Antibiotic Sensitivity Assay Research Articles

Microbiological assessment of bioaerosols in the residential areas of Dhaka City, Bangladesh

This study looked at particulate matter (PM10) in terms of its microbiological features and how bacterial populations are related to PM10. It also tested the antibiotic resistance of different types of microbes that live in PM10. We conducted the study in six different locations (Badda, Chittagong Road, Basabo, Jurain, Mirpur, and Gulshan) of Dhaka city, taking into account residential and commercially important areas, traffic congestion, and infrastructure development. The microbiological study revealed that Bacillus spp. and Staphylococcus spp. were primarily present in PM10. The study also revealed that the total bacterial count (46585±1226.8 CFU/m3) of the Badda zone is higher than in another area. Similar findings were also observed in the case of Bacillus spp. (15625±5729 CFU/m3), Staphylococcus spp. (18518±5730 CFU/m3), and total fungal count (726852± 98209 CFU/m3). Moreover, a positive correlation was observed among Bacillus spp. and Staphylococcus spp. vs. mean PM10 concentration, which implies that airborne microbes in Dhaka city are likely to propagate with the increase of dust concentration. The antibiotic sensitivity assay of Bacillus spp. and Staphylococcus spp. revealed that all the Bacillus spp. (n=16) and Staphylococcus spp. (n=3) were resistant to Ceftazidime (30 µg), Oxacillin (1 µg) and Cefixime (5 µg). So, the research findings highlighted the increased levels of Bacillus spp. and Staphylococcus spp. than the international standard in PM10 of Dhaka city, suggesting potential health risks and indicating antibiotic resistance among these bacterial strains.

Detection of Antibiotic Resistance Genes in Escherichia coli Isolated from Chicken Eggs

Total 150 chicken eggs were randomly collected from farms, households, and markets of Rajshahi and Naogaon districts. Isolation and identification of E. coli was done by using cultural and staining characteristics, and biochemical properties. Antibiotic sensitivity assay was also performed for the isolated E. coli by using disc diffusion method. Characterization and detection of antibiotic resistance genes in E. coli isolates were done through PCR analysis. Prevalence of E. coli was 30.00% in chicken eggs in Rajshahi and Naogaon districts. Results of antibiotic sensitivity patterns of the isolated E. coli showed 57.78%, 33.33%, 31.11%, 28.89%, 26.67%, 17.78%, 15.56%, 13.33%, 13.33%, and 11.11% resistance to ciprofloxacin, doxycycline, oxytetracycline, ceftriaxone, amoxycillin, erythromycin, levofloxacin, enrofloxacin, gentamycin, and neomycin, respectively. The isolates also showed 94.44%, 82.22%, 80.00%, 77.78%, 66.67%, 60.00%, 55.56%, 48.89%, 46.67%, and 33.33% sensitive to neomycin, enrofloxacin, erythromycin, levofloxacin, gentamycin, ceftriaxone, oxytetracycline, doxycycline, amoxicillin, and ciprofloxacin, respectively. All 45 phenotypic identified isolates were confirmed as E. coli by PCR analysis. Genotypic identified isolates of E. coli were further characterized by PCR to detect antibiotic resistance genes. Out of 45 E. coli isolates 37 (82.22%) showed tetracycline resistance (tetA) gene, 32 (71.11%) showed tetracycline resistance (tetB) gene, and interestingly all 45 (100%) isolates showed quinolone group resistance (gyrA) gene by PCR analysis. J. of Sci. and Tech. Res. 5(1): 135-142, 2023

Isolation and Molecular Characterization of Therapeutic Probiotic Lactobacillus from Different Sources in Ernakulam-Kerala

This study aims to present knowledge on therapeutic potential bacteriocin producing bacterial strains. Samples (n=35) from diverse Ernakulam sources yielded 26 lactic acid bacteria (LAB) isolates on De Man Rogosa Sharpe (MRS) medium. Among the isolates potent antimicrobial activity observed against known pathogens in one of the isolates from goat milk sample number 3, labelled as GO3. Microscopic and biochemical test revealed the isolate is Gram-positive rod, non-sporulating and resilience to pH and bile salts, with adaptability to gastric enzymes and surfactants. Genetic and physiological traits of the positive strains were confirmd by 16S rRNA technique. Blast analysis revealed that sequence of the strain GO3 from goat milk identified as Lactobacillus casei, exhibited antibiotic sensitivity, auto-aggregation, co-aggregation, and antibiofilm assays highlighted inhibitory properties as a promising therapeutic potential probiotic bacterium. LAB isolates can be further investigated at the genetic level to enhance their probiotic characteristics such as resistance and cellular adhesion. Additionally, the identification of gene responsible for expressing bacteriocins can be conducted on these isolates.

