Resistance Patterns Research Articles

Antimicrobial resistance and clonal relationships of Salmonella enterica Serovar Gallinarum biovar pullorum strains isolated in China based on whole genome sequencing

BackgroundPullorum disease is a serious problem in many countries. Caused by Salmonella enterica serovar Gallinarum biovar Pullorum (S. Pullorum), it creates huge economic losses in the poultry industry. Although pullorum disease has been well-controlled in many developed countries, it is still a critical problem in developing countries. However, there is still a lack of information on S. Pullorum strains isolated from different regions and sources in China. The objective of this study was to supply the antimicrobial resistance patterns and clonal relationships of S. Pullorum from breeder chicken farms.MethodsIn this study, a total of 114 S. Pullorum strains recovered from 11 provinces and municipalities in China between 2020 and 2021 were selected. These 114 S. Pullorum strains were analyzed using whole genome sequencing (WGS). Antimicrobial resistance (AMR) was tested both by genotypic prediction using the WGS method and using disc diffusion to assess phenotypic AMR.ResultsThese 114 sequenced S. Pullorum strains were divided into three sequence types (STs), the dominant STs was ST92 (104/114). Further core genome multi-locus sequence typing analysis indicated that 114 S. Pullorum strains may have a close relationship, which could be clonally transmitted among different provinces and municipalities. Our results showed a close relationship between the S. Pullorum strains found in different regions, indicating these strains may have been transmitted in China a long time ago. Nearly all S. Pullorum strains 94.74% (n = 108) were resistant to at least one antimicrobial class, and 35.96% of the examined Salmonella strains were considered multiple drug resistant.ConclusionOverall, this study showed that S. Pullorum strains in China have a close genetic relationship in terms of antimicrobial resistance, suggesting widespread clonal transmission.

Epidemiological dynamics and molecular characterization of HIV drug resistance in eastern China from 2020 to 2023.

HIV drug resistance (HIVDR) has become a threat to the elimination of the AIDS epidemic due to the global scale-up of antiretroviral therapy (ART) for HIV-infected individuals. This study aims to investigate the epidemiological dynamics and molecular characterization of HIV pretreatment drug resistance (PDR) and acquired drug resistance (ADR) in Hangzhou, a developed region in China. An epidemiological survey combined with a molecular transmission network and Bayesian analysis was conducted. A total of 3,596 individuals with newly confirmed HIV infections (from 2020 to 2023) and 164 individuals with ART failure (from 2021 to 2023) were included. The molecular transmission network was used to identify key drug-resistant transmission clusters, while the Bayesian analysis was utilized to trace the origins and spread of these clusters. The overall prevalence of PDR was found to be 8.4% (303/3596). Among these cases, PDR to non-nucleoside reverse transcriptase inhibitors (NNRTIs) accounted for 4.7% (170/3596), significantly higher than the resistance observed for protease inhibitors (PIs; 2.8%, p < 0.001) and nucleoside reverse transcriptase inhibitors (NRTIs; 1.4%, p < 0.001). Multivariate logistic regression analysis revealed a significantly higher PDR value among individuals infected with the CRF07_BC subtype compared to those with the CRF08_BC subtype (aOR = 0.56, 95% CI = 0.359-0.859, p = 0.008). The molecular transmission network analysis identified the transmission of the drug resistance mutation (DRM) Q58E within the clusters of the CRF07_BC subtype. The Bayesian analysis suggested that these clusters were introduced into Hangzhou from Shenzhen between 2005 and 2012. Furthermore, the study highlighted 50.6% (83/164) prevalence of ADR among individuals experiencing ART failure. The combined molecular network analysis of virological failure and newly confirmed HIV infections indicated the transmission of the K103N mutation between these groups. In conclusion, targeted interventions may be necessary for specific subtypes and transmission clusters to control the spread of drug-resistant HIV. Continuous monitoring of resistance patterns is critical to inform treatment strategies and optimize ART regimens.

