Environmental Strains Research Articles

Genetic diversity, drug resistance, and biofilm formation in Klebsiella pneumoniae associated with nosocomial infection in Pelotas, RS, Brazil.

Antibiotic resistance and the potential persistence of Klebsiella pneumoniae strains in hospital environments is an important challenge for human medicine. This research aims to detect resistance to antibiotics, biofilm formation, and the genetic pattern among clinical isolates associated with nosocomial infection obtained from a university hospital in the city of Pelotas, RS, Brazil. Twenty-eight isolates were identified at the species level by polymerase chain reaction (PCR) and were characterized regarding the profile of biofilm formation and antibiotic resistance. The genetic relationship was determined through pulsed-field gel electrophoresis (PFGE). The antibiotic resistance profile was made following the standards established by CLSI. All clinical isolates included in this study were confirmed as belonging to the species K. pneumoniae, 96.42% were considered strong biofilm formers and all were positive in the Congo Red agar (CRA) test. Thus, 64.29% of isolates were classified as multidrug-resistant (MDR), 25% as extensively drug-resistant (XDR), and 7.14% as pandrug-resistant (PDR). PFGE fingerprint analysis revealed 18 clones and of these, 15 have a unique pattern and another three were groups with patterns > 80% similarity. The clinical isolates used were collected over two years and revealed a genetic relationship. The same clone was identified in different types of samples and different years, demonstrating the permanence of the strain in the hospital environment. Our results reaffirm the need for greater measures of control and disinfection within the hospital environment, and the priority of therapeutic measures to contain the propagation of K. pneumoniae.

Genomic Insights into Vibrio parahaemolyticus from Southern Korea: Pathogenicity, Antimicrobial Resistance, and Phylogenetic Distinctions

Vibrio parahaemolyticus, a significant cause of gastroenteritis and a growing public health concern, has become increasingly prevalent owing to the rise in ocean temperatures driven by climate change. This study aimed to characterize the genetic diversity, pathogenic potential, and antimicrobial resistance (AMR) profiles of V. parahaemolyticus strains isolated from the southern coastal region of Korea. Using whole genome sequencing (WGS) and advanced bioinformatics tools, we identified novel sequence types through multilocus sequence typing and serotyped isolates using the VPsero database. Pathogenic genes, such as tdh and trh, were detected in only a few isolates, suggesting the involvement of alternative virulence mechanisms in the pathogenicity of these strains. An in silico analysis revealed widespread AMR, particularly against beta-lactams, chloramphenicol, and tetracycline antibiotics, underscoring the public health threats posed by these strains. A phylogenetic analysis revealed no significant clustering by geographic origin, year, or strain source, although most clinical and environmental strains were not closely related at lower phylogenetic branches. These findings highlight the importance of continued genomic surveillance and strict regulations regarding antibiotic use in marine environments. Moreover, this study suggests that integrating WGS data with epidemiological models could enhance the prediction of the emerging virulent strains and support effective outbreak management strategies.

Development of a loop-mediated amplification (Lamp) assay for detection of environmental <i>Pseudomonas aeruginosa</i>

Pseudomonas aeruginosa (P. aeruginosa) is a common environmental bacterium found in various habitats, including water and soil. Rapid detection of this microorganism is essential for monitoring environmental contamination and assessing its potential impact on ecosystems and public health. This study aimed to develop a high-efficiency loop-mediated isothermal amplification (LAMP) assay targeting a P. aeruginosa-specific gene encoding a hypothetical protein (GenBank ID: 882161). The study involved two main parts: 1) Isolation and identification of P. aeruginosa from environmental samples, and 2) Evaluation of the established LAMP assay on these environmental P. aeruginosa isolates. A total of 52 samples were collected from various geographical regions in Ho Chi Minh City, with 50 samples (96%) containing Pseudomonas species, characterized as rod-shaped, Gram-negative bacteria growing on selective media. Following duplex PCR screening, 14 P. aeruginosa-like environmental strains were isolated, and 5 randomly selected isolates were confirmed as P. aeruginosa through 16S rRNA sequencing. The LAMP assay was optimized at 60°C, 63°C, and 65°C for 30 and 45 minutes, using specific primers, and tested on all five confirmed P. aeruginosa isolates. The results demonstrated that the LAMP assay was highly specific (100%) for detecting environmental P. aeruginosa, with a detection limit of 1 pg/μL. In conclusion, P. aeruginosa is prevalent in the environment, and the developed LAMP assay shows strong potential for identifying environmental P. aeruginosa isolates.

