Kirby-Bauer Disc Diffusion Method Research Articles

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.

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.

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

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.

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

This study reports the presence of carbapenem-resistant E. 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. E. coli prevalence in cut-fruits was 17%, with pawpaw, watermelon, and mix-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 STEC/EPEC/EIEC. 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.

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.

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.

Hypermucoviscous Klebsiella Pneumoniae Caused Community-Acquired Pneumonia in Gondar, Northwest Ethiopia.

The incidence of hypermucoviscous Klebsiella pneumoniae (hmvKp), which complicates community-acquired pneumonia, has been increasing recently. This study aimed to detect hypermucoviscous K. pneumoniae and determine its antimicrobial susceptibility pattern in adult patients with community-acquired pneumonia in Northwest Ethiopia. This cross-sectional study included 39 K. pneumoniae isolates identified by using Gram stain, culture, and biochemical tests from 312 adult patients with community-acquired pneumonia at the University of Gondar Comprehensive Specialized Referral Hospital from April to June 2021. The hypermucoviscous strains were identified by using the string test. Antimicrobial susceptibility testing was performed by using the Kirby-Bauer disk dif-fusion method. Data were entered by using EPI data version 4.6 and were analyzed by using SPSS version 20. A p-value ≤ 0.05 at a 95% confidence interval was considered statistically significant. Overall, 35.9% (n = 14) of the 39 K. pneumoniae isolates were hypermucoviscous phenotype. The mean age of the hmvKp group was lower than of the cKp group (36.93 ± 12.573 vs. 53.52 ± 19.556 years, p = 0.007). All hmvKp isolates were resistant to amoxicillin-clavulanic acid and trimethoprim-sulfamethoxazole. Azithromycin resistance in the hmvKp strains was significantly higher than in the cKp group (p = 0.012). This study demonstrates that the hmvKp phenotype causes community-acquired pneumonia and a full resistance to amoxicillin-clavulanic acid and trimethoprim-sulfamethoxazole. Antimicrobial resistance was higher in the hmvKp strain than in the classic strains. Further detection of resistance genes, capsular serotypes, hypermucoviscosity-related genes, and virulence genes is necessary.

Identification, Antibiotic Profiling of Potential Pathogenic Bacteria from Fomites in Neonatal Intensive Care Units in a Tertiary Teaching Hospital of North Karnataka

This study was taken up to determine the prevalence of potential pathogens in most touched fomites in Neonatal Intensive Care Units (NICUs) and to determine their antibiogram. Fifty swabs each were collected from fomites from In-born (for babies born in our center) and out-born (for babies born elsewhere, brought to our center) NICUs, before and after cleaning. Samples were processed using standard Microbiological techniques. Antibiogram was determined by Kirby-Bauer disc diffusion method. From In-born NICU, before cleaning, 42 (84%) samples yielded growth with 48 bacterial isolates of which 31 (64.6%) were pathogens and after cleaning, 40 (80%) samples yielded growth with 41 bacterial isolates, of which 30 (73.1%) were pathogens. Most frequent isolates were non-fermenting gram-negative bacilli (NFGNB) and Klebsiella pneumoniae before and after cleaning, respectively. Prevalence of bacteria from In-born NICU before and after the cleaning was statistically significant (p = 0.025). From Out-born NICU, before cleaning, 42 (84%) samples yielded growth with 45 bacterial isolates, of which 25 (55.55%) were pathogens. Samples collected after cleaning; 42 (84%) samples yielded growth with 43 bacterial isolates of which 19 (44.18%) were pathogens. Most frequent isolates were NFGNB and Klebsiella pneumoniae from In-born NICU and K. pneumoniae and Escherichia coli from Out-born NICU before and after cleaning, respectively. Overall prevalence of pathogens was significant (p = 0.007). Staphylococcal isolates were resistant to Methicillin. NFGNB exhibited highest resistance (55.9%) towards Gentamicin. Significant decrease in the frequency of pathogens after cleaning indicates stringent practice of sterilization protocol would be essential in hospital environment.