Silicosis predicts drug resistance and retreatment among tuberculosis patients in India: a secondary data analysis from Khambhat, Gujarat (2006–2022)

BackgroundIndia, with the highest global burden of tuberculosis (TB) and drug-resistant TB, aims to eliminate TB by 2025. Yet, limited evidence exists on drug resistance patterns and retreatment among patients with silico-tuberculosis. This study explores these patterns and assesses the impact of silicosis on TB retreatment in India.MethodsThis secondary data analysis stems from a larger retrospective cohort study conducted in Khambhat, Gujarat, between January 2006 and February 2022. It included 138 patients with silico-tuberculosis and 2,610 TB patients without silicosis. Data from the Nikshay TB information portal were linked with silicosis diagnosis reports from the Pneumoconiosis Board using the unique Nikshay ID as the linking variable. Drug-resistant TB was defined as resistance to any anti-TB drug recorded in Nikshay. Retreatment refers to TB patients who have previously undergone anti-TB treatment for one month or more and need further treatment. Recurrent TB denotes patients who were previously declared cured or had completed treatment but later tested positive for microbiologically confirmed TB. Multivariable logistic regression was used to determine the impact of co-prevalent silicosis on drug resistance and retreatment.ResultsPatients with silico-tuberculosis showed a higher proportion of retreatment compared to those without silicosis (55% vs. 23%, p < 0.001). Notably, 28% of patients with silico-tuberculosis were recurrent TB cases, compared to 11% among those without silicosis. Regarding drug resistance, the silico-tuberculosis group exhibited a higher rate (6% vs. 3%), largely due to rifampicin resistance (5% vs. 2%, p = 0.022). Co-prevalent silicosis was associated with a 2.5 times greater risk of drug-resistant TB (adjusted OR 2.5, 95% CI, 1.1–5.3; p = 0.021). Additionally, patients with silico-tuberculosis had a fourfold increased risk of retreatment for TB (adjusted OR 4, 95% CI, 3–6; p < 0.001).ConclusionsCo-prevalent silicosis significantly elevates the risk of drug resistance, recurrence, and retreatment among TB patients in India. This study indicates a need for improved treatment protocols and suggests that future research should focus on randomized controlled trials to evaluate appropriate anti-TB regimen and duration of therapy for this high-risk group. Given India’s goal to eliminate TB by 2025, addressing the challenges posed by silico-tuberculosis is critical.

Clinical and Drug Resistance Characteristics of Providencia Infections

Background: Providencia is a G ram-negative bacillus that most frequently colonizes the urinary tract and is often resistant to many antimicrobials. This study aimed to evaluate the resistance patterns of Providencia spp. and clinical outcomes due to the paucity of data. Methods: A multi-center, descriptive, retrospective chart review of adult patients with Providencia spp. infections was conducted from 1 January 2020 to 31 May 2022. The primary outcome was to describe the drug resistance patterns of Providencia spp. isolates. This study’s secondary outcome was to evaluate the clinical outcomes of patients with Providencia spp. infections. Results: Of the 312 patients screened, 244 were excluded primarily for polymicrobial infections. The mean age was 70 years, and 39 (56.5%) were males. Of the 68 included cases, 46 (67.6%) were P. stuartii, 20 (29.4%) were P. rettgeri, and 2 (2.9%) were P. alcalifaciens. The most common infections were bacteremia 38 (55.8%), followed by 27 (39.7%) urinary tract infections and 3 (4.4%) wound infections. In this study, 45 patients (65.2%) had urinary catheters. The primary antibiotics used for treatment consisted of ceftriaxone (25 (36.2%)), cefepime (20 (29%)), and meropenem (10 (14.5%)). Only 5 of 68 (7.2%) cases were multidrug- resistant and required meropenem. In total, 19 patients (27.1%) died during their admission, but none were related to Providencia infections. A total of 10 of the 68 patients (14.5%) were readmitted within 30 days for reasons unrelated to the progression or recurrence of Providencia infections. Conclusions:Providencia bacteremia is predominantly seen in elderly patients. Third- generation cephalosporins remain an appropriate choice of antibiotics for Providencia spp. Providencia stuartii was the only species with multidrug resistance.

Department-specific patterns of bacterial communities and antibiotic resistance in hospital indoor environments

