Kirby-Bauer Disc Diffusion Method Research Articles

Prevalence of Antimicrobial Resistant Escherichia coli from Sinking Creek in Northeast Tennessee.

Antibiotic resistance (AR) is a critical global health threat exacerbated by complex human-animal-environment interactions. Aquatic environments, particularly surface water systems, can serve as reservoirs and transmission routes for AR bacteria. This study investigated the prevalence of AR E. coli in Sinking Creek, a pathogen-impacted creek in Northeast Tennessee. Water samples were collected monthly from four sites along the creek over a 6-month period. E. coli isolates were cultured, identified, and tested for susceptibility to eight antibiotics using the Kirby-Bauer disk diffusion method and broth disk elution method for colistin. Data were analyzed to determine the prevalence of AR and multidrug resistance (MDR) among isolates. Of the 122 water samples, 89.3% contained E. coli. Among the 177 isolates tested, resistance was highest to ciprofloxacin (64.2%) and nitrofurantoin (62.7%), and lowest to fosfomycin (14.1%) and colistin (6.0%). Significant differences in resistance to ceftriaxone and amoxicillin/clavulanic acid were observed between sampling sites. MDR was prevalent in 47.5% of isolates, with 5.1% resistant to seven antibiotics. The most frequent MDR patterns (6.8%) included three antibiotics: ceftriaxone, ciprofloxacin, and nitrofurantoin. The high prevalence of AR E. coli in Sinking Creek poses a significant public health risk, highlighting the need for ongoing surveillance and intervention strategies to prevent the spread of AR bacteria.

Isolation of Nutmeg Essential Oil (Myristica fragrans houtt) From Aceh Indonesia and Their Antioxidant and Antibacterial Activities

This study aims to isolate the nutmeg essential oil (Myristica fragrans Houtt) from Aceh Indonesia and evaluate their biological activity. The antioxidant activity of the nutmeg essential oils (Myristica fragrans Houtt) was determined by DPPH (1,1-difenil-2-pikrihidrazil) assay. The DPPH assay showed that arillus essential oil (AMFH) has the highest antioxidant activity with the IC50 values was 216,695 ppm. The chemical composition of the AMFH was perfomed by Gas Chromatography-Mass Spectroscopy (GC-MS), and the results showed that AMFH contains Terpinen-4-ol (T-4-ol), α-Terpineol (α-T), Safrole (Saf) and Myristicin (Myr) with the percentage area of 11.20%; 1.83%; 5.10%; and 27.80% respectively. The AMFH was isolated by column chromatography and four fractions were obtained, namely AMFH1; AMFH2; AMFH3; and AMFH4 fractions. The DPPH assay showed that the AMFH3 fraction showed excellent antioxidant activity with the IC50 values of 59.329 ppm. The AMFH3 fraction was than reisolated by using by column chromatography to obtain four subfractions namely AMFH3A; AMFH3B; AMFH3C; and AMFH3D. The DPPH assay showed that the subfraction of AMFH3A has the highest antioxidant activity with the IC50 values of 98.993 ppm. The antibacterial activity of AMFH3A subfractions was evaluated by Kirby Bauer-Disc diffusion method, and the results showed that AMFH3A subfraction showed slightly higher activity against Staphylococcus epidermidis and Staphylococcus aureus with the diameter inhibition of 14.28 mm and 12.26 mm respectively. The chemical composition of the AMFH3A subfraction was performed by GC-MS, and the results showed that AMFH3A subfraction contains Terpinen-4-ol (T-4-ol), α-Terpineol (α-T), Safrole (Saf) and Myristicin (Myr) with the percentage area of 14.37%; 2.16%; 7.36%; and 54.77% respectively.