Identification and biological control of bacterial leaf spot disease of cucurbits

Objective: The present study was conducted for isolation and detection of the phyto-pathogen responsible for bacterial leaf spot disease of cucurbits as well as evaluation of its biological control techniques. Methods: The pathogen of the disease was isolated from infected leaf of bitter gourd and cultured on Luria-Bertani (LB) growth medium. The morphological tests and biochemical tests revealed the isolated bacteria as gram negative. Furthermore, advanced molecular technique was applied to facilitate proper detection of the isolated bacteria. The PCR of the bacterial genomic DNA using specific primers generated clear band of approximately 1450 bp in gel electrophoresis. Results: In gram staining test, the bacterial strain was found to be rod shaped and pinkish in color and Gram-negative. All the biochemical test showed positive without mannitol salt agar. The nucleotide sequencing of 16S rDNA gene of the bacterial isolate showed 86.02% similarities with the original sequence of Xanthomonas cucurbitae. In antibiotic sensitivity assay, the antibiotic cefixime showed highest 28.0±0.7 mm diameter of inhibition zone against the tested bacteria. The highest antibacterial activity was 8.0±0.5 mm zone of inhibition by of Allium sativum. Conclusion: The present findings may be benevolent for the detection, characterization and development of biological control techniques to prevent the leaf spot disease of cucurbits crops in Bangladesh. It may help to find out the specific signaling pathway techniques for plant microbes relationship for disease formation in future.

Antimicrobial profiling of mastitis causing bacteria in buffalo milk

Mastitis is causing huge economic losses to the dairy industry in India. The losses were mainly due to decreased milk production and treatment cost. This study was aimed to detect occurrence of mastitis in buffaloes. A total of 5,665 milk samples from buffaloes were processed for detection of mastitis by white side test (n=4,884) and culture examination (n=781). Overall, 2,808 (57.49%) milk samples were positive by white side test and 96.79% (n=756) samples were found positive by culture examination. Gram-positive and gram-negative bacteria were detected in 54.16% (n=423) and 31.11% (n=243) of the milk samples, respectively. Mixed infection of both was found in 10.62% (n=83) samples. While, Candida spp. was detected in 0.89% (n=7) samples only. Antibiotic sensitivity assay revealed that chloramphenicol was the most sensitive antibiotic against 71.61% samples in both gram-positive and negative bacterial isolates followed by enroloxacin, amikacin, levofloxacin, moxifloxacin and gentamicin in 71.09%, 61.77%, 58.85%, 58.59% and 55.99% samples, respectively. Kanamycin was most resistant against all isolates followed by neomycin (76.36%), norfloxacin (60.99%), amoxicillin+cloxacillin (52.78%), and ceftizoxime (51.85%).

Detection of genes conferring resistance on multi antibiotic resistance bacteria isolated from ready to eat foods sold in the Nigerian defence academy, Kaduna, Nigeria