The hospital indoor environment has a crucial impact on the microbial exposures that humans encounter. Resistance to antibiotics is a mechanism used by bacteria to develop resilience in indoor environments, and the widespread use of antibiotics has led to changes in the ecological function of resistance genes and their acquisition by pathogens. By integrating the 16S rRNA Illumina sequencing and high-throughput-quantitative PCR approaches with water and air dust samples across seven departments in Peking University Shenzhen Hospital, China, this study yields intriguing findings regarding the department-specific variations, correlations and source tracing of bacteria, antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) within the hospital indoor environment. A notable observation was the pivotal role played by seasonal variations in shaping the bacterial composition across the entire hospital indoor environment. Another department-specific finding was the correlation between ARGs and MGEs abundance, which was evident in the overall hospital indoor environment, but not found in the blood test room, ophthalmology, and gynecology departments. Notably, as an important source of bacteria and ARGs/MGEs for the blood test room, the gynecology department also presented a close link between bacterial communities and the presence of ARGs/MGEs. Additionally, the results reiterate the importance of surveillance and monitoring of antibiotic resistance, specifically in Legionella spp. in man-made water systems, and highlight the significance of understanding genetic elements like Tp614 involved in gene transfer and recombination, and their impact on antimicrobial treatment efficacy. Key points•The department-specific variations, correlations and source tracing of bacteria, ARGs, and MGEs were uncovered in the hospital’s indoor environment.•Although each department exhibited consistent seasonal impacts on bacterial compositions, the co-occurrence between the presence of ARGs and MGEs was exclusively evident in the emergency, surgery, pneumology and otolaryngology departments.•The gynecology department emerged as a crucial source of bacteria, ARGs and MGEs within the hospital. Additionally, it was found to exhibit a significant correlation between bacterial communities and the presence of ARGs and MGEs.

Assessment of Antimicrobial Resistance and Susceptibility Pattern of UTI-causing Microorganisms in Southern Punjab, Pakistan

Background: Bacterial resistance against antibiotics has become a global challenge and measures are needed to stop this. The aim of this study is to highlight this problem and to determine the antibiotic susceptibility pattern of organisms in Southern Punjab, Pakistan. Method: This descriptive cross-sectional study was conducted in Sheikh Zayed Medical Hospital, Rahim Yar Khan. The urine samples obtained from 4 different wards were sent for culture and sensitivity analysis. 9 antibiotics (Nitrofurantoin, Fosfomycin, Ciprofloxacin, Ceftriaxone, Trimethoprim-Sulfamethoxazole, Norfloxacin, Linezolid, Amoxicillin, and Imipenem) were tested against 5 isolated strains of uropathogens using Kirby Bauer disk diffusion test. The sensitivity reports were obtained, and data points were entered into a spreadsheet and analysed using SPSS. Results: Out of 101 samples of uropathogens that showed positive growths (42.08%), 53 (52.4%) were from male patients and 48 (47.5%) positive growths were from females. Escherichia Coli had the highest positive growths (58%) followed by Pseudomonas (19%) Klebsiella (13%), Staphylococcus Aureus (7%) and Coagulase-negative staphylococci (3%). Imipenem was the most sensitive drug whereas the highest resistance by organisms was developed against TMP-SMX. No significant association(p&gt;0.05) was found between any of the anti-microbial drugs and Escherichia coli, gram-positive uropathogens, and gram negative uropathogens. Conclusion: The high increasing rate of broad-spectrum antibiotics resistance suggests that diagnostic and culture tests should be encouraged in hospitals. Based on these test results, appropriate antibiotics should be prescribed. The limitations include the inability to distinguish between nosocomial and community-acquired urinary tract infections and also did not consider other demographic factors like age.

Genetic basis of resistance to Cry1Ac in Rachiplusia nu (Lepidoptera: Noctuidae): inheritance mode, cross-resistance patterns and fitness cost.

Rachiplusia nu (Guenée) was historically a secondary soybean pest in Brazil, but a key soybean pest in Argentina. From 2021 onwards, injury caused by R. nu has been reported in soybean that expresses the Cry1Ac toxin from Bacillus thuringiensis (Berliner) in both countries. In this study, we selected resistant and susceptible strains of R. nu to Cry1Ac using Cry1Ac-containing leaf tissue and characterized the inheritance of resistance, cross-resistance patterns and fitness cost. Neonates of the Cry1Ac-resistant strain of R. nu were able to develop on Cry1Ac soybean leaves and emerge as fertile adults, while neonates from the susceptible and heterozygous strains did not survive beyond 10 days. The resistance ratio to Cry1Ac estimated in diet-overlay bioassays in the resistant strain was > 736.92-fold. The inheritance pattern of Cry1Ac resistance in R. nu was characterized as autosomal recessive and monogenic. The Cry1Ac-resistant strain of R. nu also exhibited high resistance to Cry1A.105 (resistance ratio > 159.87-fold), but negligible resistance to Cry2Ab2 (resistance ratio = 1.25-fold). Life history data showed that the resistance to Cry1Ac in R. nu is not associated with a substantial fitness cost. The inheritance pattern of Cry1Ac resistance in R. nu is autosomal recessive, monogenic and not associated with obvious fitness costs. Cross-resistance occurred between Cry1Ac and Cry1A.105 in R. nu but not between Cry1Ac and Cry2Ab2, indicating that Cry1A.105/Cry2Ab2/Cry1Ac soybean is a valuable tool to manage Cry1Ac resistance in R. nu. This is the first study reporting the genetic basis of Cry1Ac resistance in R. nu. © 2024 Society of Chemical Industry. Published by John Wiley & Sons Ltd.

