Antibiotic Resistance Profiles Research Articles

Insights into incompatible plasmids in multidrug-resistant Raoultella superbugs

The emergence of multidrug-resistant (MDR) Raoultella isolates is linked to the acquisition of antibiotic resistance genes (ARGs) with plasmids playing a pivotal role in this process. While plasmid-mediated transmission of ARGs in Raoultella has been extensively reported, limited attention has been given to genetically dissecting the modular structures of plasmids. This study aims to elucidate the genomic features of novel incompatible plasmids in MDR Raoultella by presenting 13 complete plasmid sequences from four isolates, along with an analysis of 16 related plasmids from GenBank. These 29 plasmids were classified into five distinct groups: IncFII single-replicon plasmids, dual-replicon plasmids containing the IncFII replicon, IncHI plasmids, IncR plasmids, and IncX8 plasmids. A new incompatible group, IncFIIp23141−CTXM, was identified, alongside five newly designated Inc groups based on previously determined sequences, namely IncFIIpKPC2_EC14653, IncFIIpCP020359, IncFIIpCP024509, IncFIIpKOX−137, and IncFIIpKDO1. Furthermore, this research marks the first report of four Inc groups of plasmids within Raoultella, namely IncFIIp23141−CTXM plasmid, IncFIIpKPC2_EC14653 plasmid, IncX8 plasmid, and IncFIIpCP020359: IncFIB-7.1 dual-replicon plasmid. Moreover, novel mobile genetic elements, including two unit transposons (Tn6806 and Tn6891), one IS-based transposition unit (Tn6561), and four insertion sequences (ISRor6, ISRor7, ISRor8, and ISRor9) were discovered. Notably, this is the first report of mcr-9 in clinical Raoultella strains. At least 49 ARGs conferring resistance against 11 different categories of antimicrobials were identified on these 13 plasmids. Overall, this research deepens the understanding of incompatible plasmids in Raoultella, serving as a reference for exploring antibiotic resistance profiles and plasmid diversity in MDR Raoultella.

P-1296. Community-acquired methicillin-resistant Staphylococcus aureus infections: 1 year of surveillance in 6 pediatric centers

Abstract Background Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections is emerging in the world and can have a serious evolution. The objective of this study were to study the hospitalization rate, the clinical-epidemiological and bacteriological pattern and the case fatality risk factors of CA-MRSA infection. Methods Cross-sectional observational epidemiological study, with prospective data capture. All patients ≤ 15 years of age with community-acquired Staphylococcus aureus (CA-SA) infection hospitalized in 6 pediatric sentinel units, between January and December 2023, were included. The rate of CA-MRSA cases per 10,000 hospital discharges was calculated. with 95 % confidence interval (95 % CI). Results Of a total of 201 patients with CA-SA infection, 131 (65.2 %) were CA-MRSA. The global hospitalization rate for CA-MRSA cases was 27.8 (23.3-32.9), with a higher rate in < 2 years 37,7 (27,9-49,8). Of the 131 cases: 56.5 % were male, median age 48.8 months (IQR 16.4-90.4), ≥ 2 years 64.9%, complete vaccination card 77.0 %, low socioeconomic level 54.2 %, overcrowding 15.3 %, underlying disease 29.0 %, passive smoking 24.4 %. The clinical presentations were (n; %): skin and soft tissue infection (SSTI 101; 77.1 %), arthritis (17; 13.0 %), osteomyelitis (12; 9.2 %), pneumonia (16; 12.2 %; 14 with pleural effusion and 3 necrotizing), sepsis (11; 8.4 %), bacteremia (4; 3.1 %), meningitis (1; 0.8 %). Conventional microbiological diagnosis was performed in 130 cases and molecular diagnosis in one. 4 cases had coinfection with group A beta hemolytic Streptococcus. Antibiotic resistance was for erythromycin 43.1 %, clindamycin 26.0 %, gentamicin 19.9 %, TMP-SMX 1.5 %. All strains were susceptible to vancomycin. Fatality rate: 1.5 % (2/131). No deceased case had an underlying disease. 18.2 % (2/11) of sepsis cases died (2-tailed Fisher exact p 0.006), however, there was no significant association in the multivariate analysis. Conclusion The high burden of CA-MRSA infection, the most common clinical form of SSTI, and the high profile of antibiotic resistance, highlight the importance of continuous clinical surveillance and alert for these infections. Disclosures All Authors: No reported disclosures

P-647. Comparative efficacy of antibiotic regimens against Ureaplasma species with varying antibiotic resistance profiles in a mouse model of lung infection