Molecular Evaluation of Aminoglycoside Resistance and Biofilm Formation Potential in Escherichia coli Isolates Collected from Hospitalized Patients

Background: Resistance to antibiotics and the ability to develop biofilms, two main virulence determinants of Escherichia coli, play a crucial role in the persistence of infections. Objectives: The aim of this study was to evaluate aminoglycoside resistance and biofilm formation potential in E. coli isolates collected from hospitalized patients in the Southwest of Iran. Methods: A total of 70 E. coli clinical isolates from different specimens were collected from Ahvaz teaching hospitals affiliated with Ahvaz Jundishapur University of Medical Sciences. All the isolates were identified as E. coli using conventional microbiological tests. Susceptibility to antibiotics was determined using the Kirby–Bauer disk diffusion method. Biofilm formation was assessed using the microtiter plate method. Finally, PCR was conducted to detect virulence gene determinants, including fimbrial genes, aminoglycoside modifying enzymes (AMEs), and 16S rRNA methylase (RMTase) genes. Results: Among aminoglycoside antibiotics, E. coli isolates showed the highest and lowest resistance rates to tobramycin (TOB; 51.4%) and gentamicin (GEN; 24.2%), respectively. Simultaneous resistance to GEN, amikacin, and TOB was observed in 28.5% of the isolates, representing the most common antibiotic resistance pattern. The prevalence of strong biofilm producers was higher in the extensively drug-resistant (XDR) phenotype group compared to the multiple drug-resistant (MDR) group (76.1% vs. 23.8%). Among the 36 isolates resistant to at least one of the aminoglycoside antibiotics, 36.1% had AME-related genes, either alone or in various combinations. Most isolates harboring AME genes were also positive for the presence of biofilm-related genes, including ecpA and fimA. Conclusions: The most frequent AME-related genes were ant(2”)-Ia and aph(3’)-Ia, followed by aac(3’)-IIa. The findings of the present study provide probable evidence that GEN is an effective aminoglycoside against biofilm-producing and antibiotic-resistant E. coli isolates.

Characterization of Diarrheagenic Escherichia coli and Salmonella enterica from Produce in the Chobe District of Botswana

Diarrheal disease is a leading cause of death in children in low- and moderate-income countries. Fresh produce, including fruits and vegetables, may harbor diarrheal disease-causing bacteria including strains of Salmonella enterica and Escherichia coli. This study aimed to determine the prevalence and antibiotic resistance profiles of S. enterica and E. coli isolated from produce samples (n = 207) obtained from retail markets in northern Botswana in Chobe District of Botswana in 2022. Samples were enriched in the appropriate selective media: Brilliant Green Bile Broth for E. coli and Rappaport Vassiliadis Broth for S. enterica. E. coli were confirmed by PCR detecting the phoA gene, and classified as potentially pathogenic through screening for the eae, stx, and stx2 and estIb genes. S. enterica isolates were confirmed using invA primers. Isolates were evaluated for resistance to ampicillin, amoxicillin-clavulanic acid, chloramphenicol, cefotaxime, doxycycline, streptomycin, sulfamethoxazole, and tetracycline antibiotic using the Kirby-Bauer Disk Diffusion method. E. coli was isolated from 15.5% of produce samples (n = 207). The gene eae was detected from 1.5% of samples, while stx1, stx2, and estIb were not detected. Resistance to one or more antibiotics was common (72%) with the majority of the resistant E. coli (n = 32) isolated from fruits (22%) and greens (18%) compared to other types of vegetables. Multidrug resistance (MDR, resistant to 3 or more antibiotics) was identified in 18% of samples. S. enterica was isolated from 3.4% of produce samples (7, n = 207). Resistance was uncommon among the S. enterica isolates (1/7). Overall prevalence of diarrheagenic S. enterica and E. coli was low; however, their presence and that of MDR E. coli in foods commonly consumed raw increases the risk to vulnerable populations. Strategies to reduce contamination of fresh produce and public education on washing and cooking some types of produce may be useful to reduce disease.

Streptococcus equi subspecies equi from strangles suspected equines: molecular detection, antibiogram profiles and risk factors

Strangles, caused by Streptococcus equi subspecies equi, is a highly infectious disease of equines causing major health issues and financial losses. The aim of the study was to detect the presence of the SeM gene in Streptococcus equi isolated from equine suspected of having strangles. A cross-sectional study design was conducted from July to December 2022 in five districts of the central Gondar zone, Ethiopia. One-hundred sixty swab samples were taken from animals that had been clinically suspected. The SeM gene was detected using polymerase chain reaction, and the antimicrobial susceptibility test was performed using the Kirby-Bauer disc diffusion method. The binary logistic regression model was employed to test for statistical significance. In 31.87% (51/160) of the samples, Streptococcus equi species were isolated, and 31.37% (16/51) of these species carried the SeM gene. There was a significant amount of tetracycline (81.5%), erythromycin (81.5%), and vancomycin (75.5%) resistance among the 16 isolates. Strangles were more likely to be present in animals who shared feed containers (AOR = 7.59; 95% CI = 1.44–39.93), drank from the same water troughs (AOR = 7.74; 95% CI = 1.44–41.01), and spent the night together (AOR = 5.97; 95% CI 1.41–25.37). The findings of this study showed that the research areas harboured Streptococcus equi subspecies equi. Sharing feed containers and water troughs were potential sources of strangles infection; thus, these containers need to be cleaned regularly.

