Agar Disc Diffusion Method Research Articles

Interactions of Chitosan-coated Green Synthesized Silver Nanoparticles using Mentha spicata and Standard Antibiotics against Bacterial Pathogens.

Infectious diseases are caused by various multidrug-resistant pathogenic bacteria and in recent scenarios, nanoparticles have been used as innovative antimicrobial agents. This current research aimed to evaluate the bactericidal effect of chitosan-coated green synthesized silver nanoparticles using aqueous extract of Mentha spicata (MSaqu) against bacterial pathogens, i.e., Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, and Streptococcus pyogenes. Synthesis and characterization of silver nanoparticles (MSAgNPs) were carried out via atomic absorption spectrometer and Fourier-transform infrared spectroscopy. Agar well and agar disc diffusion methods were used to assess the antibacterial and synergistic effect of chitosanmediated biogenic silver nanoparticles and standard antibiotics. Three types of interactions, i.e., antagonistic (↓), synergistic (↑), and additive (¥) were observed. Synergistic effect was recorded against Pseudomonas aeruginosa (8.5±0.25 mm↑), Serratia marcescens (19.0±1.0 mm↑), and Klebsiela pneumonia (8.5±0.25 mm↑), an additive effect was exhibited by Escherichia coli (9.0±0.0 mm¥), Streptococcus pyogenes (10.0±0.0 mm¥), and Staphylococcus aureus (7.5±0.25 mm↓) and they showed antagonistic effects when chitosan-coated silver nanoparticles (CLMSAgNPs) were applied compared to chitosan, MSaqu, and MSAgNPs. Interesting antibacterial results were recorded when chitosan-coated Mentha spicata extract and silver nanoparticles were applied along with antibiotics. The synergistic effects of chitosan-coated silver nanoparticles (CLMSAgNPs) + K were recorded against E. coli (14.5±0.25 mm). The synergistic effects of chitosan-coated silver nanoparticles (CLMSAgNPs) + AML were recorded against E. coli (5.5±0.0 mm), S. pyogenes (10.0±0.0 mm), K. pneumonia (5.5±0.0 mm), and S. aureus (4.0±0.0 mm). The synergistic effects of chitosan-coated silver nanoparticles (CLMSAgNPs) + NOR were recorded against E. coli (16.0±0.0 mm), P. aeruginosa (19.0±0.0 mm), S. marcescens (19.5±0.25 mm), S. pyogenes (11.5.0±0.25 mm), K. pneumonia (23.0±0.0 mm), and S. aureus (8.5±0.25 mm). Current findings concluded that chitosan-coated biogenic silver nanoparticles have potential bactericidal effects against infectious pathogens and could be used as forthcoming antibacterial agents.

Diversity and antibiograms of bacteria isolated from cutaneous leishmaniasis wounds in the Nkwanta South District of Ghana.

Leishmaniasis is a vector-borne disease caused by an intracellular protozoan parasite. The presence of secondary bacterial infections in cutaneous leishmaniasis wounds exacerbate lesion development and could lead to delay in the healing process. This study sought to determine the resistance patterns of bacteria co-infecting cutaneous leishmaniasis wounds from selected communities in the Nkwanta district. Various bacteria were isolated and characterized from exudates obtained from wound swabs collected with sterile cotton tipped applicators. Confirmation of bacterial identity was done using the analytical profile index and the matrix-assisted laser desorption/ionization time of flight mass spectrometry. Antibiotic susceptibility tests were performed using agar disc diffusion method according to the Clinical and Laboratory Standards Institute breakpoint values. A total of eleven (11) secondary bacterial species (spp) were isolated from the 33 wound samples that tested positive for Leishmania kinetoplast DNA, among which Staphylococcus aureus was the most predominant (31%). The pathogenic bacteria that colonized the wounds included Bacillus subtilis (23.8%), Pantoea species (11.9%), Klebsiella pneumoniea (7.1%), Enterobacter cloacae (7.1%), Aeromonas species (4.8%), Serratia marcescens (4.8%), Serratia liquefacien (2.4%), Serratia plymutheca (2.4%), Providencia rettgeri (2.4%) and Cronobacter species (2.4%). Most of the isolates were resistant to beta-lactam antibiotics and the third-generation cephalosporin. Notably, 84.6% of the S. aureus isolates were methicillin and ciprofloxacin resistant whilst 92.3% were resistant to ampicillin. About sixty-nine percent (69.2%) showed intermediate susceptibility to Erythromycin. Additionally, S. plymutheca was resistant to all the test antibiotics. This study suggests colonization of cutaneous leishmaniasis wounds with varied bacterial species that are mostly resistant to beta-lactam group of antibiotics.