Abstract Background Lung transplant recipients (LTRs) can experience hyperammonemia syndrome (HS) correlated with lung infection by ammonia-producing Ureaplasma species. HS in LTRs can be managed by Ureaplasma-directed antibiotic therapy; however, Ureaplasma species lack a cell wall, limiting treatment options. Precise guidelines for Ureaplasma-directed antibiotic therapy in LTRs is lacking, and antibiotic resistance may complicate treatment. Here, levofloxacin (LEV), azithromycin (AZM), and doxycycline (DOX) were tested against isolates of U. urealyticum and U. parvum with varying antibiotic resistance profiles, and efficacies compared.Fig 1.Antibiotic prophylaxis of murine infection by antibiotic resistant Ureaplasma isolates. Mice were prophylaxed with levofloxacin (LEV; 100 mg/kg SQ), azithromycin (AZM; 100 mg/kg PO), or doxycycline (DOX; 100 mg/kg IP) 12 hours prior to infection with isolates of Ureaplasma parvum or Ureaplasma urealyticum resistant to one or none of the antibiotics. 18 hours after infection, mice were sacrificed and lungs harvested, with resulting Ureaplasma loads quantified (color changing units: CCU). Control animals (CTRL) were given no antibiotics. Significance between groups was determined via Kruskal-Wallis tests with Dunn’s multiple comparison tests. * p ≤0.05, **p ≤0.01, ***p ≤0.001. Methods Mice were immunosuppressed using a combination of tacrolimus (1.2 mg/kg daily), mycophenolate mofetil (40 mg/kg daily), and methylprednisolone (20 mg/kg weekly) to mimic immunosuppression given to LTRs. Prophylactic antibiotics were given 12 hours prior to infection, including either LEV (100 mg/kg subcutaneously), AZM (100 mg/kg orally), or DOX (100 mg/kg intraperitoneally). Mice were then infected with Ureaplasma isolates resistant to one or none of the antibiotics, including U. parvum IDRL-10774 (fully susceptible), U parvum IDRL-10774R (IDLR-10774 with evolved AZM resistance; serial passage in sub-MIC AZM), U. parvum IDRL-11160 (LEV resistant), and U. urealyticum ATCC-33175 (DOX resistant). Mice were euthanized 18 hours post-infection, and lung bacterial loads (color changing units; CCU/gram) quantified. Results The effect of various antibiotic treatments against mouse lung infections with the four Ureaplasma isolates is displayed in Fig 1. Infection with IDRL-10774 (fully susceptible) and IDRL-11160 (LEV resistant) was only prevented by doxycycline (p=0.09 and p=0.01, respectively). For IDRL-10774, insignificant mean reductions (possibly due to a high standard deviation in the controls) were observed for both LEV (-106.9 CCU/g) and AZM (-105.25 CCU/g). IDRL-10774R (evolved AZM resistance) showed a complete loss of susceptibility to AZM compared to unevolved IDRL-10774. ATCC-33175 (DOX resistant) was not reduced by any antibiotics tested. Conclusion DOX was the most effective antibiotic tested, preventing lung infection by all isolates, except a DOX resistant isolate. Disclosures Robin Patel, MD, a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, a: See above|MicuRx Pharmaceuticals and BIOFIRE: Grant/Research Support|PhAST, Day Zero Diagnostics, Abbott Laboratories, Sysmex, DEEPULL DIAGNOSTICS, S.L., Netflix, Oxford Nanopore Technologies and CARB-X: Advisor/Consultant|Up-to-Date and the Infectious Diseases Board Review Course.: Honoraria

Identification and antibiotics resistance profile of gram-negative bacteria isolated from sediment Anil river in Maranhão, Brazil

The Manguezal ecosystem suffers impacts from human anthropic actions, which can cause transformations in the microbiota and selection of antibiotic-resistant variants. Thus, this study aimed to isolate and identify gram-negative bacteria to characterize the resistance genes to b-lactam antibiotics from sediment samples from the Anil River – MA (Manguezais area). The bacterial isolate was obtained from sediment samples plated on Macconkey Agar supplemented with antibiotics ceftazidime and meropenem. MALDI-QTOF identified the isolated bacterial species. The bacterial isolates were subjected to the Kirby-Bauer method to evaluate the antibiotic susceptibility profile. The PCR technique detected the genetic determinants. This study identified three and two bacteria; 20 isolates were classified as Ochrobactrum intermedium, 09 Ochrobactrum tritici, 02 Stenotrophomonas maltophilia, and 01 Klebsiella pneumoniae. In antibiotic susceptibility tests, it was observed that 100% (n=32) of the isolates were resistant to cefepime, 96.8% (n=31) to ofloxacin and ceftriaxone, and 90.6% (n=29) to imipenem. The molecular profile showed that 50% (n=16) presented the blaGES gene. In addition, genes belonging to the blaOXA profile were identified in 21 bacteria isolates from the genus Ochrobactrum, with the blaOXA1 gene being the most prevalent among the isolates, identified in 11 bacterial lines. This study confirms that environments such as mangroves, which act as reservoirs of bacteria resistant to multiple antimicrobial drugs for clinical use, become a risk to human health.