Utilization of Pseudomonas fluorescens Bacteria in Weed Control and Phosphate Supply in Oil Palm (Elais Guineensis Jacq.) Plantations

With growing environmental concerns, sustainable management practices in oil palm plantations are becoming increasingly essential. This review examines the potential of Pseudomonas fluorescens as a biological agent for both weed control and phosphate solubilization in oil palm (Elaeis guineensis) cultivation. A systematic literature search was conducted across Google Scholar, Scopus, and ScienceDirect databases, focusing on studies published between 2007 and 2023. Studies that investigated the role of Pseudomonas fluorescens in enhancing plant growth through weed suppression or improving phosphate uptake were selected. The findings reveal that Pseudomonas fluorescens can significantly benefit plant health by minimizing weed competition and enhancing the availability of phosphorus in the soil. However, challenges such as the variability in environmental conditions, strain specificity, and scalability of application persist. The review highlights the importance of further field trials and experimental research to refine the practical use of Pseudomonas fluorescens in achieving more sustainable oil palm production.

Wings of progress: The economic and social impacts of low-cost carriers in the Philippines

Low-cost carriers (LCCs) have become a significant force in the Philippine aviation industry, providing affordable air travel and contributing to regional economic and social development. However, the full extent of their economic, social, environmental, and infrastructural impacts has not been comprehensively studied. This study aims to evaluate the economic and social implications of LCCs in the Philippines, focusing on tourism growth, job creation, business development, and the accessibility and mobility of the population. The study also explores environmental challenges and infrastructural strains caused by the expansion of LCC operations. A mixed-methods approach was employed, incorporating quantitative data analysis of tourism statistics, employment rates, business growth, and regional economic output. Qualitative data were collected through interviews and surveys with stakeholders, including passengers, local businesses, government officials, and environmental agencies. Statistical tools such as regression analysis and chi-square tests were used to determine significance levels in the findings. The results demonstrate that LCCs have contributed significantly to regional economic growth, with a 25% increase in tourist arrivals and a 30% rise in tourism revenue. Social impacts include enhanced travel accessibility, increased cultural exchange, and improved quality of life. However, environmental challenges, such as a 15% increase in carbon emissions, highlight the need for sustainable practices. The study recommends further investment in airport infrastructure, implementation of sustainable aviation practices, and ongoing government support for regional tourism. Future studies should focus on long-term environmental impacts and strategies for reducing carbon footprints.

Phylogenetic Characterization of Vibrio vulnificus Strains from Oysters and its Comparison with Clinical vcgE Genotype Strain.

Twenty-one environmental Vibrio vulnificus strains from the Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) bacteria collection, 20 of them isolated from oyster samples and 1 from a reported clinical case, were sequenced to analyze the genomic divergence between 2 genotypes, E-genotype and C-genotype, proposed by various groups to distinguish clinical (C) from environmental (E) V. vulnificus strains. As indicated in previous analyses of PFGE, MLST, and rtxA, 9 of the CICESE isolates were identified as vcgE, compared with 12 as vcgC. Separation of the genotypes into these 2 groups was confirmed in this study, based on the presence of certain genes in the 21 genomes, the presence of virulence factors, and rtxA sequencing. Most genomes from oyster isolates expressed rtxA-C type, with the exception being rtxA-M type detected in CICESE-594 a vcgE strain isolated from a clinical case. Although several genetic approaches clearly indicate differences between the C- and E-genotypes, none of them, including those in this study, can highlight a single factor that could be used to indicate the potential pathogenicity of V. vulnificus isolated from oysters.