Analyzing Antibiotic Resistance: A Comparative Study of E. coli Isolates from Wastewater and Clinical UTI Samples at a University Community in Grenada, West Indies

Abstract Introduction/Objective The rise of antibiotic resistance poses a significant global health threat, needing a robust monitoring system to track its emergence and spread. However, most developing countries lack the infrastructure to monitor such resistance effectively. Wastewater-based epidemiology (WBE) has been proven effective in surveilling various outbreaks and offers a promising method for monitoring antibiotic resistance at the community level. This study aims to assess and compare the antibiotic resistance of Escherichia coli isolated from raw wastewater with those isolated from clinical urinary tract infection (UTI) samples from the same community. Methods/Case Report Conducted from January 2022 to October 2023, this study analyzed antibiogram data from eighty-six Escherichia coli isolates sourced from wastewater and thirty-four isolates derived from clinical urinary tract infections (UTIs). The clinical samples were obtained and processed at the Clinical Microbiology Laboratory of a university campus. The isolates were evaluated against the eleven most prescribed antibiotics for UTIs in the University Clinic including: Amoxicillin/Clavulanic Acid, Ampicillin, Cefazolin, Cefoxitin, Ceftriaxone, Cefuroxime, Ciprofloxacin, Gentamicin, Nalidixic Acid, Nitrofurantoin, and Sulfamethoxazole-trimethoprim. Results (if a Case Study enter NA) Explaining the observed trends in both wastewater and clinical samples from the perspective of AWaRE-WHO classification (Access, Watch, Reserve), we see similar trends of resistance in both data sets. A) The antibiotics used in the Access category (Empiric first or second choice for treatment of most common infections) demonstrates similar resistance patterns for both wastewater and clinical isolates except for Nitrofurantoin. B) The antibiotics used in the Watch category (Antibiotics that have higher toxicity issues and higher potential to negatively impact AMR) resistance pattern shows negligible risk in the university community evaluated. Conclusion It is recommended that the university clinic prescribe Nitrofurantoin as the last antibiotic from the Access list to the university community to treat UTI patients. Furthermore, WBE is a useful tool to determine patterns of resistance under the studied settings.

Impact of an enhanced anti-infection prophylaxis strategy for pancreatoduodenectomy: a single centre analysis

Introduction Surgical site infection (SSI) after pancreatoduodenectomy (PD) is a significant concern. Targeted antibiotic prophylaxis (pAP) has been tested to mitigate antibiotic resistance patterns, especially after preoperative bile duct stenting. The aim of this study was to investigate the effect of enhanced anti-infective prophylaxis (EAP) on the incidence of superficial and intraabdominal SSI.MethodsAll patients who underwent PD at a single centre between May 2018 and May 2021 were retrospectively analysed. A control cohort of patients who received pAP with intravenous cefuroxime and metronidazole and routine intraoperative abdominal lavage according to the surgeons’ preferences. Since March 2020, pAP has been changed to piperacillin/tazobactam according to local resistance patterns and combined with routine intraoperative extended abdominal lavage (EIPL). Preoperative selective decontamination of the digestive tract (SDD) has been applied routinely since Jan 2019.ResultsIn total, 163 patients were included. The standard (n = 100) and EAP (n = 63) groups did not significantly differ with regard to pertinent patient and operative characteristics. In the EAP group, the rates of SSI (14% vs. 37%, p = 0.002, total rate: 28%) and urinary tract infection (24% vs. 8%, p = 0.011, total rate 18%) were significantly lower. Other septic complications were not significantly different. In addition, the risk of developing gastrointestinal bleeding and delayed gastric emptying was significantly lower in the EAP group. Multivariate analysis showed that an age > 67 years was a significant risk factor for SSI.ConclusionThe results indicate that enhanced anti-infective prophylaxis may significantly decrease the incidence of SSI in patients after PD.