Food has always been the means by which disease-causing organisms are transmitted to man. This study sought to isolate multi-antibiotic resistant bacteria from ready to eat food (RTE) sold within Nigerian Defence Academy. Eight (8) food samples were collected from five (5) vendors and spread plate technique was adopted for bacteria isolation from the food samples. Twenty-five (25) bacteria isolates were obtained from the food samples and subjected to antibiotic sensitivity assay using Kirby Bauer disc diffusion method. Eight (8) of the isolates exhibited various degrees of resistance to the tested antibiotics. All the isolated bacteria in this study were susceptible to the effect of Quinolones antibiotics and were resistant to cefuroxime, cefotaxime and Ampiclox. Six (6) of the isolates that showed multi-antibiotic resistance were characterized by 16SrRNA gene sequencing as Bacillus cereus strains (0083 and HYM76), Staphylococcus aureus strain MRSA252, Lactobacillus murinus strain AMB_10 and Listeria Spp. Polymerase chain reaction (PCR) and agarose gel electrophoresis detection of four (4) antibiotics resistance genes – Aminoglycoside adenylyltransferase (AADA1), Acridine (ACRA), Chloramphenicol Resistance (CMLA) and Erythromycin (ERM(C)) – produced the following results: AADA1 genes were amplified in Staphylococcus aureus and Bacillus cereus; ACRA gene was detected in all the selected isolates; CMLA gene was detected in Staphylococcus aureus, Lactobacillus murinus and Bacillus cereus while ERM(C) gene was present in Staphylococcus aureus.

Study of Endophytes as Biocontrol Agents Vis-a-Vis their Compatibility to Fungicides in Grapes

The present study was conducted at ICAR-National Research Centre for Grapes in Pune, Maharashtra, India during 2021–2022 to study endophytic bacteria as biocontrol agents vis-a-via their compatibility to fungicides in grapes. Eighteen endophytic bacteria were isolated from nine varieties of grapevine (Vitis vinifera L.) viz. Manjari Naveen (MN), Nanasaheb Purple (NP), Thompson Seedless (TS), Crimson Seedless (CS), Manik Chaman (MC), Maruti Seedless (MS), Fantasy Seedless (FS) and 2A Clone (2A). The distinct colonies were selected, sub-cultured, purified and subjected to analysis of macroscopic and microscopic features followed by screening of bacterial isolates for plant growth-promoting (PGP) traits, extracellular hydrolytic enzyme production, and abiotic stress tolerance assay. Eighteen diverse endophytic bacteria were found to be Gram positive to Gram negative and with white, whitish yellow and whitish red colonies. Different biochemical tests which were needful for the identification of the bacteria were performed. Antibiotic sensitivity and antifungal assays were conducted with five antibiotics and pathogenic fungi Colletotrichum gloeosporioides respectively. Results of dual culture plate assay for antimicrobial activity revealed that 10 isolates showed significant growth inhibition of the test pathogen and were selected for the compatibility studies. The results highlighted that most of the isolates were highly compatible with all the fungicides used for powdery mildew, downy mildew, anthracnose and bacterial leaf spot. The work indicated the importance of the endophytic bacteria which can be used as promising biocontrol agents for grapevine disease management.

Ganoderma Lucidum - A Potential Medicinal Mushroom Against MDR Isolates from The Secondary Infections of Covid-19

The severe acute respiratory syndrome produced by COVID-19 is a highly infectious and pathogenic viral infection. Many COVID-19 patients have secondary bacterial infections, which enhance disease and increase death, particularly when requiring invasive mechanical ventilation. One of the most important medicinal mushrooms, Ganoderma lucidum, has been used for food, feed, and medication since the dawn of humanity. The present investigation aims to discover the potential of the medicinal mushroom Ganoderma lucidum inhibited multidrug-resistant isolates from secondary infection of Covid-19 patients. Isolation and identification of urine samples from secondary infection of post-Covid-19 patients and evaluate the antibiotic sensitivity assay, as identification of bioactive compounds, anti-inflammatory and antioxidant activity from Ganoderma lucidum. Totally 6 clinical urine samples were collected from the age group 45 to 60; 3 were male, and 3 were female. In total, nine bacteria and 10 fungi were isolated and identified. As antibiotic sensitivity assays of ceftriaxone, fluoroquinolones, azithromycin and amphotericin, nystatin and fluconazole were performed by the disc diffusion method against bacteria and fungi, the zone of inhibition was maximal in Klebsiella pneumoniae and Fusarium oxysporum. The aqueous and ethanolic extracts of Ganoderma lucidum were analyzed for the bioactive compounds, viz., steroids, flavonoids, alkaloids and phenolic compounds. The effect of the anti-inflammatory activity of the aqueous extract was excellent. The activity of the DPPH assay was maximum in aqueous and ethanolic extracts of all concentrations (100 to 500 ml). Antibiotic resistance could probably rise due to the frequent prescription of broad-spectrum empiric antimicrobials to COVID-19 patients. Hence, Ganoderma lucidum can be exploited to prevent secondary infection in COVID-19 patients.