Emergence of polymyxin-resistant Yersinia enterocolitica strains in natural aquatic environments

Aquatic environments serve as ideal reservoirs for antibiotic-resistant bacteria and resistance genes. However, the presence of polymyxin-resistant Yersinia enterocolitica, the pathogen responsible for human yersiniosis, in aquatic environments remains poorly understood. Herein, we isolated polymyxin-resistant Y. enterocolitica strains from natural water for the first time. In addition to intrinsic resistance to ampicillin and cefazolin, the strains demonstrated high resistance to polymyxin B and polymyxin E. All isolates were capable of biofilm production and exerted high virulent effects in Galleria mellonella, with 90% mortality occurring within 48 h post-infection. Furthermore, whole genome sequencing identified 26 antibiotic resistance genes, including polymyxin resistance determinants (arnA and PmrF), beta-lactam resistance determinants (vatF and blaA), and 60 virulence genes such as yaxA and yaxB in Y. enterocolitica isolates. Notably, phylogenetic analysis revealed that Y. enterocolitica involved multilocus sequence types ST937 and ST631, which were clustered with strains isolated from a human in the United States or swine in China. The close relatedness to clinical isolates suggests that polymyxin-resistant Y. enterocolitica may pose considerable health risk to humans. Our findings provide evidence of the presence of polymyxin-resistant Y. enterocolitica in aquatic environments and raise concerns about health risks due to their potential high virulence.

Comprehensive Study on Amino‐Modified Salix Wood Powder Membranes: Preparation, Adsorption Mechanism and Desorption Conditions for Efficient Chlortetracycline Removal

The wastewater of Chlortetracycline (CTC) poses a threat to the balance of aquatic ecosystems, promoting the formation and dissemination of antibiotic‐resistant bacterial strains in the aquatic environment. Moreover, such pollution can directly or indirectly affect human health through water sources, exacerbating the issue of antibiotic resistance. In response to this pollution challenge, Amino‐modified salix wood powder membrane(ASPPM) was prepared by phase transition and wet spinning techniques, aimed at removing CTC from water bodies. Adsorption experiment results show that the ASPPM maximum adsorption capacity for CTC is 458.99 mg/g. In the desorption process, the highest desorption rate of ASPPM for CTC was 79.65%. By fitting pseudo‐first‐order and pseudo‐second‐order kinetic models, it is found that the adsorption process of ASPPM on CTC is predominantly chemical adsorption. By fitting three isotherm models, it is found that the adsorption behavior of ASPPM on CTC is more in accordance with the Freundlich isotherm model, indicating multilayer adsorption on heterogeneous surfaces. The preparation of ASPPM study not only transforms renewable biomass materials into effective tools for environmental purification but also offers a cost‐effective new approach for sustainable environmental management, expanding the application of biomass materials in the field of environmental protection.

Genome-wide comparative analysis of clinical and environmental strains of the opportunistic pathogen Paracoccus yeei (Alphaproteobacteria).

Paracoccus yeei is the first species in the genus Paracoccus to be implicated in opportunistic infections in humans. As a result, P. yeei strains provide a valuable model for exploring how bacteria shift from a saprophytic to a pathogenic lifestyle, as well as for investigating the role of horizontally transferred DNA in this transition. In order to gain deeper insights into the unique characteristics of this bacterium and the molecular mechanisms underlying its opportunistic behavior, a comparative physiological and genomic analysis of P. yeei strains was performed. Complete genomic sequences of 7 P. yeei isolates (both clinical and environmental) were obtained and analyzed. All genomes have a multipartite structure comprising numerous extrachromosomal replicons (59 different ECRs in total), including large chromids of the DnaA-like and RepB families. Within the mobile part of the P. yeei genomes (ECRs and transposable elements, TEs), a novel non-autonomous MITE-type element was identified. Detailed genus-wide comparative genomic analysis permitted the identification of P. yeei-specific genes, including several putative virulence determinants. One of these, the URE gene cluster, determines the ureolytic activity of P. yeei strains-a unique feature among Paracoccus spp. This activity is induced by the inclusion of urea in the growth medium and is dependent on the presence of an intact nikR regulatory gene, which presumably regulates expression of nickel (urease cofactor) transporter genes. This in-depth comparative analysis provides a detailed insight into the structure, composition and properties of P. yeei genomes. Several predicted virulence determinants (including URE gene clusters) were identified within ECRs, indicating an important role for the flexible genome in determining the opportunistic properties of this bacterium.