From Metagenomes to Functional Expression of Resistance: floR Gene Diversity in Bacteria from Salmon Farms

Background. The increase in antibiotic resistance in human-impacted environments, such as coastal waters with aquaculture activity, is related to the widespread use of antibiotics, even at sub-lethal concentrations. In Chile, the world’s second largest producer of salmon, aquaculture is considered the main source of antibiotics in coastal waters. In this work, we aimed to characterize the genetic and phenotypic profiles of antibiotic resistance in bacterial communities from salmon farms. Methods. Bacterial metagenomes from an intensive aquaculture zone in southern Chile were sequenced, and the composition, abundance and sequence of antibiotic resistance genes (ARGs) were analyzed using assembled and raw read data. Total DNA from bacterial communities was used as a template to recover floR gene variants, which were tested by heterologous expression and functional characterization of phenicol resistance. Results. Prediction of ARGs in salmon farm metagenomes using more permissive parameters yielded significantly more results than the default Resistance Gene Identifier (RGI) software. ARGs grouped into drug classes showed similar abundance profiles to global ocean bacteria. The floR gene was the most abundant phenicol-resistance gene with the lowest gene counts, showing a conserved sequence although with variations from the reference floR. These differences were recovered by RGI prediction and, in greater depth, by mapping reads to the floR sequence using SNP base-calling. These variants were analyzed by heterologous expression, revealing the co-existence of high- and low-resistance sequences in the environmental bacteria. Conclusions. This study highlights the importance of combining metagenomic and phenotypic approaches to study the genetic variability in and evolution of antibiotic-resistant bacteria associated with salmon farms.

Antimicrobial Resistance, Virulence Gene Profiling, and Spa Typing of Staphylococcus aureus Isolated from Retail Chicken Meat in Alabama, USA

Antibiotic-resistant Staphylococcus aureus (S. aureus) in retail meat poses a public health threat requiring continuous surveillance. This study investigated the frequency of isolation, toxin genes, and antibiotic resistance profile of S. aureus recovered from retail poultry meat samples and presented results beneficial to public health interventions. Of 200 samples collected, 16% (32/200) tested positive for S. aureus, and these were recovered from thigh 37.5% (12/32), wing 34.4% (11/32), gizzard (15.6% (5/32), and liver 12.5% (4/32) samples. Findings of spa typing analysis revealed that 68.8% (22/32), 18.8% (6/32), 9.4% (3/32), and 3.0% (1/32) of the isolates belonged to the spa types t267, t160, t548, and t008, respectively. For antibiotic susceptibility testing, 12.5% (4/32) of the isolates were resistant to only penicillin, but one isolate (1/32; 3%) showed resistance to the antibiotics penicillin, erythromycin, ampicillin, and oxacillin. PCR analysis revealed that 9.4% (3/32) of the isolates carried the mecA gene associated with methicillin-resistant Staphylococcus aureus (MRSA) isolates. One MRSA isolate was identified as a t008 spa type, and harbored a 26,974 bp-sized plasmid, which was the source of its resistance to penicillin, ampicillin, erythromycin, and oxacillin. The staphylococcal enterotoxin (SE) genes seg, sei, sek, seb, selm, and seln were also identified among the isolates, and mostly the antimicrobial and enterotoxin genes were carried on plasmids of the isolates. This study raises awareness on the continuous circulation of pathogenic microbes like S. aureus in retail poultry meat.

Genomic and Drug Resistance Profile of Bovine Multidrug-Resistant Escherichia coli Isolated in Kazakhstan.

While studying the prevalence and profile of antibiotic resistance among E. coli isolated from the feces of calves with signs of colibacillosis, a strain with a wide spectrum of drug resistance was isolated. Whole-genome sequencing, followed by bioinformatic processing and the annotation of genes of this strain, showed that the genome has a total length of 4,803,482 bp and contains 4986 genes, including 122 RNA genes. A total of 31% of the genes are functionally significant and represent 26 functional groups. Additionally, 55 antibiotic resistance genes were revealed. A phenotypic drug-resistance study was performed according to CASFM and CLSI guidelines, which showed that the investigated strain was resistant to eight antibacterial drugs of different classes, including colistin. This is the first report on the AMR profile of an E. coli isolate obtained from a sick calf with evidence of escherichiosis in Kazakhstan. The provided information on the genome will be valuable in studying the evolution and development of antibiotic-resistant forms of E. coli and increase our knowledge of pathogenicity. It may also be a source for future comparative studies of the virulence and drug resistance of E. coli isolates.