Quantitative Proteomics Reveal the Inherent Antibiotic Resistance Mechanism against Norfloxacin Resistance in Aeromonas hydrophila.

Recently, the prevalence of Aeromonas hydrophila antibiotic-resistant strains has been reported in aquaculture, but its intrinsic antibiotic resistance mechanisms are largely unknown. In the present study, a label-free proteomics technology was used to compare the differential protein abundances in response to norfloxacin (NOR) stress in A. hydrophila. The results showed that there were 186 proteins decreasing and 220 proteins increasing abundances in response to NOR stress. Bioinformatics analysis showed that the differentially expressed proteins were enriched in several biological processes, such as sulfur metabolism and homologous recombination. Furthermore, the antibiotic sensitivity assays showed that the deletion of AHA_0904, cirA, and cysI significantly decreased the resistance against NOR, whereas ΔAHA_1239, ΔcysA, ΔcysD, and ΔcysN significantly increased the resistance against NOR. Our results provide insights into NOR resistance mechanisms and indicate that AHA_0904, cirA, AHA_1239, and sulfur metabolism may play important roles in NOR resistance in A. hydrophila.

Antibiotic sensitivity pattern of uropathogens among diabetic and non-diabetic pregnant women in Dhaka, Bangladesh

Objective: To determine the urinary tract infections (UTIs)-causing bacterial profile and antibiotic susceptibility pattern for the proper and complete treatment of UTIs in pregnant women with diabetes mellitus (DM). Methods: We collected 300 urine samples from diabetic and nondiabetic pregnant women at various gestational ages. After isolating and identifying uropathogens, we conducted an antibiotic sensitivity assay against fourteen commonly used antibiotics: amikacin, amoxicillin, ampicillin, azithromycin, cefixime, ceftazidime, ceftriaxone, cefuroxime, ciprofloxacin, co-trimoxazole, gentamicin, levofloxacin, netilmicin, nitrofurantoin. Results: Among the participants, 70% had DM but only 37.3% had positive uropathogen growth. Five gram-negative bacteria (Escherichia coli, Klebsiella spp., Enterobacter spp., Citrobacter spp., and Pseudomonas spp.) and 3 gram-positive bacteria (Streptococcus spp., Staphylococcus spp. and Enterococcus spp.) were indentified. Escherichia coli was the most prevalent bacteria (57.1%), followed by Klebsiella spp. (19.6%). In the antibiotic susceptibility assay, we found 96.5% of the isolated organisms were highly susceptible to levofloxacin, 94.2% to netilmicin, 88.2% to nitrofurantoin, 85.1% to amikacin, 79.8% to gentamicin, respectively. On the other hand, 64.8%, 63.6%, 61.8% of the isolates demonstrated high-level resistance to ampicillin, ceftazidime and amoxicillin whereas 38.0%, 37.1%, 33.6%, 30.9% and 30.0% of the organisms were resistant to co-trimoxazole, azithromycin, ciprofloxacin, cefuroxime, cefixime, respectivey. Conclusions: Our results suggest that amikacin, levofloxacin, netilmicin, nitrofurantoin, and gentamycin can be used as first-line treatments for UTIs, whether the patient has DM or not. Contrarily, amoxicillin, ampicillin, ceftazidime, azithromycin, and co-trimoxazole should be avoided in treating UTIs.

Phenotypic Characterization of Certain Flavobacteria Species Infected Cultured Freshwater Fish

One of the most important and distributed bacterial disease in freshwater fish in Egypt is flavobacteriosis disease that caused by the gram-negative bacillus Flavobacterium which infects fish under stressful conditions and causing high mortality. In this study we have attempted to identify the possible infection of three flavobacteria app. (F. columnare, F. covae, and F. davissi) out of 200 cultured African catfish Clarias gariepinus and Nile tilapia tilapia niloticus. The Goal of this study was to isolate and characterize Flavobacteria species phenotypically, biochemically and detect the haemolytic virulence activity, beside evaluation antibiotics resistance activity of this bacterium. Despite, all flavobacteria species cause heamolysis to sheep blood agar that indicate to presence of heamolysine virulence gene but the F.columnare TIL2015 strain show no heamolysis on sheep blood agar. According to antibiotic sensitivity assay Gentamycin 30 μg, was the most effective antibiotic against the all tested Flavobacteria species, however F.columnare strains were sensitive against Doxycycline 30 μg, streptomycin 10 μg, beside gentamycin 30 μg. All isolates were resistant to amoxicillin 30 μg and Cefalexine 30 μg.

