Disc Diffusion Method Research Articles

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

Tigecycline Resistant Pattern among Carbapenem Resistant Gram-negative Bacilli: Prospective Cross-sectional Study

Introduction: Tigecycline is a unique tetracycline class of semi-synthetic, last-line broad spectrum antibiotic against multi-drug-resistant bacteria. However, recently, resistance to this antibiotic is on the rise. Aims: This study was conducted to determine the prevalence of tigecycline resistance amongst carbapenem-resistant Gram-negative bacilli (GNB) isolated from clinical samples (pus and sputum) as well as to evaluate their antimicrobial susceptibility pattern. Study design: Prospective cross sectional Place and Duration of Study: Department of Microbiology at Sanjay Gandhi Post Graduate Institute of Medical Sciences Lucknow, between January 2023 and December 2023. Methodology: Identification of GNB grown on culture was done by conventional biochemical tests and later validated by MALDI-TOF MS. The antimicrobial sensitivity testing of isolates was done using the E-test, and disk diffusion method. Minimum inhibitory concentration determination was done by Broth micro-dilution (BMD) method. Results: Amongst 8326 pus and respiratory samples, GNBs were recovered from 63.15% (5258/8326). Of 5258 GNB isolates, 50.74% (2668) were carbapenem-resistant, while 7.85% (413) demonstrated resistance to both tigecycline and carbapenem. Common isolates in this group were Klebsiella pneumoniae (37.04%), Acinetobacter spp. (25.18%), Enterobacter spp. (14.28%) and Escherichia coli (12.59%). BMD results demonstrated highest activity of tigecycline against carbapenem-resistant E. coli, followed by Citrobacter and Enterobacter. It works against resistant strains of Acinetobacter baumannii and K. pneumoniae as well, but in higher concentrations. Conclusion: High tigecycline resistance (one of the last-resort drugs) among carbapenem resistant GNB isolates is a matter of clinical concern, leaving physicians with limited options for treatment of such infections. Proper adherence to the policies of antimicrobial stewardship programs can reduce the emergence of resistance.

Characterization of Clonal Groups of Antibiotic-Resistant Biofilm-Forming Staphylococcus aureus Strains Isolated from Patients with Urinary Tract Infections in Isfahan, Iran

Background: Over the past decades, the role of biofilm-forming Staphylococcus aureus strains in urinary tract infections (UTIs) has garnered significant attention. Objectives: This study aimed to determine the epidemiological characteristics and diversity of S. aureus strains isolated from patients with UTIs in Isfahan, Iran, in 2017, with regard to their antimicrobial resistance, biofilm formation, and phylogenetic profiles. Additionally, the study investigated potential relationships among these factors statistically to develop efficient control and treatment approaches. Methods: All patients with symptomatic UTIs who had positive urine cultures for S. aureus during the study period at the laboratory of a referral hospital in Isfahan were included. All isolates were identified using specific primers for the nucA gene. Their biofilm formation capacity was evaluated using a combination of the microtiter plate and Congo-red agar methods. Antibiotic susceptibility testing was performed using the disk diffusion method. The presence of genes involved in biofilm formation and resistance to cefoxitin, aminoglycosides, and fluoroquinolones was detected using polymerase chain reaction (PCR). Staphylococcal cassette chromosome mec (SCCmec) typing, agr typing, and phene plate (PhP) typing were employed to investigate the diversity of collected strains. Results: Results showed that 19%, 57%, and 24% of confirmed S. aureus strains were strong, intermediate, and non-biofilm formers, respectively. The highest rate of resistance was against nalidixic acid (77%), followed by streptomycin (73%). The icaD and icaA genes had the highest frequency among biofilm-producing strains. gyrA (44%) and grlA (35%) were the most frequent genes among fluoroquinolone-resistant strains, while aph(3′)-IIIa was the most prevalent aminoglycoside-modifying enzyme gene. The majority of bacterial strains harbored SCCmec type III and agr type I. PhP typing of strains revealed the presence of 8 common types (CTs) and 14 single types (STs), with CT2 being the dominant type. Conclusions: The present investigation revealed various biofilm production capacities, antimicrobial resistance profiles, and clonal lineages in S. aureus isolated from patients with UTIs. These findings provide further insights into the epidemiology and pathogenicity of S. aureus strains in Iran, thereby improving the quality of surveillance and therapeutic protocols.