ANTIBACTERIAL EFFICACY OF BACTERIOPHAGES AGAINST VIBRIO CHOLERAE

This study investigates the use of bacteriophages as an alternative antibacterial approach to combat antibiotic-resistant Vibrio cholerae, a major public health concern. Vibrio cholerae strains were identified through culture on TCBS agar, microscopy, and biochemical tests (catalase, oxidase, indole, and citrate). Antibiotic susceptibility was assessed using the Kirby-Bauer disk diffusion method across five antibiotics: tetracycline, norfloxacin, ampicillin, ciprofloxacin, and erythromycin. Results showed resistance to ampicillin, tetracycline, and erythromycin, while strains remained susceptible to norfloxacin and ciprofloxacin Five bacteriophages against Vibrio cholerae were isolated from 50 wastewater samples, and only two (F1 and F2) showed lytic activity, forming clear plaques. These two lytic phages were further purified and characterized for stability across different temperatures, pH levels, and host range. The isolated phages were tested for host range against six Vibrio cholerae strains, with F1 lysing five strains and F2 lysing three, and demonstrated stability across temperatures (20°C to 55°C) and pH levels (4 to 9). They remained active across a wider temperature and pH range demonstrating their potential for therapeutic use. The study shows that these phages are highly specific, targeting only Vibrio cholerae strains from various sources without affecting other bacterial species. This specificity makes them safer for therapeutic use, as they are less likely to disrupt the body’s natural bacterial flora. Further genomic studies are recommended to characterize the genetic makeup of these phages, optimizing their application in cholera treatment. This study provides critical insights into the potential of bacteriophages as an alternative treatment for antibiotic-resistant Vibrio cholerae.

Antimicrobial Susceptibility Patterns of Bacteria Associated with Upper Respiratory Tract Infections in North and South Waziristan, Pakistan

Background: Upper respiratory tract infections (URTIs) are a significant cause of outpatient visits globally, with antimicrobial resistance (AMR) presenting a growing challenge to effective treatment. In Pakistan's tribal regions, limited healthcare access exacerbates this issue.Objective: To determine the prevalence of bacterial pathogens causing URTIs and assess their antimicrobial susceptibility patterns in North and South Waziristan, Pakistan.Methods: This cross-sectional study involved 300 throat swabs collected from outpatients between January and June 2023. Samples were inoculated on Blood, MacConkey, and Chocolate agars, followed by incubation at 37°C for 24 hours. Standard biochemical tests were used for bacterial identification, and the Kirby-Bauer disc diffusion method assessed antimicrobial susceptibility. Statistical analysis was performed using SPSS version 25.0, with p-values ≤ 0.05 considered significant.Results: Pathogens were isolated in 93% of samples, with Staphylococcus aureus (40.2%), viridans group streptococci (35.7%), and Streptococcus pyogenes (17.1%) being the most common. Resistance was highest in viridans group streptococci (33.7% to tazobactam) and lowest in Streptococcus pyogenes (26.3%).Conclusion: The high rates of resistance, particularly in viridans group streptococci, highlight the need for targeted interventions to mitigate AMR in this region.

Physicochemical characteristics and antibiotic resistance patterns of enteric bacteria isolated from harvested rainwater (HRW) in Oraukwu, Anambra State, Nigeria

infections temperature, colour, turbidity, DO, TDS, TSS, alkalinity, hardness, chloride, and some heavy metals of the water samples were examined using APHA method. Bacteriological analyses were performed using the membrane filtration technique. Colonies formed were counted and expressed in CFU/100mL. Enteric bacteria were enumerated and characterized by their morphological characteristics and biochemical tests. Axenic cultures of the isolates were further subjected to antimicrobial susceptibility testing (AST) using the modified Kirby-Bauer disc diffusion method, based on the guidelines by CLSI. Results revealed that physicochemical parameters and some heavy metals were within acceptable limits, except for Fe (0.01-0.72 mg/L) and Pb (0.01-0.25 mg/L). Total bacterial counts ranged from 1.2×104 to 6.8×104 CFU/100mL, indicating high contamination. Morphological characteristics revealed twelve (12) isolates of enteric bacteria, comprising Escherichia coli (41.67%), Salmonella sp. (33.33%) and Shigella sp. (25%). All the isolates exhibited 100% resistant to augmentin and tetracycline, but showed varying degrees of susceptibilities; E. coli to levofloxacin (60%), Salmonella sp. to ertapenem, imipenem, levofloxacin and nalidixic acid (100%), and Shigella sp. to ceftriaxone and ertapenem (100%). ‘First flush’ diverters are recommended to be installed within the water collecting system, in order to divert runoff from the rooftop after a period of no rainfall. Antibiotics which the isolates were susceptible to are recommended for the treatment of infections caused by these pathogens.