Isolation and Identification of Bioactive Actinomycete Isolates from Yemen Soils

A total of 50 actinomycete isolates were isolated from different locations in Yemen (Sana’a, Taiz, Ibb and Alhodida). Agar disc diffusion method that used for screening antibacterial and antifungal activities were more effective and give better results than agar well diffusion method. Antibacterial activity of isolates was more effective than antifungal activity. All five selected isolates for study were active against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Candida albicans and Microsporium canis. According to taxonomy of actinomycetes (Morphological, physiological, biochemical and chemotaxonomy characters), all selected isolates were identified as members belonging to genus Streptomyces (S. glaucescenes, S. luridus, S. antibioticus, S. exfoliatus and S. filipinensis).

Occurrence and antimicrobial resistance pattern of E. coli O157:H7 isolated from foods of Bovine origin in Dessie and Kombolcha towns, Ethiopia.

E. coli are frequently isolated food-borne pathogens from meat, milk, and their products. Moreover, there has been a significant rise in the antimicrobial resistance patterns of E. coli O157:H7 to commonly used antibiotics. A cross-sectional study was conducted from October 2019 to July 2021 to estimate prevalence and identify associated factors of E. coli and E. coli O157:H7 and to determine antibiotic resistance pattern of E. coli O157:H7 from foods of bovine origin in Dessie and Kombolcha towns. A total of 384 samples were collected. Systematic and simple random sampling techniques were employed for sampling carcasses and milking cows, respectively. E. coli and E. coli O157:H7 were detected according to recommended bacteriological protocols. E. coli O157:H7 strains were evaluated for in vitro antimicrobial susceptibility using agar disk diffusion method. Both descriptive and inferential statistical techniques were applied to analyze the data. Overall prevalence rates of E. coli and E. coli O157:H7 were 54.7% and 6.5%, respectively. Highest prevalence rates of E. coli (79.6%) and E. coli O157:H7 (16.7%) were obtained from carcass swabs and milk tank samples, respectively. Unlike E. coli O157:H7, a statistically significant difference in the E. coli prevalence (P<0.05) was observed among the different sample types. Multidrug resistance was observed among all isolates of E. coli O157:H7. All E. coli O157:H7 isolates (100.0%) were susceptible to Ampicillin, Sulfamethoxazole-trimethoprim, and Norfloxacin. On the contrary, all of the isolates (100%) were resistant to Penicillin G, Vancomycin, and Oxacillin. The current study indicated that different foods of bovine origin in the study area were unsafe for human consumption. Hence, good hygienic production methods should be employed to ensure the safety of foods of bovine origin.

Effect of Lactobacillus spp. cell-free supernatant against planktonic growth and biofilm formation of foodborne Escherichia coli isolates.

The aim of this work was to evaluate the anti-Escherichia coli effect of cell-free supernatant (CFS) of Lactobacillus spp. against planktonic and biofilm forms of foodborne isolates. Escherichiacoli strains (P12, P25, P35 and P36), previously isolated from fresh filets of fish, were subjected to antimicrobial susceptibility determination by the disc-diffusion agar method. Subsequently, the antagonistic effect between probiotic and pathogenic strains was determined by spot overlay assay. Finally, the CFS activity against pre-established (12h) biofilms was demonstrated through biomass quantification by crystal violet staining and scanning electron microscopy (SEM). All isolates presented some pattern of resistance, primarily to ampicillin and tetracycline. Probiotic strains presented high antagonistic effects against all E. coli strains, presenting inhibition zones (R) ranging from 15.60 to 20.67mm. Additionally, the residual biomass of pre-established (12h) biofilm was drastically reduced about 50% after CFS treatment (P<0.01). What can be noted by SEM images, which show less surface-attached cells of CFS-treated biofilms of E. coli (P12). Thus, cell-free preparations produced from Lactobacillus spp. may represent a tool in the battle against planktonic cells and biofilm forms of antibiotic-resistant E. coli.