Molecular epidemiology of diabetic foot ulcers

Abstract Introduction/Objective The study accessed the prevalence of Escherichia coli in diabetic diabetic foot infection(DFI) and diabetic foot osteomyelitis(DFOM).A single retrospective single centre was conducted on patients diagnosed with E.coli isolated from deep DFI and DFOM at Komfo Anokye Teaching Hospital over 2 year period. Methods/Case Report Phylogenetic backgrounds,virulence factors(VFs) and antibiotic resistance profiles were determined.Whole genome analysis of E.coli strains isolated from same periods were performed. From two years study period,35 E.coli strains isolated from 33 patients were analysed,73% were isolated from DFOM Results (if a Case Study enter NA) The majority of the strains belonged to the virulent B2 and D phylogenetic groups(82%).These isolates exhibited a significant higher average of VFs number greater than strains belonging to the other groups (p&amp;lt;0.0001).papG2 gene was significantly more detected in strains belonging to B2 phylogeny isolated from DFI compared to DFOM(p=0.003) The most prevalent antibiotic resistance pattern was observed for ampicillin(82%)cotrimoxazole(45%) and ciprofloxacin (33%).The genome analysis of strains isolated at two periods in DFOM showed a decrease of the genome size and this decrease was more important for the strains isolated at 9 months(versus 4 months) Conclusion Shared mutation on the putative acy-CoA dehydrogenase-encoding gene aidB was observed on both strains. E.coli isolated from DFOM werA shared highly genetically diverse with different pathogenicity traits.Their adaptation on the bone structure could require genome reduction and some important modifications in the balance virulence and resistance of the bacteria

Bacterial isolates from drinking water river sources exhibit multi-drug resistant trait.

Freshwater habitat is a natural reservoir for antimicrobial resistance (AMR). AMR poses serious human, animal, and environmental public health threats. This study aimed to evaluate the physicochemical and microbiological quality of five selected rivers (Apitipiti 1, Apitipiti 2, Apitipiti 3, Sogidi, and Aba Apa Akinmorin) in Oyo town, Nigeria, as well as the antibiotic resistance pattern of isolated bacterial species, using conventional methods. Most physicochemical parameters were within WHO and NIS permissible limits. Pearson's correlation matrix indicated that there were significant (p < 0.05) interactions among pH, electrical conductivity, temperature, sulphate and chloride salts, and BOD and COD. A total of thirty-two (32) bacterial species were isolated and identified as: Aeromonas (9), Bacillus (2), Corynebacterium (13), Lactobacillus (1), Pseudomonas (2), Staphylococcus (4), and Streptococcus (1). Of the rivers, Sogidi had the highest microbial load (6.36 log CFU/mL) while Apititipiti 1 had the lowest (5.76 log CFU/mL). With regard to antibiotic sensitivity, 81.8% were multidrug-resistant, with Corynebacterium kutscheri and Aeromonas spp. isolated from Apitipiti 2 and Aba Apa Akinmorin rivers, respectively, exhibiting a relatively high antibiotic resistance of 90.9%. This study reveals that these rivers may be unfit for consumption as multidrug-resistant bacteria of public health risk were associated with them.

Molecular and Microbiological Characterization of Candida auris Strains Isolated from Colonized and Infected Patients in a New York City Tertiary Care Center

Abstract Candida auris is a multidrug resistant pathogen that causes healthcare associated invasive infections and outbreaks with high mortality rates, often involving intensive care units (ICU). High rates of C. auris colonization among patients in ICUs are associated with increased risk of subsequent C. auris hospital-acquired infections. In this study, microbiological characteristics, and antifungal susceptibility patterns of C. auris isolates collected between January and December 2023 were investigated. Whole-genome sequencing was used to examine the genetic variation and molecular epidemiological characteristics. During the study period, a total of 20 patients were found to be colonized with C. auris by three site skin swab and eight of these patients subsequently developed invasive infection with C. auris. Among patients with both colonization and infection, all invasive isolates were closely related genetically to colonizing isolates and belonged to clade I. Candidemia was the most common infection identified in 4/8 (50%) patients. All isolates were resistant to fluconazole and thirteen isolates from six patients were resistant to amphotericin B. Paired isolates from patients with both colonization and invasive infection showed the same antifungal resistance patterns. All isolates had the ERG11 p.K143R mutation known to cause fluconazole resistance. Three isolates from one patient with a FKS1 hotspot region 3 p.M690I mutation were resistant to caspofungin and two isolates from one patient with a FKS1 hotspot region 2 p.R1354H mutation were resistant to caspofungin, anidulafungin and micafungin. Our study demonstrates that colonization with C. auris is associated with increased risk of infection by the same strain amongst critical ill patients. C. auris screening and implementation of adequate infection control measures are urgently needed to prevent the dissemination of C. auris infections.