Genetic profile of antibiotic resistance of enterobacteria strains isolated from obstetrics, gynecology and pediatric patients

Background. Antibiotic resistance of microorganisms is a significant problem for public health in countries around the world. Studying the structure and prevalence of genetic determinants of antibiotic resistance is a current research area that makes it possible to determine the mechanisms of resistance to antibacterial drugs.Purpose of the study. To study the genetic profile of antibiotic resistance of Enterobacteriaceae strains isolated from obstetrics, gynecology and pediatric patients.Materials and methods. The genetic profile of antibiotic resistance was determined in ESBL-producing strains of Enterobacteriaceae isolated from samples of biological material obtained from 43 women and 24 children hospitalized in the departments of the Federal State Budgetary Institution “Research Institute of OMM” of the Russian Ministry of Health in 2024. The DNA of bacterial cells of ESBL-producing isolates was isolated from a daily culture of microorganisms using the PROBA-NK kit. Detection of genes blatem, blactx-M-1, blashv; blaoxa-40-like, blaoxa-48-like, blaоxa-23-like, blaoxa-51-like, blaimp, blaKPS, blaNDM, were carried out using the BakResist GLA kit on a DT-48 detection amplifier (DNA technology, Russia ).Results. In representatives of the Enterobacteriaceae family isolated from children, the blactx-M-1+blashv genovariant was identified in 29.2% of cases and was found only in Klebsiella pneumoniae. Blatem+blactx-M-1 was detected in 20.8%, and blactx-M-1+blashv+blatem — in 12%. Among representatives of the Enterobacteriaceae family isolated from women, the blactx-M-1 genovariant was found in 37.2% of cases and was detected only in Escherichia coli. And the options blactx-M-1+blatem and blactx-M-1+blashv — in 16.3%. In 2024, for the first time in 7 years of our research to identify the genetic determinants of antibiotic resistance, a multidrug-resistant Escherichia coli strain with the blaNDM gene was identified. Also noteworthy is the identification of K. pneumoniae with the genetic profile of antibiotic resistance blatem, blactx-M-1, blashv, blaoxa-48-like, blaNDM.Conclusion. The genetic profile of antibiotic resistance of Enterobacteriaceae strains isolated from patients in obstetrics, gynecology and pediatric departments is represented by 8 genovariants, in which the dominant gene providing resistance to beta-lactam antibiotics among Enterobacteriaceae in 2024, as in 2021, 2022, blaCTX-M-1 remains, which is found both as a monovariant and in association with blatem and blashv.

Virulence profile of carbapenem-resistant Klebsiella pneumoniae strains by an in vivo model of Galleria mellonella.

Klebsiella pneumoniae is a significant healthcare-associated pathogen, notable for its diverse virulence and antibiotic resistance profiles. This study aimed to characterize the genotypic and phenotypic diversity of K. pneumoniae isolates and evaluate their virulence using the Galleria mellonella model. Biomass production, metabolic activity, capsule formation, and siderophore production were assessed in 27 K. pneumoniae isolates from hospital-associated infections. Lethality curves were generated using the G. mellonella model, with survival monitored hourly from 16 to 48 hours. The most common sequence types (ST) identified were the high-risk clones ST307 (N = 10), ST512 (N = 8), ST101 (N = 7), and ST661 (N = 2). These STs were associated with distinct K-locus, including KL102, KL107, KL17, and KL39. Most isolates belonged to the O2afg locus (N = 18), with the K. pneumoniae carbapenemase genotype detected in 96.3% of strains. None of the isolates were classified as hypervirulent. Phenotypically, ST661 exhibited the highest biomass production despite showing similar metabolic activity to other STs. A positive correlation was observed between biomass and siderophore production, while capsule production was inversely correlated with biomass. In the G. mellonella model, ST661 demonstrated the highest virulence, resulting in 100% mortality by 48 hours, compared to survival rates of 21.4% for ST101, 38.0% for ST307, and 31.2% for ST512. These findings underscore the pathogenic potential of ST661 isolates with enhanced biofilm production. The G. mellonella model may serve as an effective in vivo system for evaluating the virulence of emerging K. pneumoniae lineages.IMPORTANCEWe demonstrate that the Galleria mellonella model is a useful tool to analyze the virulence of carbapenem-resistant Klebsiella pneumoniae strains. Our findings highlight the pathogenicity of carbapenem-resistant K pneumoniae isolates, particularly the role of the ST661 that, despite being a rare lineage, harbors the blaVIM gene and is associated with high biofilm production and the highest mortality rates.