Assessing the role of environment in Pseudomonas aeruginosa healthcare-associated bloodstream infections: a one-year prospective survey

ObjectiveTo prospectively investigate the role of hospital environment in Pseudomonas aeruginosa (Pa) nosocomial bloodstream infections (BSIs) during one year in a tertiary-care hospital. MethodsClinical records of patients presenting Pa-BSIs after >48h of hospitalization were investigated to confirm the nosocomial character of BSIs and identify the way of entry and risk factors. Environmental investigations were performed to track Pa source/reservoir along the pathway of cares. Clinical and environmental strains were compared by whole-genome sequencing to identify the path of contamination from hospital environment to patients. Results53 episodes of BSIs in 49 patients were considered as nosocomial, mostly involving men (73%), with an average age of 62.4, immunosuppressed in over 40% of cases, and after previous antibiotic therapy in almost 92% of cases. BSIs occurred after 27 days of hospitalization on average. The main routes of entry were urinary (30%, on indwelling catheters for 2/3 of cases) and cutaneous (17%, catheter-related in almost 80% of cases). Pa was found in 16/49 investigations, representing 34 positive samples, including 54% of sink traps, 23% of water and 20% of tap aerators. An epidemiological link was established between environmental and clinical strains only for 8 patients representing 15% of nosocomial BSIs. ConclusionThe hospital environment usually considered as the main source of Pa healthcare-associated infections was identified as responsible of nosocomial BSIs for only 15% of patients. Since the implementation of water and hospital environment management, one can hypothesize that Pa has become a community-acquired pathogen with a nosocomial expression in infection.

Environmental Vibrio cholerae Strains Harboring Cholera Toxin and Vibrio Pathogenicity Island 1, Nigeria, 2008-2015.

Analysis of clinical and environmental Vibrio cholerae O1 strains obtained during 2008-2015 in Nigeria showed that lineages Afr9 and Afr12 carrying cholera toxin and Vibrio pathogenicity island 1 can be isolated from water. Our findings raise concerns about the role of the environment in maintenance and emergence of cholera outbreaks in Nigeria.

Unveiling environmental transmission risks: comparative analysis of azole resistance in Aspergillus fumigatus clinical and environmental isolates from Yunnan, China.

Azole resistance in Aspergillus fumigatus poses a significant clinical challenge globally. Our previous epidemiological analysis revealed a remarkably high frequency (~80%) of azole-resistant A. fumigatus in Yunnan's greenhouse environments, prompting increased local and regional research for targeted control strategies. In this study, we analyzed 94 clinical A. fumigatus isolates from Yunnan, comparing their susceptibility profiles and genotypic characteristics with environmental strains previously isolated. While the overall frequency of azole resistance in clinical isolates was lower than that in environmental samples, a significant prevalence of cross-resistance, with varying resistance patterns based on minimum inhibitory concentration (MIC) levels was observed, which exceeded rates in other regions of China. Specific mutation combinations in the cyp51A gene were linked to elevated MIC values in clinical and/or environmental samples, while some resistant strains with wild-type cyp51A remain unexplained, indicating a need for further investigation into their resistance mechanisms. The differences in unique genetic elements and the distinct genetic differentiation observed between clinical and environmental isolates can be attributed to Yunnan's unique geomorphology and potential genotype importation from other provinces and abroad. Extensive allele exchanges and sharing contributed to the selection of azole-resistant clinical isolates, suggesting a common environmental origin, and the transmission routes of local drug-resistant strains cannot be excluded. These findings emphasize the imperative for regional and targeted surveillance to monitor resistance trends and guide effective antifungal therapy, and management strategies to mitigate invasive aspergillosis risk in this region.IMPORTANCEAzole resistance in Aspergillus fumigatus is a major global health concern, with particularly high rates (~80%) observed in Yunnan's greenhouse environments. This study compares azole resistance in 94 clinical isolates from Yunnan with environmental strains, revealing lower clinical resistance but significant cross-resistance and distinct resistance patterns. Specific mutations in the cyp51A gene were associated with elevated minimum inhibitory concentration values, though some resistant strains had wild-type cyp51A, highlighting the need for further research. The unique genetic profiles and potential external genotype influences in Yunnan emphasize the need for targeted regional surveillance. Effective monitoring and control strategies are essential to manage and mitigate the risk of invasive aspergillosis.

Diversity of Clostridioides difficile PCR ribotypes isolated from freshwater sediments depends on the isolation method.