Multidrug Resistance and Virulence Factors of Enterococci Isolated from Milk and Some Dairy Desserts

Background: Enterococci spp. bacteria especially Enterococcus faecalis and E. faecium have the ability to acquire antibiotic-resistance pattern and causing life-threatening hospital-acquired infections. So, the aim of this study was to count and isolate of E. faecalis and E. faecium from milk and dairy desserts consumed in Assiut city, Egypt.
 Methods: A total of 100 raw milk, ice cream, mehallabia, and milk rice samples were collected from dairies shop in Assiut city, Egypt and were bacteriologically examined for the presence and count of Enterococcus spp. Then, identification of enterococci isolates by conventional and Polymerase Chain Reaction (PCR) methods, performance of antibiotic sensitivity assay, and some virulence genes in the Multi Drug Resistant (MDR) isolates were identified.
 Results: The prevalence of counted Enterococcus spp. in raw milk, ice cream, mehallabia, and milk rice samples were 76, 44, 20, and 32%, respectively. The prevalence of E. faecalis in raw milk, ice cream, mehallabia, and milk rice samples were 64, 0, 0, and 8%, while for E. faecium were 12, 44, 20, and 24%, respectively. E. faecalis isolates were resistant to vancomycin, ciprofloxacin, gentamicin, erythromycin, and tetracycline with the rate of 72.2, 88.9, 88.9, 94.4, and 77.8%, respectively, while for the resistance rates of E. faecium were 16, 40, 16, 84, and 20%, respectively. E. faecalis and E. faecium were MDR in rate of 88.9 and 32%, respectively.
 Conclusion: This study revealed that milk, ice cream, mehallabia, and milk rice could be a source of enterococci to consumers in Assiut, Egypt. Moreover, E. faecalis had higher MDR and Resistant Index (RI) than E. faecium.

Artificial sweeteners inhibit multidrug-resistant pathogen growth and potentiate antibiotic activity.

Antimicrobial resistance is one of the most pressing concerns of our time. The human diet is rich with compounds that alter bacterial gut communities and virulence-associated behaviours, suggesting food additives may be a niche for the discovery of novel anti-virulence compounds. Here, we identify three artificial sweeteners, saccharin, cyclamate and acesulfame-K (ace-K), that have a major growth inhibitory effect on priority pathogens. We further characterise the impact of ace-K on multidrug-resistant Acinetobacter baumannii, demonstrating that it can disable virulence behaviours such as biofilm formation, motility and the ability to acquire exogenous antibiotic-resistant genes. Further analysis revealed the mechanism of growth inhibition is through bulge-mediated cell lysis and that cells can be rescued by cation supplementation. Antibiotic sensitivity assays demonstrated that at sub-lethal concentrations, ace-K can resensitise A. baumannii to last resort antibiotics, including carbapenems. Using a novel exvivo porcine skin wound model, we show that ace-K antimicrobial activity is maintained in the wound microenvironment. Our findings demonstrate the influence of artificial sweeteners on pathogen behaviour and uncover their therapeutic potential.

Bacterial Profile, Antimicrobial Susceptibility Pattern, and Associated Factors among Dental Caries-Suspected Patients Attending the Ayder Comprehensive Specialized Hospital and Private Dental Clinic in Mekelle, Northern Ethiopia.