Genetic and in-silico approaches for investigating the mechanisms of ciprofloxacin resistance in Salmonella typhi: Mutations, extrusion, and antimicrobial resistance

Salmonella enterica serovar Typhi spreads typhoid infection in humans through the consumption of contaminated food and water. Poor sanitation plays a pivotal role in its dissemination. Over time, the bacterium has acquired resistance to many promising antibiotics, posing a growing global health concern and hindering the achievement of sustainable development goals. This study aims to elucidate the molecular complexity of fluoroquinolone resistance, a first-line treatment for typhoid infection. To achieve this aim, 80 clinical isolates were collected from various diagnostic laboratories. These isolates were confirmed based on morphological characteristics and biochemical tests. Multidrug-resistant (MDR) and extensively drug-resistant (XDR) isolates were identified using the Kirby-Bauer disc diffusion method. The mechanism of ciprofloxacin resistance was investigated by sequencing the quinolone resistance-determining region (QRDR) genes and identifying the presence of the qnrS1 gene. As a result of this study, 60 % of isolates showed resistance to ciprofloxacin. At the same time, the qnrS1 gene was present in all the selected strains while mutation analysis identified significant mutation in QRDR of DNA gyrase subunit A (gyrA) and Topoisomerase IV (parC) gene. The combinatorial effect was further investigated by downloading 286 draft genomes. The Mutation analysis reveals significant mutations at gyrA S83F, gyrA D87N, gyrA S83Y, gyrB S464F, parC S80I, and parE L416F. Additionally, docking analysis indicates reduced binding affinity and altered solvent accessibility, which show the structural changes at mutation sites. This study provides crucial insights that mutation reduces the binding affinity while qnrS1 acts as a transport channel to extrude the ciprofloxacin. In the future, further validation through experimental mutagenesis is recommended, for targeted therapeutic interventions against the mounting threat of antibiotic-resistant S. Typhi.

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

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

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

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

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

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

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

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

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

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

Assessment of Bacterial Contamination in Used Cosmetic Contact Lenses Among Women Visiting Beauty Salons in Sabratha City

This study aimed to assess bacterial contamination in cosmetic contact lenses used by women visiting beauty salons in Sabratha city and to evaluate the antibacterial susceptibility of the isolated bacteria. A total of 50 used soft cosmetic contact lenses and 5 new (unused) lenses were collected in April 2023. The lenses were swabbed, and samples were incubated in nutrient broth for bacterial isolation, followed by streaking on different agar plates (nutrient agar, MacConkey agar, and blood agar). Antibiotic susceptibility was tested using the Kirby-Bauer disk diffusion method, with various antibiotics. The results showed that all 5 unused lenses were free from contamination, while 43 out of 50 used lenses (86%) exhibited microbial contamination. The most commonly isolated bacteria were Pseudomonas aeruginosa (35%), Staphylococcus epidermidis (25%), and Staphylococcus aureus (15%), along with other species (11%). Antibiotic susceptibility testing revealed that Ciprofloxacin, Cefotaxime, Ceftriaxone, and Imipenem had the highest antibacterial effectiveness, with inhibition zones ranging from 26 mm to 30 mm. Gentamycin, Amikacin, and Tobramycin showed moderate effectiveness, while Cefuroxime and Augmentin had lower effectiveness. Cloxacillin showed no antibacterial activity. The findings emphasize the high risk of bacterial contamination in cosmetic contact lenses, stressing the importance of maintaining strict hygiene practices to prevent eye infections. Proper disinfection and storage in sterile solutions are crucial for ensuring lens safety and longevity, while effective antibiotic treatments are necessary to control bacterial contamination.