Prevalence, serotype distribution, and antimicrobial susceptibility profile of Streptococcus pneumoniae in Sea Nomad children under 5 years of age in Wakatobi, Southeast Sulawesi, Indonesia: A cross-sectional study

ObjectiveIndonesia commenced the nationwide introduction of pneumococcal conjugate vaccine (PCV) in 2022. Pre-vaccine Streptococcus pneumoniae data from across the country could be critical to enable vaccine impact evaluation in the future. This study evaluates colonization prevalence, factors associated with colonization, serotype distribution, and the antimicrobial susceptibility profile of S. pneumoniae. MethodsChildren under 5 years of age were enrolled from Bajau tribe settlements in Wakatobi, southeast Sulawesi, Indonesia, from October 2018 to February 2019. Nasopharyngeal swab specimens were analysed by culture, and isolates were serotyped using sequential multiplex polymerase chain reaction. Antibiotic susceptibility was performed by the disk diffusion method. Multivariable logistic regression was performed for risk factor analysis. ResultsA total of 499 NP swab specimens were collected; 61.9% were colonized with S. pneumoniae and 48.9% of the isolates were of PCV13-vaccine type. The most common serotypes were 23F, 6B, 19F, and 6A at 13.2%, 9.8%, 8.9%, and 8.0%, respectively. Exposure to cigarette smoke in the household and runny nose were significant risk factors for colonization, with aORs of 1.6 (95% confidence interval: 1.1–2.3) and 2.1 (95% confidence interval: 1.4–3.3), respectively. ConclusionsThe findings of this study may contribute to baseline pre-vaccine data in Indonesia that would be critical for the impact evaluation of vaccines.

MES surfactant-based liquid soaps added with eco-enzyme and pandan wangi leaf extract (Pandanus amaryllifolius Roxb) on physical-chemistry properties, and antibacterial activity,"

The growing demand for liquid soap has spurred innovations in soap formulations, particularly using methyl ester sulfonate (MES) as a surfactant base combined with natural ingredients like eco-enzyme and fragrant pandan leaf extract. This study aimed to determine the optimal liquid soap formulation by evaluating physicochemical properties and antibacterial activity against Staphylococcus aureus. The research was conducted in two stages. First, liquid soap was produced at different temperatures (20°C, 50°C, and 100°C) to identify the optimal temperature based on maximum lipase activity. In the second stage, various formulations were prepared, incorporating eco-enzyme and fragrant pandan leaf extract at the identified optimal temperature. The six formulations tested were: F1 (MES-based soap), F2 (20% eco-enzyme), F3 (15% eco-enzyme and 5% fragrant pandan leaf extract), F4 (10% eco-enzyme and 10% fragrant pandan leaf extract), F5 (5% eco-enzyme and 15% fragrant pandan leaf extract), and F6 (20% fragrant pandan leaf extract). The formulations were assessed for lipase activity, pH, density, and viscosity. The most effective formulation was further tested for antibacterial activity using the disc diffusion method with six treatments, including MES-based soap and controls. Statistical analysis using One-Way ANOVA revealed that adding eco-enzyme and fragrant pandan leaf extract significantly affected the soap's properties. The optimal formulation, containing 5% eco-enzyme and 15% fragrant pandan leaf extract, exhibited a lipase activity of 15,778 U/mL, a pH of 5.02, a density of 1.06 g/mL, a viscosity of 3.59 cP, and an antibacterial zone of 37.22 mm, making it the best candidate for further development

Enteropathogenic and Multidrug-Resistant blaCTX-M-Carrying E. coli Isolates from Dogs and Cats.

Enteropathogenic Escherichia coli (EPEC) are pathogens associated with gastrointestinal illnesses. Dogs and cats can harbor EPEC, and antimicrobial resistance may impair necessary treatments. This study characterized E. coli strains from dogs and cats, focusing on phylogroup classification, virulence factors, and antimicrobial resistance profiles. Ninety-seven E. coli isolates from fecal samples of 31 dogs and 3 cats were obtained from a private diagnostic laboratory in Botucatu, Brazil, from March to October 2021. The antimicrobial susceptibility was assessed using the disk diffusion method. Polymerase chain reaction (PCR) was employed to screen for blaCTX-M and genes encoding virulence factors, as well as to classify the isolates into phylogroups. Twenty isolates were positive for intimin encoding gene eae and, consequently, these isolates were classified as EPEC (20.62%). Notably, 5.1% (5/97) of the isolates exhibited extended-spectrum β-lactamase (ESBL) production and 13.4% (13/97) were identified as multidrug-resistant bacteria. Phylogroups A and B2 were the most prevalent, comprising 29.9% (29/97) and 26.8% (26/97) of the bacterial isolates, respectively. This characterization highlights the prevalence of EPEC in domestic animals, emphasizing the potential risk they pose to public health and highlighting the urgency of responsible antimicrobial use in veterinary practices and the important role of laboratories in the surveillance of pathogenic multidrug-resistant bacteria.