Determination of Staphylococcus aureus isolation, identification and antibiotic susceptibility in raw milk

Staphylococcus aureus in raw milk poses a potential risk to public health due to its toxin-producing strains and high levels of antibiotic resistance. In this study, the presence of S. aureus in raw milk and the antibiotic resistance profiles of the isolated strains were examined. A total of 100 raw milk samples were analyzed, and S. aureus contamination was detected in 47 samples at various levels. The contamination levels ranged from 2.00 to 4.99 log cfu/ml and 45.9% of the contaminated samples were found to be in 3-4 log cfu/ml range. The minimum inhibitory concentration values for the antibiotics cefoxitin, methicillin, tetracycline, tylosin, florphenicol, neomycin, ciprofloxacin, lincomycin, and polymyxin B were determined using the broth microdilution method to examine the antibiotic resistance profiles of the isolated strains. It was determined that 13 (27.6%) of the S. aureus isolates were resistant to all the tested antibiotic groups. Additionally, all isolates were resistant to cefoxitin, methicillin, tylosin, and lincomycin, followed by resistance rates of 95.8% to florphenicol, 89.4% to neomycin, and 87.3% to polymyxin B. Furthermore, all isolates were observed to be multidrug-resistant (MDR). This study indicates that the contamination of raw milk with S. aureus and the antibiotic resistance profile pose a significant public health risk. The fact that all isolates were MDR limits treatment options and complicates infection control. These findings show that the need for stricter hygiene practices in milk production processes and careful management of antibiotic use.

Antibiotic Susceptibility Patterns in Gram-Positive and Gram-Negative Isolates from Post-Operative Wound Infections

Background: Post-operative wound infections (POWIs) are a leading cause of morbidity and increase in healthcare costs, especially in low resource settings. The rising prevalence of antibiotic resistance among pathogens also increases the complexity of treatment strategies, highlighting the importance of local surveillance of microbiological and resistance patterns. This study aims to find out the antibiotic susceptibility patterns of gram positive and gram negative isolates from the post-operative wound infections from women undergoing obstetric and gynecological surgeries. Methods: A cross-sectional study was conducted at Department of Obstetrics and Gynecology, Dhaka Medical College Hospital, Dhaka from October 2019 to September 2021. A total of 200 women with post-operative wound infections were purposively selected. Among them, 134 had culture-positive findings. Bacteriological analysis and antibiotic susceptibility testing were performed on isolates following standard microbiological methods. Results: Among the 134 culture-positive cases, 33.6% of isolates were gram-positive, with Staphylococcus aureus being predominant. Gram-negative bacteria accounted for 66.4% of isolates, with E. coli and Pseudomonas aeruginosa equally prevalent (20.9%). Gram-positive isolates showed high sensitivity to piperacillin-tazobactam (91.1%) and sulbactam (53.3%) but were resistant to ceftriaxone (48.9%) and cefixime (51.1%). Gram-negative bacteria exhibited sensitivity to amikacin and meropenem but demonstrated widespread resistance to ceftriaxone and doxycycline. Conclusion: This study describes the diverse microbiological profile and high prevalence of antibiotic resistance in POWIs. Novel antibiotic therapy and strict infection control measures are essential to curb the burden of these infections.

Clinical and molecular analysis of ESBL, carbapenemase, and colistin-resistant bacteria in UTI patients.

Uropathogens, particularly bacteria, can infect any part of the urinary tract and cause bacteriuria. Our study aimed to examine the antibiotic-resistant profile, associated risk factors, and phenotypic and genotypic features of ESBL, carbapenemase, and mcr resistance genes in multidrug-resistant bacteria. Samples were inoculated on culture media, identified using standard biochemical tests, and species confirmation was performed via 16S rRNA gene amplification. Furthermore, antibiotic susceptibilities were evaluated using the Kirby-Bauer disc diffusion method. The phenotypically confirmed resistant strains were further inspected for ESBL, carbapenemases, and mcr variants using PCR. Merely 57.24% (83/145) of the samples exhibited growth. Of these, 39.70% (33/83) were identified as Klebsiella pneumoniae, 27.70% (23/83) as Escherichia coli, 10.80% (9/83) as Pseudomonas aeruginosa, 9.60% (8/83) as Staphylococcus aureus, 7.20% (6/83) as Proteus mirabilis, and 4.80% (4/83) as Staphylococcus saprophyticus. Overall, 22.54% (16/71) of the gram-negative strains were confirmed molecularly to have resistant genes. The ESBL - producers accounted for 21.74% (5/23) of E. coli, 21.21% (7/33) of K. pneumoniae, and 22.22% (2/9) of P. aeruginosa. Likewise, carbapenemase-harboring strains included 6.06% (2/33) of K. pneumoniae, 4.35% (1/23) of E. coli, and 11.11% (1/9) of P. aeruginosa. Notably, 3.03% (1/33) of K. pneumoniae, 8.70% (2/23) of E. coli, and 11.11% (1/9) of P. aeruginosa strains tested positive for the mcr-1 gene. None of the Proteus strains showed any resistant genes. The most common variants were blaSHV-11 (non-ESBL) and blaCTX-M-15 (ESBL) accounted for 28.57% (4/14) each, blaTEM-116 accounted for 14.29% (2/14), blaSHV-1, blaSHV-75, blaTEM-1 and blaOXA-1 accounted for 7.14% (1/14) each of the ESBL. Similarly, the carbapenemase variants included blaOXA-48, blaNDM-1, blaVIM-1, and blaKPC-2, each accounting for 25.0% (1/4), while 37.50% (6/16) of the strains exhibited co-existence of different gene variants. Based on our findings, it can be concluded that females, especially those in middle age, were more infected. These pathogens exhibited a wide range of ESBL, carbapenemase, and mcr-1 variants. Imipenem was suggested as the preferred medication.