Microbiological profile and antibiotic susceptibility pattern of chronic dacryocystitis at a tertiary eye care centre in Western India

: Chronic dacryocystitis is a low-grade infection &amp; inflammation of the lacrimal sac. If neglected the infection may extend to surrounding orbit, brain and paranasal sinuses leading to sight and/or life-threatening complications. Thus appropriate, effective and timely antibiotic treatment/ prophylaxis is desirable. The present study was aimed to document the current microbiological profile and antibiotic susceptibility in adult patients of chronic dacryocystitis seen at our tertiary eye care centre in western India.The study was a cross-sectional, prospective, observational study. The study included 60 adult patients of chronic dacryocystitis. In every case two samples from the lacrimal sac collected via the regurgitation technique or by lacrimal passage syringing were sent for microbiological evaluation. Gram staining was used for identification of bacterial pathogen. KOH mount was used for identification of fungi. The second swab was used for performing culture -sensitivity. The Clinical and Laboratory Standard Institute Guidelines were used to know the antimicrobial sensitivity. Kirby-Bauer disk diffusion method was used for this purpose. The statistical analysis was done using descriptive statistics as mean, standard deviation, median and percentages. Microsoft excel worksheet was used. 60 samples were taken. 53/60 (88.3%) samples showed microbial isolates after 24-48 hours of incubation. 78.3% were gram positive organisms and 10% were gram negative organisms. The most common gram-positive organism was (68.3%) and the most common gram-negative organism was (8.3%). Amongst the antibiotics the most sensitive antibiotic was Ampicillin + Sulbactam (92.5%) and the most resistant antibiotic was Ciprofloxacin (3.8%). The antibiotic most sensitive to gram positive organisms was Ampicillin and Sulbactam, Cephalexin, Linezolid, Cloxacillin and Vancomycin. The antibiotic most sensitive to gram negative organisms was Gentamicin, Amikacin, Gatifloxacin, Ceftazidime, Meropenem and Polymixin -B. The current microbiological profile and antibiotic susceptibility of the microorganisms responsible for chronic dacryocystitis is an invaluable tool in the treatment of chronic dacryocystitis with the most appropriate and effective antibiotic.

Distribution of chaperone-usher fimbriae and curli fimbriae among uropathogenic Escherichia coli

BackgroundIn the present study, we aimed to determine the frequency of the csgA, fimH, mrkD, foc, papaGI, papGII and papGIII genes, to provide and to design fimbrial adhesin gene (FAG) patterns and profiles for the isolated uropathogenic Escherichia coli (UPEC) strains.MethodsThe enrollment of 108 positive urine samples was performed during seven months, between January 2022 and July 2022. The UPEC strains were confirmed through the standard microbiological and biochemical tests. The antimicrobial susceptibility test was performed through the Kirby–Bauer disc diffusion method. Molecular screening of FAGs was done through the polymerase chain reaction technology. The statistical analyses including chi square and Fisher’s exact tests were performed to interpret the obtained results in the present study.ResultsAs the main results, the antimicrobial resistance (AMR) patterns,multi- (MDR) and extensively drug-resistance (XDR) patterns and FAG patterns were designed and provided. fimH (93.3%), csgA (90.4%) and papG (37.5%) (papGII (30.8%)) genes were recognized as the top three FAGs, respectively. Moreover, the frequency of csgA-fimH gene profile was identified as the top FAG pattern (46.2%) among the others. The isolates bearing csgA-fimH gene profile were armed with a versatile of phenotypic AMR patterns. In the current study, 27.8%, 69.4% and 1.9% of the UPEC isolates were detected as extended-spectrum ß-lactamases (ESBLs) producers, MDR and XDR strains, respectively.ConclusionsIn conclusion, detection, providing and designing of patterns and profiles in association with FAGs, AMR feature in UPEC strains give us an effective option to have a successful and influential prevention for both of UTIs initiation and AMR feature.