Comparison of Beta-Lactamase Profiles and Epidemiology of Multi-Drug Resistant Acinetobacter baumannii Isolates in Southwest Turkey: 2011 vs. 2019 Study

Background: The most significant problem encountered with hospital infections caused by multi-drug resistant Acinetobacter baumannii isolates is the difficulty in treatment. Defining resistance mechanisms is important for the development of treatment strategies. Objectives: The aim of this study was to investigate the beta-lactamase genes and clonal relationship in multi-drug resistant A. baumannii isolates in Mugla, Turkey, as no data are currently available for this province. Methods: Total 96 multi-drug resistant A. baumannii isolates obtained from hospitalized patients, between 2011 - 2012 period (n = 61) and in year 2019 (n = 35) were investigated and compared for antibiotic susceptibilities, beta-lactamase enzyme encoding genes by polymerase chain reaction (PCR) method. Repetitive extragenic palindromic (REP) PCR was made for dendrogram analysis to illustrate hierarchical relationship between isolates. Results: Overall, 74.0% of the isolates were obtained from patients in intensive care units. All multi-drug resistant isolates were found resistant to ciprofloxacin, piperacillin, piperacillin-tazobactam, meropenem, and imipenem by the disk diffusion method. The minimum inhibitory concentration values indicated that all isolates were resistant to imipenem, while colistin resistance was determined as 21.9%. The ISAba-I insertion element was present in all isolates. BlaOXA-23-like was present in 96.9%, and blaOXA-24-like was detected in three (3.1%) isolates. blaNDM positivity was shown in 5.2% of isolates. The indistinguishable or closely related isolates ratio was detected as 29.5% for the 2011 - 2012 period and 80% for 2019. Conclusions: Our findings showed that antibiotic resistance rates were high in A. baumannii, particularly isolated from intensive care unit patients in Mugla province. The prevalence of beta-lactamase and metallo-beta-lactamase genes has been increasing year by year, with the blaOXA-23-like gene region being the most prevalent. Additionally, the co-existence of these genes among strains is also on the rise. These findings from two different periods may provide useful reference data for future studies.

Phytochemical fabrication of ZnO nanoparticles and their antibacterial and anti-biofilm activity

The synthesis of metal nanoparticles through bio-reduction is environmentally benign and devoid of impurities, which is very important for biological applications. This method aims to improve ZnO nanoparticle's antibacterial and anti-biofilm activity while reducing the amount of hazardous chemicals used in nanoparticle production. The assembly of zinc oxide nanoparticles (ZnO NPs) is presented via bio-reduction of an aqueous zinc nitrate solution using Echinochloacolona (E. colona) plant aqueous leaf extract comprising various phytochemical components such as phenols, flavonoids, proteins, and sugars. The synthesized nano ZnO NPs are characterized by UV–visible spectrophotometer (UV–vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (X-RD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elemental composition by energy-dispersive x-ray spectroscopy (EDX). The formation of biosynthesized ZnO nanoparticles was confirmed by the absorbance at 360–370 nm in the UV–vis spectrum. The average crystal size of the particles was found to be 15.8 nm, as calculated from XRD. SEM and TEM analysis of prepared ZnO NPs confirmed the spherical and hexagonal shaped nanoparticles. ZnO NPs showed antibacterial activity against Escherichia coli and Klebsiella pneumoniae with the largest zone of inhibition (ZOI) of 17 and 18 mm, respectively, from the disc diffusion method. Furthermore, ZnO NPs exhibited significant anti-biofilm activity in a dose-dependent manner against selected bacterial strains, thus suggesting that ZnO NPs can be deployed in the prevention of infectious diseases and also used in food preservation.

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.

Antimicrobial resistance characterization of Enterococcus faecium, Enterococcus faecalis and Enterococcus hirae isolated from marine coastal recreational waters in the State of São Paulo, Brazil.