Microbial Colonization and Antibiotic Resistance Profiles in Chronic Wounds: A Comparative Study of Hidradenitis Suppurativa and Venous Ulcers.

Background/Objectives: Chronic wounds, including hidradenitis suppurativa (HS) and venous ulcers (VU), are commonly associated with complex microbial communities that may influence wound healing and treatment outcomes. Understanding microbial diversity and antibiotic resistance patterns is essential in order to optimize therapeutic strategies. This study aimed to investigate the microbial populations and antibiotic resistance profiles in HS and VU patients, comparing the prevalence of common pathogens and their antimicrobial resistance profiles. Methods: We conducted a cross-sectional analysis that included a total of 112 individuals (24 with the diagnosis of hidradenitis suppurativa and 88 diagnosed with venous ulcer). Wound swabs were cultured to identify bacterial species, and antibiotic resistance was assessed using a standard panel of antibiotics. Prevalence rates of key pathogens, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis, were compared between the two groups. Resistance patterns were analyzed using statistical methods to identify significant differences. Results: Staphylococcus aureus was the most common pathogen in both groups (45.8% in HS; 38.6% in VU), with a notable prevalence of methicillin-resistant S. aureus (MRSA). Pseudomonas aeruginosa was exclusively identified in VU patients (27.3%), while beta-hemolytic Streptococcus and Corynebacterium amycolatum were identified in HS cases only. Antibiotic resistance was moderate, notably in S. aureus and Proteus mirabilis, while one case of multidrug-resistant Pseudomonas aeruginosa was identified. Conclusions: This study highlights the distinctive microbial profiles and antibiotic resistance patterns in HS and VU chronic wounds. The predominance of S. aureus in both groups underscores the need for targeted therapies, while the absence of P. aeruginosa in HS wounds and the higher prevalence of other species emphasizes wound-specific microbial variations. These findings underscore the importance of personalized treatment strategies and continuous surveillance of antimicrobial resistance.

Molecular Detection and Characterization of Virulence Genes in Escherichia coli Isolated from Drinking Water and Raw Food Sources

Poor hygeine resluts in elevated levels of bacterial contamination in drinking water and raw food. Escherichia coli (E. coli) is one good indicator that shows the level of contamination in community water supply. E. coli horbour pathogenic and antibiotic resistance genes that can results in morbity. The aims of the study is to assess pathogenicnity and antibiotic resistance prevailing in water and food samples collected from Kohat. Method:Twenty samples were collected and subjected to various tests, including biochemical assays and polymerase chain reaction (PCR) to identify E. coli. Antibiogram assays were performed using Kirby disc diffusion method. PCR was employed to identify virulence genes (Stx-1 and Stx-2). Results: 70% of samples were found to have bacteria in them, and the most common were E. coli and other Enterobacteriaceae. Additional testing of E. coli-positive samples confirmed positive TSI results but negative citrate and urease tests. Antibiotic susceptibility testing revealed that most of samples were completely resistant to penicillin, ampicillin, ceftazidime, and cefixime, while some samples showed suseptibility to amoxicillin plus clavulanic acid, cefoxitin, cefepime, cefoperazone + sulbactum, levofloxacin, ceftriaxone, ciprofloxacin , clarithromycin, azithromycin and doxycycline as per CLSI standards. Three of the isolates were subjected to PCR for the detection STX1 and STX2 genes that confirmed the presence of the Stx2 gene in the two E. coli isolates, while Stx-1 was absent. Sequence analysis of Stx-2 gene showed >98% identity with GenBank sequences. Conclusions: In conclusion, this study employed a comprehensive approach to identify E. coli as a harmful pathogen in drinking water and raw food. The utilization of phylogenetic analysis, and virulence factor detection, along with antibiotic resistance profiling, enhances our understanding of E. coli contamination in resource-limited settings, highlighting the urgent need for improved wastewater management and hygiene practices.