Antibiotic resistance genes and molecular typing of Streptococcus agalactiae isolated from pregnant women

BackgroundThe antibiotic resistance of genital tract colonizing Streptococcus agalactiae in pregnant women is increasing. We aimed to determine the antibiotic resistance genes of different clonal types of this bacterium in pregnant women.MethodsFour hundred twenty non-repeated vaginal and rectal specimens were collected from pregnant women and were transferred to the laboratory using Todd Hewitt Broth. The samples were cultured on a selective medium, and the grown bacteria were identified by standard microbiological and biochemical tests. Antimicrobial resistance pattern and inducible clindamycin resistance of the isolates were determined using the disk agar diffusion method. The genomic DNAs of S. agalactiae strains were extracted using an extraction kit, and the antibiotic resistance genes and RAPD types were detected using the PCR method.ResultsThe average age of the participants was 30.74 ± 5.25 years. There was a significant relationship between the weeks of pregnancy and the number of positive bacterial cultures (P-value < 0.05). Moreover, 31 pregnant women had a history of abortion, and 18 had a history of membrane rupture. Among 420 specimens, 106 S. agalactiae isolates were detected. The highest antibiotic resistance rate was found against tetracycline (94.33%), and all isolates were susceptible to linezolid. Moreover, 15, 15, 42, and 7 isolates showed an iMLSB, M-, cMLSB, and L-phenotype. The ermB was the most prevalent resistance gene in the present study, while 38 (35.84%), 8 (7.54%), 79 (74.52%), 37 (34.9%), and 20 (18.86%) isolates were contained the ermTR, mefA/E, tetM, tetO, and aphA3 gene, respectively.ConclusionsThe high-level antibiotic resistance and prevalence of resistance genes may be due to the arbitrarily use, livestock industry consumption, and the preventive use of antibiotics in pregnant women. Thus, the need to re-considering this problem seems to be necessary.

Antibiotic Resistance of Microbiotas of Fishery Enterprises Hydro Ecosystems

The aquatic environment is an integral part of biocenosis that directly affects its condition and safety in terms of epidemiology and epizootology. The study of the aquatic environment for the presence of pathogens and the quantitative characteristics of sanitary-indicative microorganisms is extremely important. The obtained data allow us to assess and predict the risks of infections, and to develop a plan of measures to prevent the spread of certain pathogens. The aim of the work. To analyze the microbial state of the aquatic environment in different hydro ecosystems of fish farms in the Kharkiv region and to assess the presence of microbiological risks to public health. Methods. The research objects were 150 samples of water taken from different hydro ecosystems in the Kharkiv region. Water was taken from closed water supply systems (n=30) and from ponds (n=120), where commercial fish is bred for sale. The presence and number of sanitary-indicative microorganisms and pathogenic bacteria were determined by the bacteriological (cultural) method. Resistances to antibacterial drugs in selected sanitary-indicative microorganisms were determined using the Agar disk-diffusion method. Estimation of the reliability of the difference between the compared indicators was determined using Student’s t-test. Results. The dominant sanitary-indicative microorganisms in the aquatic environment of fish farming were bacteria of the genus Citrobacter spp., Aeromonas spp., and Pseudomonas spp. The total bacterial contamination of water bodies ranged from 1.9±0.50×104 to 2.1±1.20×105 CFU in 1 cm3 of water. No pathogenic to humans bacteria have been detected. Isolated sanitary-indicative microorganisms had significant resistance to antibacterial drugs. Resistance to penicillins, sulfonamides, and nitrofurans was the highest (p=0.0001). The percentage of penicillin resistance strains ranged from 81.5% to 87.0%, sulfonamide — from 74.1% to 94.4%, and nitrofuran — from 55.5% to 66.7%. Fluoroquinolone and cephalosporin resistance varied depending on the type of antibacterial substance, but it did not exceed 29.6%. Conclusions. According to the research results for the aquatic environment of fish farms in the Kharkiv region, no pathogenic microorganisms were detected. However, it has been established that sanitary-indicating microorganisms (Citrobacter spp., Aeromonas spp., Pseudomonas spp.), which were dominant and had polyresistance to antibacterial drugs, may be risk factors for human health. Thus, the hydro ecosystems of fish farms have favorable conditions for the accumulation of bacterial strains resistant to antibiotics. Therefore, the use of antibacterial drugs should be scientifi cally justifi ed and strictly controlled.