Diarrhoeagenic Escherichia coli associated with childhood diarrhoea in Osun state, Nigeria

IntroductionDiarrhoea is a major public health concern in developing countries, usually exacerbated by poor water, sanitation and hygiene but its aetiology is under-studied, particularly away from capital cities. We identified diarrhoeagenic Escherichia coli (DEC) from stools collected in Ile-Ife and Ilesa, Osun state, Nigeria and determined their antibiotic resistance profiles.MethodsStool samples from 167 children with diarrhoea and 334 controls under the age of 5 years were cultured for Escherichia coli and Salmonella. Bacterial isolates were identified biochemically and DEC were identified by PCR. Antimicrobial susceptibility testing was by modified Kirby-Bauer disc diffusion method in accordance with the CLSI guidelines. Data were analyzed using Chi-square and Fisher’s exact tests.ResultDiarrhoea infection is significantly high among children under 12 months (p = 0.002), caregivers without at least primary school education (p = 0.006), breastfeeding for under 6 months (p˂0.001), and caregivers who were siblings (p = 0.004). DEC was detected in 69(41.3%) cases but only 86(25.7%) controls (p < 0.001) and more commonly recovered during the wet season (p < 0.001). Enterotoxigenic E. coli (p = 0.031), enteropathogenic E. coli (p = 0.031) and Shiga-toxin-producing E. coli (p = 0.044) were recovered more commonly from cases than controls. DEC from patients with diarrhoea were commonly resistant to sulphonamides (91.3%), trimethoprim (82.6%), and ampicillin (78.3%) but were largely susceptible to quinolones and carbapenems (97.1%).ConclusionEnteropathogenic, enterotoxigenic and Shiga toxin-producing E. coli are associated with diarrhoea in our setting, and show considerable resistance to first-line antimicrobials. Risk factors for DEC diarrhoea include infancy, inadequate breastfeeding and caregivers with education below primary school.

Resistance Genes and Mortality in Carbapenem-resistant Klebsiella pneumoniae Bacteremias: Effects of the COVID-19 Pandemic

Emerging carbapenem-resistant Klebsiella pneumoniae (K. pneumoniae) (CRKP) bacteremias are presenting significant public health risks due to limited treatment options and increased mortality. K. pneumoniae isolates exhibit carbapenem resistance rates that vary from 25% to 50% throughout the European continent, including our country. To assess the characteristics of CRKP bacteremia, a condition that has recently demonstrated an increasing prevalence in our center. We sought to ascertain the resistance rates of isolated strains to antibiotics other than carbapenems, identify the responsible carbapenemase genes, evaluate the efficacy of antibiotics, determine mortality rates, explore clonality among strains, and investigate the influence of the COVID-19 pandemic on all these factors. Retrospective observational study. This study included patients aged 18 and older who had experienced meropenem-resistant K. pneumoniae bacteremia. Meropenem resistance was confirmed by employing the Kirby-Bauer disk diffusion method. Meropenem minimum inhibitory concentration (MIC) levels were determined using the gradient test, while colistin MIC levels were ascertained using the disk elution technique. Carbapenemase genes were evaluated via colony polymerase chain reaction (PCR), and clonality analysis was performed using the arbitrarily primed PCR technique. The study comprised 230 patients, with a mean age of 63.1 ± 15.9 years, of whom 58.7% were male. Oxacillinase-48 (OXA-48) was detected in 74.8% of the patients, New Delhi metallo-beta-lactamase (NDM) in 12.6%, OXA-48 + NDM in 7.8%, and KPC in 4.8%. The 14-day and 30-day mortality rates were 57% and 69.6%, respectively. Multivariate analysis of the 30-day mortality revealed several crucial factors, including bacteremia development in the intensive care unit, the occurrence of bacteremia during the COVID-19 pandemic, polymicrobial bacteremia, the use of indwelling intravenous catheters, a platelet count of ≤ 140,000/μl, procalcitonin levels of ≥ 6 μg/l, and a Charlson comorbidity score ≥ 3. Notably, the OXA-48 and KPC genes were upregulated significantly during the COVID-19 pandemic, while the NDM gene groups were downregulated. Additionally, both 14-day and 30-day mortality rates increased significantly. In this study, the most prevalent carbapenemase gene was OXA-48; however, there has been a recent increase in KPC genes. No dominant epidemic strain was identified through clonality analysis. The clustering rate was 68% before the pandemic, increasing to 85.7% during the pandemic. The significance of infection control measures is underscored by the rise in both clustering and mortality rates during the COVID-19 pandemic.