Antibiotic Susceptibility Pattern of Bacterial Isolates from Infected Diabetic Foot Ulcer in Patients of Type 2 Diabetes Mellitus Presenting at Hayatabad Medical Complex Peshawar

Objectives: This study aimed to determine the antibiotic resistance profiles of bacterial isolates obtained from diabetic foot ulcers (DFUs) in type 2 diabetes patients at Hayatabad Medical Complex, Peshawar, by identifying the most prevalent bacterial species and their corresponding resistance patterns. Materials and Methods: This cross-sectional study was conducted over six months from March to September 2024, involving 120 clinically diagnosed patients with infected diabetic foot ulcers. Bacterial isolates were obtained from wound swabs and identified using standard cultural and biochemical tests. Antibiotic susceptibility was determined through the disc diffusion method. Results: The results indicated that 93.3% of wound swabs showed positive bacterial growth, predominantly gram-negative bacteria, with Escherichia coli (28%) and Klebsiella pneumoniae (22%) being the most prevalent isolates. Polymicrobial infections were found in 18% of samples. Resistance rates were notably high for ampicillin (72%) and ciprofloxacin (55%), while carbapenems and piperacillin-tazobactam demonstrated higher sensitivity. Among gram-positive isolates, methicillin-resistant Staphylococcus aureus (MRSA) was detected in 60% of cases. Conclusion: The research underscores the significant prevalence of multidrug-resistant (MDR) bacteria in diabetic foot ulcers, emphasizing the critical need for innovative approaches to antibiotic treatment and robust infection control strategies.

Study of Antibiotic Resistance in the Fish Gut and Antibacterial Potential of Lactic acid bacteria against the isolated Multiple Drug-resistant bacteria.

The One Health approach integrates human, animal, and environmental health to address emerging diseases. Antibiotic resistance spread among microorganisms has been a concern in all ecosystems including aquatic environments. This resistance is spreading horizontally in ways that are both hidden and unfathomable. The search for alternatives is the most important need for combating the spread of antibiotic resistance. This work aims to study the spread of antibiotic resistance through horizontal transmission via plasmids and the ability of bacteria to form biofilms. In this study, a total of 31 isolates were obtained from different fishes. Cultural, microscopic, and biochemical tests were performed to identify them. The antibiotic sensitivity was performed using the disc diffusion method with Oxytetracycline, Linezolid, Vancomycin, Imipenem, Cefoxitin, Ampicillin, and Amoxicillin. Plasmid extraction and biofilm-producing capacity of the resistant isolates were studied. 67 % of isolates were found to be gram-negative and 23 % gram-positive. Antibiotic resistance profiling showed a higher percentage of resistance in gram-negative organisms with maximum resistance to Oxytetracycline. Plasmids were found in 43% of the gram-negative isolates and out of these 83% were able to form biofilms. To screen for alternatives to antibiotics, cell-free extracts of Lactic acid bacteria were tested by the agar diffusion method, and a zone of inhibition was noted. This study highlights the challenging trend of antibiotic resistance spread in aquatic ecosystems and the need for antibiotic substitutes.

Profile and resistance pattern of Stenotrophomonas maltophilia in Dr. Soetomo General Academic Hospital During 2020-2022 Period

Introduction: Stenotrophomonas maltophilia is a challenging respiratory tract pathogen with increasing number of cases. S. maltophilia also shows a high resistance towards various antibiotics. The aim for this study is to know the antibiotic resistance pattern and profile of patient infected with S. maltophilia in order to find out effective antibiotic therapy in treating future cases. Methods: This cross-sectional study uses descriptive analytic method using medical record data of 36 patients infected with S. maltophilia in Dr. Soetomo General Academic Hospital during 2020-2022 period. The measured variables included antibiotic resistance pattern, age, sex, clinical diagnosis, comorbidity, signs and symptoms, medical device usage, total leukocyte count, and mortality rate. Result: S. maltophilia shows highest sensitivity index towards Trimetophrim-sulfomethoxazole (56%). Cases of S. maltophilia is most often found in 0-17 years age group (53%) and male (63%). It may cause infection whether alone or alongside other bacteria. The most common clinical diagnosis that occurs in S. maltophilia infections is pneumonia (81%). Dyspnea is the most occurred symptoms. Hypertension is a common comorbidity. IV infusion is the most used medical device. Might cause infection alongside other bacteria. Leukocytosis is often present. Mortality rate among subjects is 50%. Conclusion: Trimetophrim-sulfomethoxazole is the best treatment for S. maltophilia infections. Cases most often occurs in age 0-17 years, male, diagnosed with pneumonia, and has hypertension as comorbidity. In the future, antibiotics must be used wisely to prevent bacterial resistance and regular changing of medical device is encouraged to prevent nosocomial infections.

Gut Microbial Composition and Antibiotic Resistance Profiles in Dairy Calves with Diarrhea.