Coastal water quality is facing increasing threats due to human activities. Their contamination by sewage discharges poses significant risks to the environment and public health. We aimed to investigate the presence of antibiotic-resistant Enterococcus in beach waters. Over a 10-month period, samples were collected from four beaches in the State of São Paulo (Brazil). Enterococcus isolates underwent matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) and molecular analysis for accurate genus and species identification. The antimicrobial susceptibility for 14 antibiotics was evaluated using the disc diffusion method followed by a multidrug-resistance (MDR) classification. PCR amplification method was used to detect antimicrobial resistance genes (ARGs). Our findings revealed the prevalence of Enterococcus faecalis, E. faecium and E. hirae. Out of 130 isolates, 118 were resistant to multiple antibiotics. The detection of resistance genes provided evidence of the potential transfer of antibiotic resistance within the environment. Our findings underscore the necessity for continuous research and surveillance to enhance understanding of the pathogenicity and antimicrobial resistance mechanisms of Enterococcus, which is crucial to implement effective measures to preserve the integrity of coastal ecosystems.

Assessment of the presence of multidrug-resistant Escherichiacoli, Salmonella and Staphylococcus in chicken meat, eggs and faeces in Mymensingh division of Bangladesh

The emergence of bacteria that is resistant to several drugs of clinical importance poses a threat to successful treatment, a phenomenon known as multidrug resistance that affects diverse classes of antibiotics. The purpose of this study was to evaluate the prevalence of multidrug-resistant Escherichiacoli, Salmonella spp. and Staphylococcusaureus in chicken egg, meat and faeces from four districts of Bangladesh. A total of 120 chicken samples were collected from different poultry farms. Conventional culture and molecular detection methods were used for identification of bacterial isolates from the collected samples followed by antibiotic susceptibility test through the disc diffusion method, finally antibiotic resistant genes were detected by PCR. E. coli, Salmonella spp. and Staphylococcusaureus were detected in meat, egg and faecal samples. Antimicrobial susceptibility results revealed isolates from faeces were 100 % resistant to amoxicillin, while all S.aureus and Salmonella sp. from faeces were resistant to doxycycline, tetracycline and erythromycin. Salmonella spp. isolates from eggs indicated 100 % resistance to erythromycin, amoxycillin, while E.coli were 100 % resistant to erythromycin. E.coli and S.aureus from meat were 100 % resistant to amoxicillin and erythromycin. However, Salmonella spp. from eggs were 100 % susceptible to doxycycline, gentamicin, levofloxacin and tetracycline. The mecA and aac(3)-IV genes were only found in S.aureus and E.coli, respectively. The Sul1,tetB, and aadA1 were highest in Salmonella spp. and S.aureus, while the sul1,tetA and blaSHV were higher in E.coli. Isolates from all samples were multidrug resistant. These findings indicate a high risk of transmission of resistance genes from microbial contamination to food of animal origin. The study emphasizes the need for effective biosecurity measures, responsible antibiotic use, and strict regulations in poultry production to prevent the spread of antibiotic resistance.

Synthesis of Silver Nanoparticles Using Haplophyllum robustum Bge. Extract: Antibacterial, Antifungal, and Scolicidal activity against Echinococcus granulosus Protoscolices

Background: Silver nanoparticles (AgNPs) biosynthesized via the deployment of plant extractives have garnered much attention, especially due to their antimicrobial properties. Herein, the green synthesis of silver nanoparticles has been accomplished using the aqueous extract of Haplophyllum robustum, which includes a study of its antibacterial, antifungal, and scolicidal activity. Methods: The preparative process was followed by characterization using UV-Vis spectroscopy, and the ensuing spherical AgNPs of average size 7-25 nm were identified by Dynamic Light Scattering (DLS), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The antibacterial, antifungal, and scolicidal activities of AgNPs were assessed by deploying disc diffusion and microdilution methods against four standard bacteria and four typical Candida species and liver hydatid cyst protoscoleces, where they exhibited good biological activity. Results: The results showed that the greener synthesis of silver nanoparticles using the aqueous extract of renewable and abundant H. robustum plant is a simple, inexpensive, and safer alternative that does not use any toxic or harmful substances. Conclusion: Thus, with minimal or no side effects, this approach to AgNPs bodes well for their appliances as antibacterial, antifungal, and scolicidal agents.