Bacterial Contamination of Donor Blood Units in a Ghanaian Blood Bank: A Critical Concern for Transfusion Safety

Abstract Introduction/Objective Background: Blood transfusions, while life-saving, pose a significant risk to patient safety, with transfusion-associated bacterial sepsis emerging as a persistent and potentially fatal threat. The prevalence and severity of bacterial contamination in donor blood units necessitate regular surveillance to ensure safe and effective transfusion therapy. Aim This study aimed to identify and assess the susceptibility of bacterial isolates in whole blood donor units at the blood bank of Cape Coast Teaching Hospital in the Central Region of Ghana. Methods/Case Report Method(s): One hundred and three (103) units of stored whole blood units, declared safe for transfusion (testing negative for HIV I&amp;II, HBsAg, HCV, and syphilis), were inoculated into Brain Heart Infusion Broth and incubated for 24 hours. The inoculated broths were then cultured on MacConkey agar (MAC), Chocolate agar (CHOC), and Blood agar. Gram-negative and Gram-positive isolates were identified using standard biochemical tests. Antimicrobial susceptibility testing was performed using the disc diffusion method. Results (if a Case Study enter NA) Results: Of the 103 donor blood units tested, 33 (32.03%) were found to have bacterial isolates. Gram-positive organisms accounted for 67.14% of the isolates, including Coagulase negative Staphylococcus, Bacillus spp, and S. aureus. Gram-negative bacteria constituted 32.86% of the isolates, with Citrobacter freundii, Serratia marcescens, E. coli, and Providencia stuartii identified. Notably, 62.9% of the bacterial isolates were skin commensals, while 25.7% were of enteric origin and 11.4% were of nosocomial origin. Resistance to commonly used antibiotics varied among isolates, with Coagulase-negative Staphylococcus exhibiting resistance to amoxicillin (92.86%) and erythromycin (76.19%), while Citrobacter freundii showed resistance to levofloxacin (75.00%) and ofloxacin (75.00%). Conclusion Conclusion(s): The high incidence of bacterial contamination in donor blood units highlights the need for improved phlebotomy procedures and decontamination practices at blood banks in Ghana to reduce the risk of sepsis in transfusion recipients. Furthermore, this study provides valuable information regarding antibiotic resistance patterns in bacterial isolates, emphasizing the importance of antibiotic stewardship in Ghana. In conclusion, this study underscores the urgency of addressing bacterial contamination in donor blood units in Ghanaian blood banks to enhance transfusion safety.

Exploring the antibiotic resistance of Listeria monocytogenes in food environments - a review.

Listeria monocytogenes, a resilient bacterium in diverse food conditions, such as refrigeration, reduced water activity and low pH, poses a significant threat to the food industry and public health. In recent years, it has been documented an increase in the antibiotic resistance of zoonotic pathogens, including L. monocytogenes. This review provides new insight into the molecular mechanisms involved in both intrinsic and acquired antibiotic resistance of L. monocytogenes with an emphasis on the effect of different environmental and food-related factors. It also explores the relationship of these resistance mechanisms with virulence factors. An analysis of literature data (2009-2021) was conducted to investigate statistically and graphically potential associations between specific antibiotic resistance patterns in the pathogen and food categories using an unbiased variance analysis. The results evidenced that food type had an influence on the antibiotic resistance profiles of L. monocytogenes, with meat and vegetables being the food categories exhibiting the most prevalent profiles. The frequent detection of resistance to ampicillin, penicillin, and tetracycline (non-intrinsic resistances) indicates that specific processing conditions along the food chain may induce them. Many questions remain about the impact of food chain factors (e.g. thermal treatments, cold chain, preservatives, etc.) and food type (low pH, reduced water activity, etc.) on the antibiotic resistance patterns of the pathogen, particularly concerning food-related sources, the resistance mechanisms involved (e.g. cross-protection, horizontal gene transfer, etc.), and the evolutionary processes of antibiotic-resistant microbial populations. Metagenomics, in addition to other -omics technologies (metabolomics and transcriptomics), allows a better understanding of the processes involved in the acquisition of resistance.