Background Dental caries is a major public oral infectious disease globally due to its high prevalence and significant social impact. Many studies have been conducted on dental caries in Ethiopia; however, they fail to convey the antimicrobial resistance in the oral environment. Objective This study was conducted to determine the antimicrobial susceptibility patterns and biofilm formation in the bacteria isolated from dental caries and its associated factors of dental caries in THE Ayder Comprehensive Specialized Hospital and private dental clinics located at Mekelle, Ethiopia. Methods A cross-sectional study was conducted from September 2019 to October 2020. Sociodemographic characteristic, behavioral, and clinical data were collected using structured questionnaires. A total of 422 dental caries-suspected patients were selected and coronal caries scraps were collected by the dentist aseptically; these samples were transported to a microbiological laboratory to identify the antibiotic sensitivity assay and biofilm formation by the isolated pathogens. The data was analyzed using SPSS version 22. The P value of ≤0.05 was considered statistically significant. Results The overall prevalence of culture-positive samples was found to be 196 (46.4%). From the 196 culture-positive samples, 327 bacteria were isolated. Out of 327 bacterial isolates, 196 (46.4%) were identified as Streptococcus mutans and 69 (35.2%) were identified to be Staphylococcus aureus. From the isolated bacteria, 311 (95.1%) organisms were identified as positive for biofilm formation. From the AST assay, we have identified that penicillin has the highest resistance rate of 76.5%, followed by tetracycline at 64.8%. In contrast, the antibiotics such as cefoxitin and chloramphenicol have a sensitivity of 83.5% and 81.6% to all the bacterial isolates. The overall prevalence of multidrug resistance (MDR) in the isolates was found to be 40.4%. With respect to the associated risk factors, the white spot (AOR = 3.885, 95% CI 1.282-11.767, P = 0.016), gum bleeding (AOR = 2.820, 95% CI 1.006-7.907, P = 0.049), toothache (AOR = 2.27, 95% CI 0.58-0.885, P = 0.033), and chocolate consumption (AOR = 5.314, 95% CI 1.760-16.040, P = 0.003) were statically associated with dental caries bacterial infection. Conclusion Based on our findings, we recommend the integration of routine culture and AST into clinical practice that might support the diagnosis and management of MDR in dental caries. The education on proper dietary habits might support the prevention and control of dental caries. It is important to provide health education on how to improve oral health in the study area. The education on proper dietary habits might support the prevention and control of dental caries. Further study is needed to find the other determinant factors of dental caries.

In Vitro Assessment of Probiotic and Technological Properties of Lactic Acid Bacteria Isolated from Indigenously Fermented Cereal-Based Food Products

The present study concerns the isolation and characterization of potential probiotic bacteria isolated from indigenously fermented cereal-based products commonly produced by tribal people of the Aravali hills region of India and the documentation of their unexplored probiotic attributes. The isolated strains were evaluated for probiotic attributes, such as bile salt and acid tolerance, lysozyme and phenol tolerance, antagonistic and antifungal activity, cell autoaggregation, cell-surface hydrophobicity, simulated gastric and pancreatic digestion, antioxidative potential, bile salt hydrolase activity, and H2O2 production. The safety of isolates was assessed by antibiotic sensitivity, hemolytic activity, DNase activity, and biogenic amine production assays, while technological properties, such as fermenting ability, amylolytic activity, and EPS production, were also evaluated. A total of 70 LAB isolates were screened initially, and 6 strains showed good potential as probiotic candidates in in vitro assessments. The efficient strains were identified using phenotyping and biochemical characterization, which results were further confirmed and recognized at the strain level using phylogenetic analysis and 16S rDNA sequencing. The current study has shown that Lactiplantibacillus plantarum KMUDR7 isolated from “Makka ki Raab” has excellent probiotic attributes and could be a potential probiotic for product preparation. However, other strains, Lactobacillus delbrueckii subsp. bulgaricus KMUDR1 and Lacticaseibacillus rhamnosus KMUDR9, showed good properties, while KMUDR14, -17, and -20 also have comparable probiotic attributes.

