIR analysis, which revealed peaks around 1636.96cm- 1, indicating a prominent α-helix secondary structure of azurin in these isolates. Related to their pathogenicity and antibiotic resistance, isolates from clinical origin exhibited the higher azurin gene expression level. Besides, this study confirmed the potency of gamma radiation exposure at 50 and 100Gy significantly increased the azurin expression levels in three tested clinical isolates (P ≤ 0.05), with a maximum fold expression level of 63.55 compared to the non-irradiated samples. In conclusion, low doses of gamma irradiation effectively enhanced expression level of a secondary metabolite azurin, providing a considerable benefit for subsequent purification processes in both biological and medical applications.

Microbial profile and associated factors of external ocular bacterial and fungal infections in Arba Minch General Hospital: a cross-sectional study

External ocular infections are of serious global concern, which cause significant visual morbidity and even blindness, particularly in low-income and resource-limited countries. Herewith, we are reporting the profile of bacteria and fungi causing external ocular infections and the associated factors in Arba Minch, southern Ethiopia. An institution-based cross-sectional study was conducted among 259 suspected individuals with external ocular infections from 01 January to 10 June 2020 in Arba Minch General Hospital. The demographic data were obtained using a structured questionnaire, while corneal scrapings and conjunctival swabs were collected for culture. Samples were inoculated onto MacConkey, blood, mannitol salt and Sabouraud dextrose agar plates. Bacteria were characterised using conventional microbiological techniques. Fungal isolates were identified by culture and morphology by means of microscopy. Antibiotic susceptibility tests for bacteria were performed via the Kirby-Bauer disk diffusion technique. A logistic regression analysis determined the association between dependent and independent variables; P values ≤ 0.05 were considered statistically significant. The most common clinical manifestations in culture-proven cases were conjunctivitis (38.6%, n = 100) and blepharoconjunctivitis (25.9%, n = 67). The overall prevalence of external ocular bacterial and fungal infections was 73.2 (n = 115) and 26.8% (n = 42), respectively. Isolates of Staphylococcus aureus (24.8%, n = 39) and Pseudomonas aeruginosa (13.4%, n = 21) were the predominant Gram-positive and Gram-negative bacteria, respectively. The prevalence of multidrug-resistant bacteria was 71.3% (n = 82). The World Health Organisation-prioritised bacteria such as methicillin-resistant S. aureus (61.5%, n = 24), extended-spectrum beta-lactamase (22.6%, n = 12), and carbapenemase-producing Enterobacteriaceae (15.1%, n = 8) were also detected. The prominent fungi recovered from patients with keratitis and conjunctivitis were Aspergillus spp. and Candida albicans, respectively (9.5%, n = 15 each). Age (26–49 years) and family income were statistically associated with ocular infections (P ≤ 0.05). The results provide insights into the characteristics of major ocular bacterial and fungal pathogens circulating in the ophthalmic patients of Arba Minch. Conjunctivitis is the main ocular manifestation observed, with a predominance of S. aureus. More than two-thirds of the ocular bacteria were MDR, and the highest prevalence corresponds to S. aureus. The aggravation of multi-drug resistance, including the WHO-prioritised ones, warrants periodic evaluations.

Bacterial profile and antimicrobial susceptibility patterns of isolates from inanimate objects used by healthcare professionals at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia.