Resistance patterns, virulence determinants, and biofilm genes of multidrug-resistant Pseudomonas aeruginosa isolated from fish and fish handlers

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic bacterium that is widely distributed in aquatic environments and causes major economic losses in fish and public health hazards.This study aimed to identify the occurrence of P. aeruginosa in samples collected from fish and fish handlers, and to investigate the antimicrobial susceptibility, virulence determinants, and biofilm genes of P. aeruginosa isolates. A total of 276 samples were cross-sectionally collected from Nile tilapia (53), Golden grey mullet (52), Mediterranean horse mackerel (50), Striped red mullet (71), and fish handlers (50) at five different retail fish markets in Damietta Governorate, Egypt. Pseudomonas species (spp.) were biochemically identified in 57.9% of the total examined samples. Peudomonas aeruginosa were the most prevalent species isolated from the fish and human samples via PCR technique. Peudomonas aeruginosa isolates exhibited full resistance (100%) to tobramycin (TOB), gentamicin (CN), and colistin (CL), with a high level of susceptibility (88.5%) to imipenem (IPM) using the disk diffusion method. Most P. aeruginosa isolates (84.6%) exhibited drug resistance, with 61.5% were multidrug resistance (MDR) and 23.1% were extensive drug resistance (XDR). Most isolates had at least four virulence-associated genes (lasB, toxA, exoU, and oprL) and three biofilm genes (psIA, peIA, and lasR) by using uniplex PCR. The lasI, and rhlR Quorum Sensing (QS) genes were identified in 84.6% and 61.5% in the examined P. aeruginosa isolates, respectively. The highest mortality rate in Nile tilapia experimentally infected with P. aeruginosa isolate encoding most of virulent genes. Multivariate analyses revealed high heterogeneity among the examined isolates. This study revealed the emergence of virulent and drug resistant P. aeruginosa isolates in fish, poses high risks to consumers and food. Thus, strict hygienic measures should be considered when catching, handling, and storing fish, in addition to the routine application of antimicrobial susceptibility testing.

Impact of discontinuing routine fluoroquinolone prophylaxis in neutropenic allogeneic haematopoietic stem cell transplant recipients: an observational study.

Uncertainty exists as to the role of fluoroquinolone (FQ) prophylaxis for patients undergoing allogeneic haematopoietic stem cell transplantation (HSCT) in the era of rising antibiotic resistance. We aimed to evaluate rates of bloodstream infections (BSI), resistance patterns and outcomes of patients after discontinuing routine FQ prophylaxis administration. All adult recipients of first HSCT from 2017 to 2020 were retrospectively included and classified according to time of HSCT as FQ group (HSCT January 2017-December 2018) or no FQ group (January 2019-December 2020). The primary outcome was Gram-negative (GN) BSI from day -7 to 30 days post-HSCT. The independent association between the study period and BSI was assessed using survival analysis, and adjusting for confounders. We included 254 patients, 130 (51%) and 124 (49%) in the FQ and no FQ groups, respectively. Compared to the FQ group, no FQ had significantly more GN BSI (21% versus 33%, P = 0.027) and the median time to first GN BSI was significantly shorter [4 (IQR 1-8) days versus 6 (1-10) days, P = 0.009]. Following adjustment, FQ prophylaxis remained associated with lower hazard for GN BSI (hazard ratio 0.57, 95% CI 0.34-0.93). Eighty-two GN BSI episodes had FQ susceptibility testing. More GN BSI episodes were FQ resistant in the FQ group (68.9% versus 41.6%, P = 0.021). No significant difference was found for 30-day mortality, time to first febrile neutropenia and time to first broad-spectrum antibiotics between the groups (P was not significant). FQ prophylaxis is associated with fewer GN BSI in the early post-HSCT period even in high FQ resistance settings, with FQ resistance rates reaching >60% following prophylaxis.

Molecular Epidemiology and AMR Perspective of Diarrhoeagenic Escherichia coli in Africa: A Systematic Review and Meta-analysis.