AN UPDATE ON CURRENT STATUS OF ANTIBIOTIC RESISTANCE IN SALMONELLA TYPHI: A RETROSPECTIVE ANALYSIS OF BLOOD CULTURE REPORTS FROM A TERTIARY CARE HOSPITAL

Background: Pakistan bears most of the burden of drug-resistant typhoid, challenging its healthcare systems with substantial cost. This study’s purpose is to investigate resistance in community-acquired salmonella typhi to guide its evidence-based empiric treatment. Methods: This study used retrospective data from the microbiology laboratory, Khyber Teaching Hospital, Peshawar (September 2022-March 2023). Data of routine diagnostic samples for typhoid was retrieved from the database. Kirby–Bauer disk diffusion method was employed to determine the sensitivity of S. Typhi against a panel of 21 selected antibiotic discs (not exclusively for each isolate). Results: Among 1742 suspected patients, 239 (13.92%) were positive for S. Typhi with 212/238 (89.1%), 227/233 (97.4%), and 196/239 (82.0%) isolates resistant to chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole, respectively. High resistance (88.0% to ciprofloxacin) was detected against fluoroquinolones. Third-generation cephalosporins also showed poor activity with 144/158 (91.1%) and 120/136 (88.2%) resistance towards ceftriaxone and cefixime, respectively, except for cefoperazone/sulbactam (2/123, 1.6%). Among 157 tested isolates, 3 (1.9%), 9 (5.7%), and 123 (78.3%) were labeled as non-resistant, MDR, and XDR strains, respectively. XDRs were less resistant to azithromycin (1/114), piperacillin/tazobactam (1/123), carbapenems (0/123), and tigecycline (0/123). Conclusion: XDR S. Typhi was observed as the dominant strain in Peshawar regions for which azithromycin is still the drug of choice. With emerging resistance, azithromycin safety should be ensured through antibiotic stewardship principles. An interesting finding was the enhanced activity of cefoperazone/sulbactam, suggesting future studies. Alternative options are expensive antibiotics which can be used as a last resort. Keywords: Typhoid, Antibiotic resistance, Extensive drug-resistant (XDR) S. Typhi, Pakistan.

Preparation, in vitro and in silico antioxidant and antibacterial studies of 4-aminoacetanilide azo derivatives

A new series of new 4-aminoacetanilide azo derivatives 1–13 were successfully synthesised via a diazo coupling reaction and gave a good to excellent yield of 73 %–93 %. The antioxidant capabilities of the series 1–13 screened through 2,2′-diphenyl-1-picrylhydrazyl (DPPH) assay and ferric reducing antioxidant power (FRAP) assay showed promising data of 12.6–199.4 ppm and 12.65–210.9 mg/ml Trolox equivalent, respectively. The findings supported by in silico docking analysis targeted Heme oxygenase-1 (HO-1) evidenced by a binding score of – 7.2 to – 8.2 kcal/mol outperforming the standard, ascorbic acid scoring only – 5.7 kcal/mol. Among all, compound 11 displayed the highest antioxidant potential with IC25 of 12.6 ppm against DPPH assay and 210.9 mg/ml Trolox for FRAP assay believed owing to the presence of methoxy group at ortho position in the phenolic compound that effectively lowered the ionisation potential and high up energy of highest occupied molecular orbital (HOMO). Nevertheless, the antibacterial potential of the series screened through the Kirby-Bauer disc diffusion method against Escherichia coli and Staphylococcus aureus showed no antibacterial activity postulated due to the presence of amide and acetyl group restricted the ability of the compound to form an interaction with the protein receptor of bacteria tested. This study provided new insight into the development of dual-functional drugs for non-communicable diseases and antimicrobial resistance.