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.

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.

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<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

Isolation and characterisation of Stenotrophomonas maltophilia, a multidrug resistant opportunistic pathogen from cultured Rainbow trout (Oncorhynchus mykiss, walbaum, 1792) in India

The farming of Rainbow trout, an exotic fish has advanced on a huge scale in north western regions of India which provides the best suitable climate and topography for its culture. The advancement in farming is challenged by the infectious diseases. The isolation of Stenotrophomonas maltophilia, an opportunistic pathogen has been reported from the cultured channel catfish in china, and cultured African catfish in West Bengal, India. The present study reports isolation of Stenotrophomonas maltophilia from the kidney of Rainbow trout, Oncorhynchus mykiss along with its biochemical, 16 s rRNA sequencing and phylogenetic analysis. Antibiotic susceptibility of isolates to 10 antimicrobial drugs was investigated using Disc diffusion method. The isolates were found to be resistant to multiple drugs, characterised by resistance to all Beta-lactams (Methicillin and Ampicillin), Macrolides (Erythromycin, Azithromycin and Rifampicin), aminoglycosides (Streptomycin, Amikicin) except Gentamicin and susceptible to Tetracycline and Chloramphenicol antibiotics. The auto-aggregation capability of the isolates showed 55.02 ± 5.9 and 49.52 ± 7.6% auto-aggregation after 24 h of incubation, respectively. The isolates showed 32.77 ± 6.78 and 29.41 ± 7.71 % hydrophobicity after 2 h of extraction with xylene, respectively. The 16 s rRNA sequences of the were submitted to the GenBank database with the accession numbers OP647420 and PP077305.

Challenges Facing Two Outbreaks of Carbapenem-Resistant Acinetobacter baumannii: From Cefiderocol Susceptibility Testing to the Emergence of Cefiderocol-Resistant Mutants.

Carbapenem-resistant Acinetobacter baumannii (CRAB) infections are associated with poor outcomes depending on patient's conditions, clinical severity and type of infection, and treatment is challenging given the limited therapeutic options available. The aim of this study was to describe the clinical and microbiological characteristics of two outbreaks caused by CRAB in an intensive care unit (ICU). In addition, the mechanisms of resistance detected in these strains and the treatment chosen according to the available therapeutic options were analyzed. Overall, 28 patients were included. Ten patients (35.71%) had ventilator-associated pneumonia (VAP), ten (35.71%) had a bloodstream infection (BSI), and eight (28.57%) were only colonized. Recurrent infection occurred in 25% (5/20) of infected patients. Two different strains of A. baumannii were isolated from the index patient of the first outbreak. The first strain belonged to the ST85 and carried the blaNDM-1 carbapenemase gene, while the second belonged to the ST2 and carried blaOXA-23, and blaOXA-66 carbapenemase genes. The phylogenetic analysis revealed that the ST2 strain was the cause of the major outbreak, and mutations in the AmpC gene were related to progressive increasing minimum inhibitory concentration (MIC) and finally, cefiderocol-resistance in one strain. The CRAB isolates from the second outbreak were also identified as ST2. Cefiderocol-resistant strains tests identified by the disc diffusion method were involved in 24% (6/25) of nosocomial infections. Using broth microdilution (BMD) ComASP® only, 33.3% (2/6) of these strains were cefiderocol-resistant. All-cause ICU mortality was 21.4%. Conclusions: Cefiderocol is the first approved siderophore cephalosporin for the treatment of CRAB infections. Cefiderocol-resistant strains were related with blaNDM-1 carbapenemase and mutations in the AmpC gene. Cefiderocol-resistant strains or that cannot be properly interpreted by disk diffusion, should be retested using BMD for definitive categorization.

Antimicrobial Activity of Olive Leaf Extract to Oral Candida Isolates.