Healthcare-associated infections occur in patients under medical care, which is a major public health issue in hospitals worldwide. The prevalence is two to three folds higher in developing countries compared to developed countries. Inanimate objects used by healthcare professionals such as gowns, mobile phones, and stethoscopes are highly prone to bacterial contamination from the healthcare setting. In Ethiopia, there is a paucity of published data on the bacterial profile and susceptibility patterns of an isolates. To determine the bacterial profile and antimicrobial susceptibility patterns from inanimate objects used by healthcare professionals and associated factors at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia. A cross-sectional study was conducted at Debre Markos Comprehensive Specialized Hospital from inanimate objects from April 10, 2023 to June 30, 2023 using simple random sampling technique with lottery method. Socio-demographic data was collected using a structured questionnaire. A swab sample from healthcare professionals' gowns, mobile phones, and stethoscopes were collected and inoculated onto blood agar, chocolate and MacConkey agar. Isolates were identified and characterized by colony morphology, Gram staining and biochemical tests. Antimicrobial susceptibility testing was performed in all isolates by the disk diffusion technique on Muller Hinton agar according to CLSI, 2022 guidelines. Data was entered into EPI-Data and analyzed using SPSS version 25. Logistic regression model was used. Variables with p-value ≤ 0.25 in bivariable logistic regression was fitted to multivariate logistic regression analysis. A p-value of ≤ 0.05 with 95%CI was considered statistically significant. A total of 376 healthcare professionals' inanimate objects were included from 191 study participants. Overall, 60.1% (226/376) (95%CI: 55.1-65) inanimate objects were contaminated. The proportion of bacterial contamination was (65.1%; 82/126), (60.3%; 76/126) and (54.8%; 68/124) for mobile phones, gowns and stethoscopes, respectively. Staphylococcus aureus was the most frequent isolate accounting (22.1%; 83/376) followed by Staphylococcus epidermidis (17.0%; 64/376), Escherichia coli (8.8%; 33/376) and Pseudomonas aeruginosa (4.9%; 18/376). Working in gynecology/ obstetrics wards (AOR: 8.69; 95%CI: 1.09-69.41, P = 0.041), did not disinfect mobile phones (AOR: 2.69; 95%CI: 1.15-6.25; P = 0.021) and stethoscopes regularly (AOR: 3.06, 95%CI: 1.23-7.59; P = 0.016), carry mobile phones with patient care materials (AOR: 2.72; 95%CI: 1.18-6.29, P = 0.019) and not taken infection prevention training (AOR:3.91; 95%CI:1.71-8.93; P = 0.001) were significantly associated with bacterial contamination.Most Gram-negative bacteria were resistant to ampicillin, trimethoprim-sulfamethoxazole and amoxacilline-clavunic acid, while Gram-positive isolates showed high level of resistant to penicillin. On the other hand, meropenem, for Gram-negative and clindamycin for Gram-positive bacteria showed lower level of resistance. Multidrug resistance among Gram-positive and Gram-negative bacteria were (62.6%; 92/147) and (75.3%; 64/85), respectively with over all MDR (67.2%, 156/232). Inanimate objects commonly used by healthcare professionals are important sources of bacterial contamination. S. aureus, S. epidermidis and E. coli were the predominant isolates. Most Gram-negative bacteria were resistant to ampicillin while Gram-positive isolates showed high level of resistant to penicillin. All healthcare professionals should regularly disinfect their inanimate objects to prevent bacterial colonization and potential spread of infection.

Evaluation of Standard Wire Loop Method in Determination of Significant Bacteriuria among Pregnant Women in Ekpoma

Standard wire loop method is a time-tested method for UTI diagnosis. The term "bacteriuria" means the presence of bacteria in urine. It may result from contamination during or after collection of urine or it may indicate the presence of bacteria in the bladder urine. There are several cultural quantitative techniques for determining bacteriuria but standard wire loop method is the most popular method though relatively simple and cheap. This study was carried out to evaluate the standard wire loop method for determination of significant bacteriuria among pregnant women in Ekpoma. A total of one hundred (100) early morning mid-stream urine samples from pregnant women attending antenatal clinics in Ekpoma and environs were collected aseptically using sterile, wide-mouthed, leak-proof universal bottles. Microscopic examination was carried out to detect the presence of pus cells, epithelial cells, red blood cells, yeast cells, crystals, parasites, bacteria and casts. Undiluted urine, 1:10and 1:1000 diluted urine samples were aseptically inoculated into blood agar and MacConkey agar using the Standard Loop method and compared with Miles and Mirsa method, it was incubated at 370C aerobically for 24 hours. After incubation colonies were counted and isolates identified by standard biochemical methods. Colony count of ≥105 CFU per ml were considered as significant growth. In vitro antibiotics susceptibility of bacterial isolates was determined using disc diffusion technique. The data generated was analyzed statistically using the chi-squared statistics to ascertain the significance of the results. Out of 100 urine samples collected 39(39%) samples yielded significant bacterial growth, while 61(61%) of the samples had no significant bacterial growth or no growth with higher prevalence in age group &lt;25 years which is a sexually active group than in other age group ≤35 years which had incidence rate of 12 (25%). Standard loop method gave false positive rates of 4/35 (11.4%) and false negative rates of 4/36 (11.1%). The standard loop was found to have a sensitivity of 100%, specificity of 88.9% and identical results in 76.3% of the samples. To reduce bacteriuria and consequently prevent UTIs, it is necessary to take the precautions by doing regular routine check-ups and appropriate treatment. For large scale urine surveys the method chosen should be reasonably accurate, fast and simple to use. The materials required should be minimal, stable and easily transported. It is recommended that the method of choice for most laboratories is the standard loop method.