Genetic Diversity, Virulence, and Antibiotic Resistance Determinants of Campylobacter jejuni Isolates in Romania

The emergence of antibiotic-resistant Campylobacter jejuni, a leading cause of gastroenteritis worldwide, presents a significant public health challenge requiring vigilant surveillance and disease control. This study aimed to characterize C. jejuni strains isolated in Romania from 2017 to 2020, focusing on genetic diversity, virulence, and antibiotic resistance determinants. The isolates underwent phenotypical testing, PCR, and antibiotic resistance assessment using the Kirby–Bauer disc diffusion method for ciprofloxacin, erythromycin, and tetracycline. Genetic analysis identified resistance and virulence genes, point mutations, and performed sequence typing (7-gene MLST) to determine genetic relatedness. Results indicated substitutions at position 86 in the amino acid sequence or position 257 in the nucleotide sequence of the gyrA gene in 47 fluoroquinolone-resistant isolates. Additionally, mutations in the rRNA 23S gene at positions 2074 and 2075, associated with macrolide resistance, were found in 12 of the 66 isolates. Allelic profiles generated 38 sequence types (STs), including three new STs not present in the reference database. The sequence data analysis revealed a genetically diverse C. jejuni population with a weak clonal structure. This study provides crucial insights into the genetic diversity and antibiotic resistance of C. jejuni strains in Romania, highlighting the need for ongoing surveillance and control measures.

Escalating Antibiotic Resistance in Uremia Patients Demands Urgent Global Action

Background: Uremia, a frequent complication of Chronic Kidney Disease (CKD), compromises immunity, increasing patients' susceptibility to bacterial infections. Multi-drug resistance (MDR) and extensively drug resistance (XDR) further exacerbate infection management challenges, particularly in regions with limited resources. Knowledge Gap: While bacterial resistance is well-documented globally, the prevalence and specific resistance patterns in uremia patients in Nasiriyah City remain underexplored. Aims: This study aimed to establish the prevalence and resistance profiles of MDR and XDR bacterial isolates among uremia patients in Nasiriyah City, with a focus on treatment implications and infection control strategies. Methods: A cross-sectional study was conducted at Al-Hussein Teaching Hospital from February 2023 to January 2024. One hundred samples from uremia patients were cultured and tested using the Kirby-Bauer disk diffusion method following CLSI guidelines. Results: The most frequently isolated bacteria were Escherichia coli (40%), Klebsiella pneumoniae (30%), Staphylococcus aureus (20%), and Pseudomonas aeruginosa (10%). High resistance rates were observed for Ampicillin (95%), Amoxicillin-Clavulanate (80%), and Ceftriaxone (75%), while resistance to Imipenem and Meropenem was lowest at 5% and 10%, respectively. Significant resistance patterns were noted across all tested antibiotics (P&lt;0.05). Novelty: This study provides the first comprehensive analysis of MDR and XDR bacterial prevalence in uremia patients in Nasiriyah City, highlighting the critical need for targeted antibiotic stewardship. Implications: The findings underscore the urgency of implementing stringent infection control measures and developing alternative therapeutic strategies to combat the rising threat of antibiotic resistance in this vulnerable population. The efficacy of carbapenems, though still relatively preserved, necessitates cautious use to prevent further resistance development. Highlights: High resistance to common antibiotics in E. coli and K. pneumoniae. Carbapenems remain effective, with low resistance rates. Urgent need for antibiotic stewardship and alternative treatments. Keywords: Uremia, Multi-drug resistance, Antibiotic susceptibility, Nasiriyah City, Infection control

Exploration of green catalytic Hantzsch process for synthesis of polyhydroquinoline derivatives and their in silico & in vitro evaluation as anti-tubercular agents