Response surface methodology optimization and antimicrobial activity of berberine modified trimethoprim carboxymethyl cellulose

Abstract In order to solve the problem of bacterial resistance, increase the antibacterial performance and delay the aging of paper, the berberine modified trimethoprim carboxymethyl cellulose was prepared using trimethoprimethylate carboxymethyl cellulose as raw material and trimethoprimethylate lactate (TMP) as antibacterial modifier by Schiff Base reaction. At the same time, berberine (BBR) was used as graft monomer to prepare a multifunctional protective solution integrating strengthening, antibacterial and good biocompatibility. The optimal process conditions were determined by single factor experiment and response surface method. The structure and properties of the product were characterized by FT-IR, XRD, TG and SEM and the antibacterial properties were evaluated by AGAR disk diffusion method. The results showed that when the mass ratio of dialdehyde carboxymethyl cellulose and modified berberine was 7:15, reaction temperature was 40 °C, and pH was 6.0, the optimum synthetic conditions was obtained. And the minimum inhibitory concentration of the product against Staphylococcus aureus and Escherichia coli were 0.2 mg/mL, minimum diameter of antibacterial zone of 6.7 mm and 7.1 mm, respectively, with good antibacterial effect. This paper lays a foundation for further research on the safe and effective antiquities antibacterial agent, and provides a reference for its further development in paper protection.

Role of MexAB-OprM efflux pump in the emergence of multidrug-resistant clinical isolates of Pseudomonas aeruginosa in Mazandaran province of Iran.

Multidrug-resistant clinical isolates can cause many therapeutic problems. The MexAB-OprM efflux pump plays a significant role in expelling toxins and drugs from the bacterial cells resulting in multidrug-resistant Pseudomonas aeruginosa isolates. This study aimed to investigate the effect of the MexAB-OprM efflux pump in the emergence of multidrug-resistant clinical isolates of P. aeruginosa. For the present study, 100 clinical isolates of P. aeruginosa were collected from different wards of teaching hospitals (2018-2019). After confirmation and detection of bacteria by standard methods, the antibiotic resistance pattern of the isolates was determined by the disk agar diffusion method. Also, the minimum inhibitory concentration (MIC) of ciprofloxacin was measured in the presence and absence of phenylalanine arginine beta-naphthylamide by the broth microdilution method. Then, the real-time PCR was used to investigate the expression level of the mexB gene compared to the standard PAO1 strain. Forty-one/100 isolates exhibited multidrug-resistant phenotype (MDR), while piperacillin-tazobactam and levofloxacin were the most and least effective antibiotics tested, respectively. Also, 54/100 isolates showed no increased expression of mexB gene compared to the standard PAO1 strain. However, among the 41 MDR isolates, 12 (29.26%) showed a more than three-fold increase in the expression level of the mexB gene. In this study, a significant relationship was observed between the resistance to tested antibiotics in MDR strains and the increased expression of the mexB gene. We found that increasing the expression of the mexB gene can cause the emergence of multidrug-resistant strains by increasing the minimum inhibitory concentration of the antibiotics. Then, we need to evaluate the resistance mechanisms separately in different area of a country to improve the antibiotic stewardship.