Diarrhoeagenic Escherichia coli (DEC) persistently challenges public health in Africa, contributing substantially to the diarrhoeal disease burden. This systematic review and meta-analysis illuminate the distribution and antimicrobial resistance (AMR) patterns of DEC pathotypes across the continent. The review selectively focused on pathotype-specific studies reporting prevalence and/or AMR of human-derived DEC pathotypes from African nations, excluding data from extra-intestinal, animal, and environmental sources and studies focused on drug and mechanism experiments. Pertinent studies were retrieved from SCOPUS, PubMed, and EBSCOhost, processed with Covidence, and screened in alignment with PRISMA guidelines. The reviewed studies were predominantly hospital-based (80%) and paediatric-focused (91%), with a meagre 4.4% documenting DEC outbreaks. Seven DEC pathotypes were discerned, with Enteroaggregative E. coli (EAEC) being notably prevalent (43%, 95% CI 30-55%) and Enteroinvasive E. coli (EIEC) least prevalent (24%, 95% CI 17-32%). Identified non-susceptibilities were noted against essential antibiotics including ciprofloxacin, ceftriaxone, and ampicillin, while instances of carbapenem and Extended-Spectrum ß-Lactamase (ESBL) resistance were scarce. Despite sporadic data on DEC prevalence and AMR in Africa, particularly in community settings, a palpable gap remains in real-time outbreak surveillance and comprehensive data documentation. Augmenting surveillance and embracing advancements in molecular/genomic characterisation techniques are crucial to precisely discerning DEC's actual impact and resistance continuum in Africa.

Characterization of Physio-Biochemical Properties for Leaf Rust in Wheat Associated with Yield Losses and Disease Resistance Patterns

Characterization of Physio-Biochemical Properties for Leaf Rust in Wheat Associated with Yield Losses and Disease Resistance Patterns

FREQUENCY OF PIPERACILLIN/TAZOBACTAM RESISTANCE IN SPONTANEOUS BACTERIAL PERITONITIS PATIENTS

Spontaneous bacterial peritonitis (SBP) is a serious infection in patients with chronic liver disease, requiring prompt antibiotic therapy. Due to growing resistance to first-line antibiotics like ceftriaxone, piperacillin/tazobactam is often used as a second-line treatment. However, emerging resistance to piperacillin/tazobactam poses a significant clinical challenge. Identifying local resistance patterns is crucial for optimizing treatment, particularly in resource-limited settings like Peshawar, Pakistan. Objective: To determine the frequency of piperacillin/tazobactam resistance among patients with spontaneous bacterial peritonitis at a tertiary care hospital in Peshawar, Pakistan. Methods: This cross-sectional study was conducted over five months at Lady Reading Hospital, Peshawar from 18th April to 18th September. A total of 169 patients aged 16 to 75 years with SBP secondary to chronic liver disease were included using non-probability consecutive sampling. Demographic and clinical data were collected, and ascitic fluid samples were cultured to assess resistance to piperacillin/tazobactam. Data were analyzed using descriptive statistics and chi-square tests to examine associations. A p-value &lt; 0.05 was considered statistically significant. Results: Piperacillin/tazobactam resistance was found in 9.5% (16/169) of SBP patients. Resistance was observed in 8.0% (7/88) of Escherichia coli isolates and 11.1% (9/81) of other bacterial isolates (p = 0.04). Resistance rates were slightly higher in the 46–75 age group (11.0%, 11/100) compared to the 16–45 age group (7.3%, 5/69). Male patients had a resistance rate of 10.2% (11/108), while female patients showed 8.2% (5/61). Conclusion: This study highlights significant resistance to piperacillin/tazobactam among SBP patients in Peshawar, particularly in non-E. coli bacteria. These findings underline the need for personalized antibiotic regimens and ongoing surveillance to address growing antimicrobial resistance in chronic liver disease patients.

Low penicillin susceptibility in Streptococcus mitis/oralis from bloodstream infections in pediatric populations.

Existing research primarily focuses on specific populations, such as those with hematopathy or tumors, who experience Streptococcus mitis/oralis bacteremia. Limited studies have been conducted on the prevalence of bloodstream infections caused by S. mitis/oralis across the entire pediatric population. It was found that the contamination rate of S. mitis/oralis isolated from blood cultures was notably high in our study. Therefore, this study evaluated the clinical characteristics and drug resistance patterns of bloodstream infections caused by S. mitis/oralis across the entire pediatric populations, explicitly excluding cases of blood culture contamination. The observed low susceptibility rate to penicillin, coupled with the emergence of multi-drug-resistant strains, underscores the imperative for continuous monitoring of the evolving antimicrobial resistance in S. mitis/oralis.