Polyhydroquinolines (PHQ) were long known for various pharmacological activities and numerous methods were reported for their synthesis by using different reaction conditions and catalysts. An attempt has been made to synthesize PHQs by following the environmental friendly green chemical approaches by using reusable and recyclable catalyst and solvent materials. Twelve compounds (2A-2L) were synthesized with varied substitutions on the aromatic ring by following the Hantzsch one-pot approach with bleaching earth clay and polyethylene glycol. Use of novel reaction conditions has improved the yield and drastically reduced the time required for the completion of the reaction. The DFT analysis revealed the structural features and the stability of the compound, and later the compounds were subjected to molecular docking against two key proteins of the M. tuberculosis H37 Ra InhA and DprE1. It was found that few of the compounds showed excellent binding interactions compared to the co-crystalized ligand. Later, all the synthesized compounds were subjected to the in vitro antimycobacterial activity using the Kirby-Bauer disk diffusion method, MICs were calculated by REMA assay and the hemolytic assay was performed to check cytotoxicity. Compounds 2K and 2E were found to show better inhibitory activity than the standard rifampin. The antimycobacterial activity of the PHQ compounds might be due to the interaction of the InhA and DprE1, which can be correlated positively and supported by the structural features and the in silico interaction data. Parallelly, molecular dynamic simulation studies were carried out with ligand 2K for the time frame of 100 ns against both targets InhA and DprE1 revealing the formation of stable complexes which further validate the ligand 2K as a potential lead molecule for further studies. The compounds can be further subjected to lead optimization for improved activity.

Surveillance of In Vitro Activity of Cefiderocol Against Carbapenem-Resistant Gram-Negative Clinical Isolates in a Tertiary Care Hospital.

Antibiotic resistance among Gram-negative bacterial isolates is increasingly observed. With the emergence of carbapenem-resistant and pan-resistant pathogens, treating these resistant infections is becoming more challenging due to the limited number of effective drugs. There is a desperate need for the discovery of new antibiotics with novel mechanisms of action. Cefiderocol is one such novel antibiotic with a unique siderophore-based mechanism of action, which has been recently approved for clinical use against drug-resistant pathogens. The present study aims to identify the in vitro activity of cefiderocol against major carbapenem-resistant clinical isolates, including those resistant to colistin. One hundred and one carbapenem-resistant clinical isolates were included in the study. Identification and antibiotic susceptibility testing were performed using the automated VITEK® 2 Compact (bioMérieux SA, Marcy-l'Étoile, France) identification and susceptibility testing system, except for colistin and cefiderocol. Colistin resistance in Enterobacterales and Pseudomonas aeruginosa was assessed using the agar dilution minimum inhibitory concentration method, while for Acinetobacter baumannii, broth microdilution method was employed. Cefiderocol susceptibility testing was conducted using the Kirby-Bauer disc diffusion method with 30 µg discs on standard Mueller-Hinton agar plates. For selected isolates, cefiderocol minimum inhibitory concentration detection was performed using broth microdilution with iron-depleted cation-adjusted Mueller-Hinton broth. Of the total 101 isolates, the majority (75, 74.25%) were Enterobacterales which includedKlebsiella pneumonia (42, 41.58%) and Escherichia coli (33, 32.67%), followed by Pseudomonas aeruginosa (13, 12.87%) and Acinetobacter baumannii (10, 9.9%). Only three (2.97%)of the isolates were Stenotrophomonas maltophilia. Most of the isolates were susceptible to cefiderocol, with only four (3.96%) isolates showing resistance. Colistin resistance was observed in six (6.12%) of the isolates. There was a good correlation between disc diffusion testing and broth microdilution testing for the detection of cefiderocol-resistant isolates. No cross-resistance with colistin was observed, as all colistin-resistant isolates were uniformly susceptible to cefiderocol Conclusion: Cefiderocol is highly effective with good in vitro activity against the majority of carbapenem-resistant pathogens. While some isolates do show resistance, it is relatively uncommon. Given its safety profile compared to colistin, cefiderocol can serve as an alternative to colistin to treat carbapenem-resistant infections and it may be considered even for the management of colistin-resistant cases. Disc diffusion testing is a reliable method for identifying cefiderocol-resistant isolates in routine clinical and diagnostic laboratories, especially in resource-limited settings.

Identification of novel drug targets to counteract efflux pump mediated multidrug resistance in Acinetobacter baumannii