Synthesis of novel tetrazolic derivatives and evaluation of their antimicrobial activity

The microbial resistance to various anti-infective drugs remains a major worldwide health problem. Therefore, the search for novel and effective antimicrobial agents is of paramount importance to combat these pathogenic microorganisms. The present study includes the synthesis of novel Bis(arylidene-2-[(tetrazol-5-yl)]alkane derivatives and the evaluation of their antibacterial and antifungal activities against four bacterial strains (Listeria innocua, Escherichia Coli, Pseudomonas aeruginosa, Staphylococcus aureus) and four fungal strains (Candida albicans, Rhodotorula glutinis, Geotrichum candidum, Aspergillus niger). These tetrazoles derivatives were prepared with moderate yields and their structures were determined on the basis of spectroscopic analyses, including FT IR, NMR, and HR-ESI-MS. Subsequently, these compounds and their precursors were tested in vitro for their antibacterial and antifungal activities, using the agar-disc diffusion method. All synthesized compounds at concentration of 1 mg/ml exhibited some antimicrobial properties against the tested fungal and bacterial strains. Finally, the docking study on the Biotin protein ligase in Staphylococcus aureus, showed that all molecules interact with the active site.

PREPARATION AND ANTI-MICROBIAL STUDY OF KASASHWASAVIDHUNANO RASA IN-VITRO

Kasashwasavidhunano Rasa is a drug used in Respiratory disorders in the Indian System of Medicine. It is an herbomineral formulation made up of Parad, gandhak, yavakshara, ruchaka lavana, and maricha churna by triturating in Tulsi patra Swarasa and indicated in Shwasa, Kasa. This action of Kasashwasavidhunano Rasa may be due to its antimicrobial activity so the in vitro antimicrobial activity was assessed by the Agar Disc Diffusion method concerning streptococcus pneumonia and Morxella catarrhal. Objective: To prepare and evaluate the antimicrobial effect of Kasashwasavidhunano Rasa. Method: Kasashwasavidhunano Ras was prepared using the reference of Yogratnakar. Parada (Mercury) and Gandhak (sulfur) were purified and then triturated to form Kajjali. Then raw drugs of maricha were converted into powder form, and all the ingredients i.e. kajjali, maricha churna, yavakshar, ruchaka lavana were mixed and triturated with the help of Tulsi swaras. The final product was in churna from which it was dried and stored. The antimicrobial activity of Kasashwasavidhunano Ras against streptococcus pneumonia and morxella catarrhal bacteria was evaluated using the agar cup diffusion method. Result: Kasashwasavidhunano Ras shows a significant antibacterial spectrum against streptococcus pneumonia and morxella catarrhal. Conclusion: This study shows that Kasashwasavidhunano Ras has antimicrobial potency and it can be clinically used for infectious respiratory disorders.

Isolation Identification and Antimicrobial Susceptibility Pattern of Salmonella and S Aurous from Selected Dairy Farms in Beedle and Nekemte Districts Western Ethiopia

Background: Bacterial diseases transmitted through food pose a serious threat to human and animal health. Salmonella and S. aurous are among the major foodborne pathogens. It is becoming a worldwide problem to date. In this regard, there is a lack of information among farms in western Ethiopia. Therefore, the study was conducted to isolate, identify, and assess the antimicrobial susceptibility profile of Salmonella and S. Aureus from Selected Dairy Farms in the study area. Methodology: A cross-sectional study was done from December 2018 to June 2019 on small scale dairy farms from Bedele and Nekemte town, Western Ethiopia with the objective of isolating and identifying Salmonella and S. Aureus from lactating cows, milkers’ and milking equipment at farms and to determine the antimicrobial susceptibility of the isolates. A total of 383 samples consisting cow milk, feces, cow nasal swab, milkers’ hand swab, milkers nasal swab, bucket swab, and floor swab were collected from 20 dairy farms. The samples were examined for the presence of Salmonella and S. Aureus following standard techniques and procedures. Agar disc diffusion method was used for the antimicrobial susceptibility testing. Results: The overall occurrence of Salmonella and S. Aureus was 2.35%and 2.35% respectively. Out of the 9 Salmonella isolates, 5(4.95%), 3(2.97%), and 1(5%) were isolated from udder milk, rectal feces and floor swab respectively. S. Aureus isolate was highest in udder milk 3(2.97%), followed by cow nasal swab 2(1.98%), feces 1(0.99%), bucket swab 1(5%), floor swab 1(5%) and milker’s nasal swab 1(5%). All salmonella isolates were 100% sensitive to nalidixic acid, however 55.55%, 22.22 %, and 11.11, respectively, were resistant to cefoxitin, tetracycline, and gentamycin. The antibiotic susceptibility profiles of the S. Aureus showed that 55.55% and 11.11% were resistant to Penicillin G and Erythromycin, respectively and were 100% sensitive to cefoxitin, nitrofurantoin, and gentamicin. Conclusion: Even if the current study shows lower prevalence, lower antimicrobial resistance and higher susceptibility for most antimicrobials, stringent control measures, such as treatment of positive cases with effective medications and preventative measures including strict hygiene standards, such as cleaning of the floor, pens, and milking equipment, as well as adequate hand washing throughout the milking process, should be adopted.