Antimicrobial resistance profiles of and associated risk factors for Pseudomonas aeruginosa nosocomial infection among patients at two tertiary healthcare facilities in Lusaka and Copperbelt Provinces, Zambia.

Antimicrobial resistance (AMR) of pathogens such as Pseudomonas aeruginosa is among the top 10 threats to global health. However, clinical and molecular data are scarce in Zambia. We, therefore, evaluated the AMR profiles of P. aeruginosa nosocomial infections (NIs). A year-long hospital-based cross-sectional study was conducted at two large tertiary-level hospitals in Zambia. Patients with current or previous hospital contact were screened for NIs. The current study focused on patients diagnosed with P. aeruginosa NIs. Clinical specimens were collected for bacteriological culture, and PCR amplification of 16S rRNA gene fragments was performed on pure isolates. Hospital or NIs were defined as infections that arise during hospitalization, occurring at least 48 h after admission. The Kirby-Bauer's disk diffusion method was used to evaluate antibiotic resistance patterns. The association between AMR and risk factors was analysed using the χ2 test. Eight hundred and forty-one patients were screened, and clinical specimens were collected and analysed. Of them, 116 (13.7%) were diagnosed with P. aeruginosa NIs. The participants' ages ranged from 15 to 98 years, with a mean of 51 (SD ± 18). Catheter-associated urinary tract infections (57%) were the most common, followed by pressure sores (38.7%). P. aeruginosa isolates were primarily susceptible to amikacin, which had the highest resistance to FEP. We observed a high prevalence of multidrug resistance (73.6%). The AMR was associated with carbapenem-hydrolysing β-lactamase gene blaOXA-51 and surgical care. This study has demonstrated that multidrug-resistant P. aeruginosa is prevalent in hospitals in Zambia's Lusaka and Ndola districts and possibly countrywide.

Presence of carbapenem resistance in hybrid Escherichia coli pathovars from ready-to-eat fresh-cut fruits in Accra, Ghana.

This study reports the presence of carbapenem-resistant Escherichia coli hybrid pathovars and its prevalence in 200 fresh-cut fruits from Accra. Standard culture methods were used to quantify microbial indicators and E. coli on fresh-cut fruits retailed in formal and informal outlets in Accra. The Kirby-Bauer disc diffusion method was used to determine the antibiotic resistance profile of E. coli, while multiplex PCR was employed to identify the virulence and carbapenem-resistance genes. Escherichia coli prevalence in cut fruits was 17%, with pawpaw, watermelon, and mixed fruit having higher prevalence than pineapple. Of the 34 E. coli isolates from fresh-cut fruits, 44% showed broad resistance to beta-lactam antibiotics, while 5.9% showed carbapenem resistance. The study identified virulence genes associated with all E. coli isolates, including stx1, stx2, escV, and ipaH, of which 97% were hybrid pathovars bearing genes for Shiga toxin-producing E. coli/enteropathogenic E. coli/enteroinvasive E. coli. The carbapenemase gene, blaIMP, was associated with both carbapenem-resistant E. coli phenotypes identified. Despite a low-carbapenem-resistance prevalence observed among E. coli isolates, hypervirulent hybrid strains of E. coli is present in fresh-cut fruits in the sampling area, posing a potential public health risk to fresh-cut fruit consumers.