Isolation and Identification of H. pylori among Iraq patients with chronic gastric inflammation

Background: H. pylori is one of the gastrointestinal organisms in which more than half the world's population was infected. The aim of this study was to Isolation, identity, and determine antibiotic susceptibility of H. pylori from samples of the patient (biopsies) using various procedures. Patients and methods: A total of 90(58 males, 32females) patients with different age groups from both genders are involved in this study suffering from dyspeptic symptoms They underwent diagnostic ‘upper’ gastrointestinal (G.I.) endoscopy at “Endoscopy unit of AL- Sadder Teaching Hospital in Baghdad “during the period November 2021 to March 2022. Results: The results showed a relationship between H. pylori infection occurrence and endoscopic ally diagnosed dyspeptic patients; it was recorded that H. pylori was isolated in 30 cases. Antibiotic resistance test for H. pylori isolates showing susceptibility to levofloxacin, clarithromycin, ciprofloxacin, and amoxicillin. Whereas all the tested isolates were appearing resistant to metronidazole, and tetracycline. Conclusion: The results showed a relationship between H. pylori infection occurrence and endoscopic ally diagnosed dyspeptic patients. Culture and antibiotic sensitivity assay for detection of H. pylori are more reliable in biopsies than urease tests. H. pylori isolates were sensitive to levofloxacin, clarithromycin, ciprofloxacin, and amoxicillin.

Detection via in vitro amplification of lasR gene associated with virulent attribute of Pseudomonas aeruginosa from acute pulmonary infections

Pseudomonas aeruginosa is the most ubiquitous pulmonary pathogen of human which causes successfully unscrupulous infections in patients with the suppressed immune system of every age group and is considered as the first or second key pathogen in the research. The most lethal and persistent pathogen that caused the acute ventilator-acquired pneumonia (VAP) infection is P. aeruginosa. The Quorum sensing (QS) system is present in P. aeruginosa which regulates the expression of various virulence factors. In the current study, the contribution of lasR gene of pathogenic P. aeruginosa responsible for acute pulmonary infections was investigated. The objectives of the current work were; to screen the pathogenic P. aeruginosa from acute (VAP) through endotracheal tract (ETT) secretions and blood, to identify and characterize pathogenic strains by biochemical testing and virulence assays and to detect lasR, gene of P. aeruginosa responsible from acute pulmonary infections. The samples included secretions (Endotracheal tract) and Blood samples from patients with acute Ventilator-associated pneumonia (VAP). Samples were provided by the Microbiology laboratory of GCU Lahore. Total four strains of P. aeruginosa were selected as most virulent after confirmatory test of antibiotic sensitivity and virulence assays. Mutation was induced in wild strains via ethidium bromide. Molecular characterization of P. aeruginosa strains and lasR gene was done. Sequence analysis results after BLAST at NCBI confirmed P. aeruginosa strains and the presence of lasR gene which is involved in multiple virulence factors and is responsible for acute pulmonary infections. Wild and mutant strains of this bacterium showed resistance to the most commonly used antibiotics. Hence, it can be concluded that P. aeruginosa is involved in hospital-acquired and ventilator-acquired pneumonia and is a highly efficient multidrug-resistant pathogenic bacteria. Also, lasR gene sequence can be used as the diagnostic marker to identify the virulent lasR gene sequence from this opportunistic pathogen in the future.

Detection of extended-spectrum β-lactamase (ESBL) producing Escherichia coli in chickens

Objective: Indiscriminate use of antibiotics in poultry farms increases the chance of antibiotic-resistant and ESBL producing bacteria in Bangladesh. Therefore, the study was undertaken to detect the extended-spectrum β-lactamase (ESBL) producing Escherichia coli (E. coli) in chickens. 
 Materials and methods: A total of 60 cloacal swab samples (20 from commercial layer, 20 from commercial broiler, and 20 from commercial Sonali chickens) were collected from the Rajshahi district of Bangladesh. The E. coli was isolated from these samples and identified based on cultural, staining, and biochemical characteristics. The disk diffusion method was used to assay the antibiotic-resistant/sensitivity patterns of the isolated E. coli. Phenotypic detection of ESBL producing E. coli was also done. 
 Results: The prevalence of E. coli in chickens was 61.67% in the Rajshahi district of Bangladesh, where the prevalence was 60%, 60%, and 65% in a commercial layer, commercial broiler, and commercial Sonali chickens, respectively. The antibiotic sensitivity assay of E. coli isolated from commercial layer chickens showed 100%, 80%, 50%, 40%, and 40% resistant to amoxicillin, tetracycline, cefotaxime, ciprofloxacin, and ceftazidime, respectively. E. coli isolated from commercial broiler chickens showed 100%, 100%, 60%, 50%, and 40% resistant to amoxicillin, tetracycline, cefotaxime, ceftazidime, and ciprofloxacin, respectively. E. coli isolated from commercial Sonali chickens showed 90%, 70%, 50%, 50%, and 40% resistant to amoxicillin, tetracycline, cefotaxime, ciprofloxacin, and ceftazidime, respectively. In phenotypic detection, the overall prevalence of ESBL producing E. coli was 43.33%, where 40%, 50%, and 40% in the commercial layer, commercial broiler, and commercial Sonali chickens, respectively in the Rajshahi district of Bangladesh. 
 Conclusion: These results indicated that chickens are a potential reservoir for ESBL producing E. coli and their antibiotic resistances are obviously significant. These findings will help us to make a proper guideline for the treatment, prevention, and control of E. coli prevalent in chickens in Bangladesh