Antimicrobial susceptibility of bovine clinical mastitis pathogens in Japan and development of a simplified agar disk diffusion method for clinical practice.

This study aimed to examine the antimicrobial susceptibility of bovine mastitis pathogens in Japan and develop criteria for testing antimicrobial susceptibility using the simplified agar disk diffusion (ADD) method that is currently being used in clinical practice. Milk samples from 1,349 dairy cows with clinical mastitis were collected and cultured. The minimum inhibitory concentrations (MICs) of the antimicrobials were determined for 504 strains of 28 bacteria. Of the gram-positive bacteria, most Staphylococcus spp. were susceptible to penicillin G (PCG), kanamycin (KM), oxytetracycline (OTC), cefazolin (CEZ), pirlimycin, enrofloxacin, and marbofloxacin. Streptococcus spp. and Trueperella pyogenes showed resistance to OTC and KM. Most gram-negative bacteria were resistant to OTC and CEZ and particularly susceptible to fluoroquinolones. To develop the criteria for a disk diffusion test of the simplified ADD method, the relationships between MICs and diameters of inhibition zones (DIZs) were analyzed and compared with the conventional method. The susceptibility breakpoints of several antimicrobials were lower for both gram-positive and gram-negative bacteria. Particularly for gram-positive bacteria, the application of the new criteria lowers the breakpoint for PCG, suggesting that the use of PCG instead of CEZ may increase. The results suggest that use of these criteria for the simplified ADD method may lead to appropriate antimicrobial choice and consequently the appropriate use of antimicrobials in clinical practice.

In-Vitro EVALUATION OF PHYTOCHEMICALS, HEAVY METALS AND ANTIMICROBIAL ACTIVITIES OF LEAF, STEM AND ROOTS EXTRACTS OF Caltha palustris var. alba

Plants are a rich source of secondary metabolites that have been found to have medicinal properties. The present study was conducted to evaluate the phytochemical screening, antimicrobial activities, and heavy metal analysis in different parts (leaves, stem and roots) of Caltha palustris var. alba. The phytochemical analysis for the plant was carried out in ethanol, acetone, ethyl acetate, n-hexane and deionized water extracts. The phytochemical screening confirmed the presence of several bioactive compounds like, alkaloids, flavonoids, tannin, phenols, and saponin. The antimicrobial activity was determined by the agar disc diffusion method using five different extracts. The antimicrobial study revealed that the C. palustris var. alba has the ability to fight against the selected microorganism. The phytochemical and biological screenings were correlated with the presence of heavy metals in selected plant C. palustris var. alba. The concentrations of heavy metals were determined by atomic absorption spectrophotometer and revealed the presence of the metals like cadmium, manganese, zinc, copper, lead, and chromium. The metal concentration was compared with the permissible limit set by World Health Organization (WHO) and the result was discussed. From these studies, it is clear that plant C. palustris var. alba can be used for medicinal purposes.