Calf diarrhea is a prevalent and significant health issue in dairy farming, severely impacting feed intake, weight gain, and survival rates in young calves. This study aimed to investigate the microbial composition and antibiotic resistance profiles of diarrheic calves to provide insights into the epidemiology and management of the condition. The prevalence of diarrhea in 1685 calves was analyzed. Rectal fecal samples were collected from five healthy and five diarrheic Holstein calves on a large dairy farm in Shaanxi Province, China. High-throughput 16S-rRNA sequencing and PCR were utilized for microbial and resistance gene analysis. In 2023, the overall diarrhea rate among 1685 calves was 9.08%, with a significantly higher diarrhea rate during the suckling period (8.13%) compared to the post-weaning period (0.95%) (p < 0.001). No differences in species diversity and richness were detected among the different groups. However, LEfSe analysis identified six genera (Eubacterium, Eubacteriaceae, Prevotella, Comamonadaceae, Comamonas, and Firmicutes) significantly enriched in diarrheic calves compared to healthy ones (LDA scores > 2, p < 0.05). Additionally, antibiotic resistance genes for quinolones, β-lactams, chloramphenicol, tetracyclines, and aminoglycosides were detected, with significantly higher prevalence in diarrheic calves. These findings demonstrate distinct microbial and antibiotic resistance profiles between healthy and diarrheic calves, emphasizing the importance of microbial management in controlling calf diarrhea.

Unusual Genomic and Biochemical Features of Paenarthrobacter lasiusi sp. nov-A Novel Bacterial Species Isolated from Lasius niger Anthill Soil.

The black garden ant (Lasius niger) is a widely distributed species across Europe, North America, and North Africa, playing a pivotal role in ecological processes within its diverse habitats. However, the microbiome associated with L. niger remains poorly investigated. In the present study, we isolated a novel species, Paenarthrobacter lasiusi, from the soil of the L. niger anthill. The genome of P. lasiusi S21 was sequenced, annotated, and searched for groups of genes of physiological, medical, and biotechnological importance. Subsequently, a series of microbiological, physiological, and biochemical experiments were conducted to characterize P. lasiusi S21 with respect to its sugar metabolism, antibiotic resistance profile, lipidome, and capacity for atmospheric nitrogen fixation, among others. A notable feature of the P. lasiusi S21 genome is the presence of two prophages, which may have horizontally transferred host genes involved in stress responses. P. lasiusi S21 synthesizes a number of lipids, including mono- and digalactosyldiacylglycerol, as well as steroid compounds that are typically found in eukaryotic organisms rather than prokaryotes. P. lasiusi S21 exhibits resistance to penicillins, lincosamides, fusidins, and oxazolidinones, despite the absence of specific genes conferring resistance to these antibiotics. Genomic data and physiological tests indicate that P. lasiusi S21 is nonpathogenic to humans. The genome of P. lasiusi S21 contains multiple operons involved in heavy metal metabolism and organic compound inactivation. Consequently, P. lasiusi represents a novel species with an intriguing evolutionary history, manifesting in distinctive genomic, metabolomic, and physiological characteristics. This species may have potential applications in the bioaugmentation of contaminated soils.

Antimicrobial resistance and molecular characterization of Escherichia coli and Staphylococcus aureus isolated from common fast foods in Gazipur city, Bangladesh

The increased trend in fast food consumption in Bangladesh has raised massive public health concerns about bacterial contamination and its resistance pattern to available antibiotics. This study aims to isolate, identify, and molecular characterization of Escherichia coli and Staphylococcus aureus from fast food samples sold within Gazipur City, Bangladesh, determine their antibiotic resistance profiles and virulence gene detection. A total of 120 samples including fuchka, burgers, sandwiches, and chicken roll were collected from different street vendors and restaurants in Gazipur City. Conventional microbiological methods were employed for the isolation and identification of anticipated isolates, while PCR techniques utilizing nuc and malB genes were implemented for molecular detection. Antibiotic sensitivity patterns were assessed using the Kirby-Bauer disc diffusion method and interpreted in accordance with CLSI guidelines. Out of 120 samples, 26 (21.66%) S. aureus and 22 (18.33%) E. coli were phenotypically detected by cultural and biochemical tests, whereas 12 (46.15%) nuc gene of S. aureus and 10 (45.45%) malB gene of E. coli were genotypically detected. The 6 nuc gene of S. aureus isolates exhibited resistance to cefoxitin, oxacillin, and penicillin (100%), and frequently moderate resistance to clindamycin (50%), whereas 83.33% were sensitive to doxycycline, gentamicin, azithromycin, and levofloxacin, respectively. Similarly, all E. coli isolates showed 100% resistance against erythromycin, ampicillin, and 80% resistance elicited against ceftazidime and tetracycline, respectively. Potentially significant for public health, this study found that fast food offered in restaurants was tainted with harmful S. aureus and E. coli isolates. The detection of MDR bacteria in fast food poses immense public health risks, and there is a dire need to improve food safety practices.