ANTIBIOTIC-RE¬¬SISTANT MOTILE AEROMONADS ASSOCIATED WITH CULTURED INDIAN MAJOR CARPS, POND WATER AND POND SEDIMENT

The uproar in antimicrobial resistance (AMR) among the aquacultured environment has led to the isolation of multiple antibiotic-resistant (MAR) Aeromonas strains. The current study aimed at the enumeration of antibiotic-resistant Aeromonas in carps of aquacultured environment and market samples. Isolation of Aeromonas was also done in Rimler-Shotts agar supplemented with novobiocin followed by antibiotic-sensitivity assay against 12 broad-spectrum antibiotics. Five oxytetracycline-resistant strains were examined for the presence of three tetracycline-resistant genes (tetA, tetC and tetE). The presumptive Aeromonas counts on starch-ampicillin agar were determined as log 3.00-log 6.45/g in carps, log 3.00l-log 5.06/ml in pond water and log 3.30–log 5.14/g in pond sediment. Higher proportions of motile aeromonads from market carps were resistant to chloramphenicol, cefalexin, gentamycin, oxytetracycline and trimethoprim than the farmed carps. Aeromonas strains depicted 57 resistant profiles. About 88.43% of the Aeromonas strains were of the MAR group among which 12.15% and 4.67% were resistant to ≥6 and ≥7 antibiotic groups, respectively. Selected oxytetracycline-resistant strains were negative for targeted genes. The current study implied the high prevalence of AMR bacteria in cultured carps in West Bengal, India. Furthermore, the study indicated that motile aeromonads comprise an effective marker for monitoring AMR in freshwater aquatic environments.

Antibacterial Performance Evaluation of Silver Coated River Sand for Water Decontamination Application

The presence of microbes in drinking water is a serious health hazard demanding immediate attention. Silver is known for centuries for its highly effective antimicrobial properties against a variety of microorganisms. Sand is a natural filter media that is widely used in water purification systems for the removal of dirt and suspended matter from water. Hence the development of additional antimicrobial features in commonly used filter material i.e. sand by coating with silver is an alternative technology for providing a safe drinking-water free from microbes. The present study was performed to develop a cost-effective material with antimicrobial properties by coating locally available river sand with silver. The coated material was subsequently used for its antimicrobial performance by using standard methods. To perform the tests E.coli was isolated from wastewater by using standard microbiological protocols. Thereafter, a biochemical test and antibiotic sensitivity assay were performed. Synthesised silver-coated sand was tested for its antibacterial activity against E.coli through the agar well diffusion method. The results showed a zone of clearance ≥40 mm with 700 mg of synthesised sample. To further determine the efficacy of developed material against E.coli load in artificially contaminated water, experiments were conducted by passing contaminated water through the material stuffed inside a hollow tube filter. A colony count reduction of 86.67 per cent was observed on passing 1000 ml of 3x103 CFU/ml contaminated water through the filter. The present study suggests that additional functionality of microbial reduction can be introduced in the sand through the silver coating. The developed material can be effectively used for the removal of fecal coliforms (E.coli) present in water bodies at an effective cost in addition to the removal of traditional impurities like dirt and suspended materials.