Phytochemical Screening, Antioxidant and Antimicrobial Activity of Andrographis paniculata

As a magician in India, Andrographis paniculata is called Crete or the King of Bitters because of its bitter taste. It is known for ethnic medicine to treat diseases, inflammation, cold, fever, snake bite, diarrhea, dysentery, jaundice, kidney disease and antioxidant. This study was done by preparing the solution in ethanol for the whole plant. Phytochemical analysis was performed due to the presence of important drugs as well as phenols, tannins, flavonoids, saponins, glycosides, steroids, terpenoids and alkaloids. It has been reported that these secondary metabolites have many biological and therapeutic properties, so it is expected that this species has many medicinal applications. It is rich in phenols, flavonoids and alkaloids and exhibits antioxidant and antimicrobial properties (including antibacterial and antifungal). This study was conducted using the agar disc diffusion method, in which the extract shows antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger and Candida albicans, and may be the ingredients used in the method. The source of the antibiotic depends on the concentration. In addition, by several free-flow studies, the antioxidant capacity of paniculata plants has been confirmed. Therefore, they are also effective antioxidants and have anti-cancer properties.

Relationship of OqxAB efflux pump to antibiotic resistance, mainly fluoroquinolones in Klebsiella pneumoniae, isolated from hospitalized patients.

This research was designed to study the prevalence of OqxAB efflux pump genes and also to investigate the relationship between efflux pump and resistance to antibiotics, especially to fluoroquinolones, evaluate the expression levels of OqxAB genes, and molecular typing of Klebsiella pneumoniae isolated from hospitalized patients in Hamadan hospitals, west of Iran. In a cross-sectional study, 100 clinical strains of K. pneumoniae were isolated from hospitalized patients in three major teaching hospitals from January to June 2021. The antibiotic susceptibility of isolates was evaluated by the disk-diffusion agar method. The frequency of genes encoding oqxA and oqxB of efflux pump genes was investigated by PCR, and the expression of the oqxA efflux pump gene was investigated by the Real-time PCR method. The genetic relationship of K. pneumoniae isolates was analyzed by the Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR technique. According to our results, the multi-drug resistance phenotype (MDR) in 65% and high prevalence resistance to ciprofloxacin in 89% of K. pneumoniae isolates was detected. The higher prevalence of oqxA (95%) and oqxB (98%) was also detected. There was a significant relationship between ciprofloxacin resistance and the oqxB gene as well as between ceftriaxone and chloramphenicol resistance and the oqxA gene. The expression of the oqxA gene was higher in ciprofloxacin-resistant isolates. The results of this study suggest a potential reservoir for the spread of OqxAB genes among hospital-acquired bacteria. Infection control strategies should be used prudently to reduce the spread of resistant strains of K. pneumoniae in hospitals.

Antibacterial, Antioxidant Potency, and Chemical Composition of Essential Oils from Dried Powdered Leaves and Flowers of Hypericum revolutum subsp. keniense (Schweinf.).

Hypericum revolutum subsp. keniense is a plant mainly used to treat diarrhoea, rheumatism, nervous disorders, and wounds in African traditional medicine. The objective of the current work was to establish antibacterial, antioxidant potency, and chemical composition of essential oil from the leaves and flowers of Hypericum revolutum subsp. keniense. The oils were isolated by steam distillation. Antibacterial activity against methicillin-resistant Staphylococcus aureus, Staphylococcus aureus (ATCC 12393), Escherichia coli (ATCC 25922), Acinetobacter baumannii (ATTC 19606), Salmonella enteritidis (NCTC12023), Salmonella typhimurium (ATCC 14028), Pseudomonas aeruginosa (ATCC 15442), and Haemophilus influenzae (ATCC 49766) was carried out by agar disk diffusion and microtiter broth dilution methods. Antioxidant activities of the essential oils were examined by different methods, DPPH, FRAP, and H2O2 assays. Chemical characterization was performed using gas chromatography interfaced with mass spectrometry, Fourier-transform infra-red (FTIR) spectroscopy, and quantification of phenolics and flavonoids by Folin-Ciocalteu reagent and aluminium nitrate, respectively. The oils showed potential antibacterial activity with mean zone of inhibition ranging from 20.67 ± 0.33 to 32.00 ± 1.00 mm at 100% oil concentration against the tested bacteria. Furthermore, the minimum inhibitory concentrations (MICs) in all the tested microorganisms were in the range from 250 to 15.6250 μg/ml. The essential oils derived from the leaves revealed varied antioxidant activity levels with the different methods of assay. The IC50 of values obtained from the three methods, DPPH, FRAP, and H2O2 were ˃1000 μg/ml, 0.31 μg/ml, and 12.33 μg/ml, respectively. Caryophyllene (22.1%) and 2, 3, 4-trimethylhexane were the major chemical components of the essential oils derived from the leaves and flowers, respectively. FTIR spectroscopy of the essential oils from the leaves and flowers showed similarity at peaks for hydroxyl, unsaturated olefinic, and amine functional groups. Further findings indicated that the total phenolic and flavonoid contents essential oils derived from leaves were 130.4 6 ± 10.5 mg GAE/g dry weight and 0.911 ± 0.04 mg CE/g dry weight, respectively. It was therefore concluded that essential oils from the leaves and flowers of H. revolutum subsp. keniense have compounds that have antibacterial and antioxidant potency.