The emergence of multidrug-resistant (MDR) Acinetobacter baumannii poses an escalating threat to the healthcare system worldwide. A significant factor contributing to increasing resistance is the overexpression of chromosomally encoded efflux pumps, which expel antibiotics from bacterial cells, thereby rendering treatments less effective. The efflux pumps not only mediate resistance to antibiotics through drug efflux but also work synergistically with other resistance mechanisms, thereby doubling the resistance. Despite their crucial role in antibiotic resistance, understanding of the structure, function, mechanisms of action, and regulation of efflux pumps remains limited, which is necessary for devising effective strategies to restore drug susceptibility and to combat MDR isolates. In this context, the present study evaluated the prevalence of efflux pump overexpression in clinical A. baumannii isolates using phenotypic and genotypic methods and identified potential therapeutic targets employing a network-based approach. A total of 172 A. baumannii isolates were collected and subjected to antibiotic susceptibility tests using the Kirby-Bauer disk diffusion method. All the isolates were found to be MDR, with 94.76 % showing resistance to carbapenems. Efflux pump overexpression was detected in 54.65 % of isolates using the Ethidium-Bromide Agar Cartwheel method, and efflux pump inhibitory activity was observed in 68.71 % of isolates using cyanide m-chlorophenylhydrazone (CCCP). A total of thirteen efflux pump genes were detected in the tested isolates using diagnostic PCR, which were considered for interaction network analysis using STRING. Clustering analysis of the merged network identified two highly interconnected clusters, each comprising functional partners crucial for efflux pump function and regulation. Key hub genes, including AdeB, AdeJ, AdeK, AdeC, macB, tolC, AIL80285.1, AdeR, and AdeS, were identified as primary targets due to their significant influence on the network. Additionally, 24 clustered genes were pinpointed as potential drug targets for developing novel therapeutics to combat the formidable challenge of efflux pump-mediated MDR in A. baumannii.

Occurrence and Antibiotic Resistance Profiles of Metallo Beta Lactamase Producing Pseudomonas aeruginosa among Clinical Isolates in Enugu Metropolis, Nigeria

Introduction: Antibiotic resistance is rising worldwide, posing a challenge for contemporary medicine. Metallo-beta-lactamases (MBLs) confer resistance to beta-lactam antibiotics other than monbactams. It threatens public health because of its vast scope of action and quick spread. The study was undertaken to assess the occurrence of MBL in clinical isolates of Pseudomonas aeruginosa in the Enugu metropolis and to determine their resistance profile. Materials and Methods: The work was conducted from October 2020 to July 2021 in the microbiology laboratory of the University of Nigeria Teaching Hospital, Ituku-Ozalla. A total of 127 non-duplicate bacterial isolates recovered from clinical samples including wounds, urine, sputum, ear discharge, and catheter tip processed in the microbiology laboratory of four referral hospitals within the Enugu metropolis was used for the study. Isolates were identified and characterized using standard microbiology protocols. Antimicrobial susceptibility was done using the Kirby-Bauer disc diffusion method. Phenotypic detection of Metallo-beta-lactamase production was done using the Combined Disk diffusion Test (CDDT). Results: Of the 127 isolates, 68 (53.5%) were resistant to imipenem. Among these, 35 strains were positive for MBL production while 33 isolates were non-MBL producers. The highest percentage occurrence of MBL producers was recorded from catheter tips 33% followed by urine 30.6%. Both MBL producers and non-MBL producers displayed high resistance to most of the antibiotics used except Aztreonam. Conclusion: The overall occurrence of MBL among Pseudomonas aeruginosa in our study was found to be 27.6%. MBL-producing strains showed higher resistance than the non-MBL-producing strains. Aztreonam was the most potent antibiotic. The most effective approaches to combating this organism include early detection, stringent antibiotic regimens, and adherence to infection control measures.

Bacterial, fungal pathogens, and antimicrobial resistance patterns in ocular infections: Insights from a tertiary care hospital, North Karnataka

Background: Ocular infections, including conjunctivitis, keratitis, and endophthalmitis, significantly impact eye health, leading to morbidity, visual impairment, and blindness if not treated. Aims and Objectives: This study focuses on reviewing and analyzing the prevalence of bacterial and fungal pathogens in ocular infections and assessing their antimicrobial susceptibility patterns at Vijayanagar Institute of Medical Sciences, Ballari. Materials and Methods: A cross-sectional study was conducted by collecting ocular infection samples from January 01, 2022, to December 31, 2022. Samples, including corneal scrapings and conjunctival swabs, underwent initial procedures such as Gram staining and were inoculated on various agars. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disk diffusion method. Results: Out of 404 evaluated samples, corneal scrapings were predominant, with a significant incidence of fungal and bacterial growth. Aspergillus spp. and Pseudomonas spp. were the most common fungal and bacterial isolates, respectively. Antimicrobial susceptibility testing revealed that Gram-negative bacilli showed more susceptibility to gentamycin, ceftriaxone, and ciprofloxacin, whereas Gram-positive cocci were more susceptible to tetracycline and doxycycline. Conclusion: The study highlights the cornea as the most common source of ocular infections, with Aspergillus and Pseudomonas spp. being the predominant fungal and bacterial pathogens, respectively. Identifying the prevalent species in this geographical area aids in early diagnosis and treatment, thereby preventing morbidity and improving patient outcomes. The antimicrobial susceptibility pattern observed suggests effective options for treatment, emphasizing the need for ongoing surveillance to adapt to resistance patterns.