The aim of this study was to determine the antifungal activity of olive leaf extract (OLE) and the synergistic effect of standard antifungal therapy and OLE against clinical oral Candida species' isolates. The susceptibility of 60 clinical isolates of the Candida species (36 C. albicans, 16 C. krusei, 5 C. glabrata and 3 C. tropicalis) was tested with four concentrations of OLE (60 µg/µL, 120 µg/µL, 240 µg/µL and 333 µg/µL) and the synergistic effect of standard antifungal therapy and OLE (miconazole (MIC) + 333 µg/µL OLE and nystatin (NYS) + 333 µg/µL OLE). The antimicrobial activity was tested using the disk diffusion method. All concentrations (60 µg/µL, 120 µg/µL, 240 µg/µL and 333 µg/µL) of OLE showed a statistically significant effect on all Candida species compared to the control (DMSO) except for the lowest concentration (60 µg/µL) tested on C. glabrata. There was a dose-dependent effect of OLE on tested samples. Concentrations of 240 µg/µL and 333 µg/µL showed statistically significant higher antifungal activity compared to the lowest concentration of 60 µg/µL. No statistically significant synergistic effect of OLE and standard antifungal therapy was found compared with standard therapy alone. The results of this study present the significant antimicrobial effect of OLE against all tested Candida species except for the lowest concentration on C. glabrata. Increasing the concentration of OLE also increases its effect on Candida species. This indicates the possible potential effect of OLE in the treatment of Candida-related oral diseases.

Swordtail (Xiphophorous helleri) growth promoting activity and antibacterial property of pineapple (Ananas comosus) peel oil

The use of phytogenics that are low-cost and highly available has the potential to address some environmental, social, and economic issues in fish culture. The present study was conducted to evaluate the effects of the dietary application of pineapple (Ananas comosus) peel oil (PPO) on the growth performance of Swordtail (Xiphophorous helleri) and the antibacterial effect against pathogenic bacteria. PPO was incorporated in the diet of Swordtail (initial average weight ± SD of 0.12±0.07g and average length± SD of1.15±0.25 cm) to analyze the effect on growth performance. Two triplicate groups (each tank stocked with 15 fish) were fed with control and experimental diet for 10 weeks. The results showed significantly enhanced growth performance of fish fed with an experimental diet. The average weight gain (282.0±35.0%), relative growth rate (2.82±0.35), specific growth rate (1.92±0.12 %day-1), and condition factor (0.42±0.02%) were all higher, and feed conversion ratio (0.0219 ±0.040) is lower in fish fed the experimental diet. The carbohydrate content (60.05±0.050 %) in the control feed was higher (p≤0.05), whereas moisture (11.35±0.11 %) and ash (13.77±0.03%) contents were higher (p≤0.05) in experimental feed. The disc-diffusion method was used to test the antibacterial activity of the crude PPO against A. hydrophila and Pseudomonas spp. The inhibition zones were 2.37±0.13 51 cm and 2.06±0.08 cm, respectively. Conclusively, the present study recommends using PPO, which has a potential antibacterial effect against bacterial pathogens, as a potential feed additive to improve the growth performance of swordtail.

Solid waste dumpsite leachate and contiguous surface water contain multidrug-resistant ESBL-producing Escherichia coli carrying Extended Spectrum β-Lactamase (ESBL) genes

Dumpsites generate leachates containing bacteria that may carry antibiotic resistance genes, such as extended spectrum β-lactamase (ESBL). However, the contribution of dumpsite leachates in the environmental spread of ESBL genes has not been investigated in greater detail. This study aimed to quantify the impact of Ajakanga dumpsite leachate on the spread of ESBL genes through surface water. The susceptibility of Escherichia coli isolated from dumpsite leachate and the accompanying surface water to selected antibiotics was assessed by the standardized disc diffusion method. The isolates were evaluated for phenotypic ESBL production using the double disc synergy test (DDST). The detection of ESBL genes in the isolates was carried out using a primer-specific polymerase chain reaction (PCR). Escherichia coli isolates from leachate (n = 26/32) and surface water (n = 9/12) expressed ESBL phenotype. The ESBL-producing isolates showed the highest level of resistance to the 3rd generation cephalosporin antibiotics: cefotaxime (100%), cefpodoxime (97%), ceftazidime (97%), with low resistance observed to imipenem (6%) and azithromycin (3%). All the isolates were multidrug-resistant, showing resistance to three or more classes of antibiotics. All the ESBL-producing E. coli obtained carried blaCTX−M, 21/35 (60%) carried blaTEM while none of the isolates bore blaSHV. This study found that ESBL-producing Escherichia coli from dumpsite leachate and nearby surface water had identical resistance signatures indicating the relatedness of the isolates, and that dumpsite leachate could contribute to the transfer of ESBL-producing bacteria and their genes to receiving surface water. This study has necessitated the need for a review of the guidelines and operational procedures of dumpsites to forestall a potential public health challenge.