ANTIFUNGAL AND ANTIOXIDANT ACTIVITIES OF COBALT AND NICKEL METAL COMPLEXES OF P-AMINO BENZAMIDE

Cobalt and nickel bio-active metal chelates were synthesized using p-aminobenzamide and thiocyanate ion in an equimolar ratio, and they were assessed for conductivity, UV-Visible, IR, and far-IR spectra as well as metal ion estimation identification. Based on their spectral and magnetic characteristics, the complexes were given octahedral geometry. The complexes are paramagnetic, monomeric, and non-electrolyte. With the help of the Agar Disc diffusion method using fluconazole as the reference drug, the antifungal activity of metal chelates through an in-vitro mechanism was compared with p-aminobenzamide against C. albicans. Metal(II) chelates' in-vitro DPPH free radical scavenging ability was tested and contrasted with that of standard ascorbic acid. The complexes appear to have moderate activity, according to the results of the computation of the IC50 values at four distinct concentrations.

Molecular and Biochemical Characterization of Pseudomonas aeruginosa Isolated from a Turkey Flock

Pseudomonas aeruginosa is a Gram-negative, aerobic, mostly motile, non-spore-forming, catalase-positive bacterium responsible for nosocomial infections, food and waterborne diseases in the human population, and infection of different organs in avian species. Because of the emergence of multidrug-resistant isolates in recent years, the occurrence of infection in pet avian species or poultry can lead to severe infection in the human population. This study reports an infection in turkey poults related to Pseudomonas aeruginosa. Overall, eight 4-day-old dead turkey chicks were presented to SANA Avian Hospital to diagnose the cause of death. For this purpose after necropsy, liver and bone marrow were sampled and cultured on blood agar. Then other complementary biochemical tests were performed to achieve a primary diagnosis. After the primary diagnosis of Pseudomonas aeruginosa infection, at the next step, PCR was used for definitive diagnosis and evaluation of virulence factors. Finally, the agar disk diffusion method determined antimicrobial resistance to some common medications, and results were interpreted by Clinical and Laboratory Standards Institute guidelines.

Phytochemical and Antimicrobial Studies of Salvadora persica, Prosopis cineraria and Tamarix aphyla Plants from Cholistan, Pakistan

Viral and bacterial infections are causing havoc to human health, wildlife, poultry and livestock since long. Current study was designed to carry out investigation of the antiviral and antibacterial potential of leaves of Salvadora persica, Prosopis cineraria and Tamarix aphyla from Cholistan by using HA/IHA titers and Agar disc diffusion methods. Extracts of these plants were tested against 4 different viruses i.e. Newcastle Disease Virus (NDV), Infectious Bursal Disease Virus (IBDV), Infectious Bronchitis Virus (IBV) and Avian Influenza Virus (AIV-H9N2) and 5 different bacteria i.e. Proteus vulgaris, Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The drug ampicillin was used as a positive control. The results indicate that the n-hexane and ethyl acetate extracts were more effective against viruses and bacteria as compared to ethanol, methanol, n-butanol and aqueous extracts. In comparison of plants, the extracts of S. persica were found to have highest antiviral potential while on the other hand the extracts of T. aphyla showed the best activity against bacteria. Overall these plants were most effective against IBDV and least effective against NDV and in comparison of bacterial pathogens, these plants were found to be highly effective against P. vulgaris and least effective against P. aeruginosa.