Clostridioides difficile is an intestinal pathogen of humans and animals. In community-associated infections, the environment is suggested to play a significant role in overall transmission routes. Although the prevalence of C. difficile in freshwater and soil has been widely studied, little is known about its presence in sediments. In this study, we tested 15 sediment samples collected from various freshwater sources. C. difficile was isolated from all sampled sites, yielding a total of 171 strains grouped into 26 ribotypes, with 001/072 and 014/020 being the most prevalent. Genome sequencing of 37 isolates from 17 PCR ribotypes confirmed the presence of highly related strains in the geographically distant and unlinked water samples. Eight divergent PCR ribotypes from clades C-II and C-III were found in six samples. In each sample, the unbound fraction (supernatant after sediment wash) and bound fraction (sonicated sediment sample) were subjected to enrichment. Sonication was only slightly better than washing in terms of sample positivity (14 positive samples with sonication and 11 with washing). However, sonication substantially increased the diversity of the PCR ribotypes obtained (23 in sonicated samples vs nine in washed samples). In conclusion, sediments are a rich source for investigating the diversity of environmental C. difficile, including isolates from divergent lineages. Selection of the isolation method can significantly impact the diversity of captured PCR ribotypes.IMPORTANCEClostridioides difficile, a pathogenic bacterium that can cause intestinal infections in humans and animals, thrives in the gut but also disperses widely through spores found in the environment. Clinical and environmental strains often overlap with common PCR ribotypes, which are consistently isolated worldwide. Environmental studies have mostly focused on water and soil, but sediments have been very poorly studied. In this study, we investigated the presence of C. difficile in various freshwater sediments and evaluated the effectiveness of two different isolation approaches on positivity rates and strain diversity. C. difficile was found to be highly prevalent in sediments, with an isolation rate of 100%. Sonication proved to be more effective than simple washing for capturing a greater diversity of PCR ribotypes. Overall, this study underscores the widespread presence of C. difficile in freshwater sediments and emphasizes the importance of continued surveillance and monitoring to understand its ecology and transmission dynamics.

Whole genome sequence analysis of multi-drug resistant and biofilm-forming Staphylococcus haemolyticus isolated from bovine milk

BackgroundMilk is an excellent growth medium for microorganisms due to its nutritive composition. Microorganisms have been implicated in bovine mastitis (BM) in dairy cows as well as causing infections in animals and humans. Despite extensive endeavours to manage BM, this condition continues to persist as the most prevalent and economically burdensome problem affecting dairy cattle on a global scale. Non-aureus staphylococci (NAS) species such as Staphylococcus haemolyticus, S. epidermidis, and S. xylosus are currently the predominant microbiological agents identified as the main cause of subclinical udder infections and are also considered opportunistic pathogens in cases of clinical mastitis in dairy cows. Therefore, it is crucial to elucidate the genetic profile of these species. The primary objective of this study was to characterise three phenotypically determined multidrug-resistant NAS environmental strains (NWU MKU1, NWU MKU2, and NWU MKS3) obtained from dairy cows milk via whole-genome sequencing.ResultsThe results confirmed that the three isolates were S. haemolyticus with genome sizes of 2.44, 2.56, and 2.56 Mb and a G + C content of 32.8%. The genomes contained an array of antibiotic resistance genes that may potentially confer resistance to a range of antibiotic classes, such as macrolides, fluoroquinolones, aminoglycosides, cephalosporins, tetracyclines, peptides, and phenicol. Furthermore, all the genomes carried virulence genes, which are responsible for several functions, such as adhesion, enzyme and toxin production. The genomes of these organisms contained signatures encoding mobile genetic elements such as prophages and insertion sequences.ConclusionThese findings indicate there is a need for diligent monitoring with improved management practices and quality control strategies on farms to safeguard milk production systems and human health.

Clavulanic Acid Overproduction: A Review of Environmental Conditions, Metabolic Fluxes, and Strain Engineering in Streptomyces clavuligerus

Clavulanic acid is a potent β-lactamase inhibitor produced by Streptomyces clavuligerus, widely used in combination with β-lactam antibiotics to combat antimicrobial resistance. This systematic review analyzes the most successful methodologies for clavulanic acid overproduction, focusing on the highest yields reported in bench-scale and bioreactor-scale fermentations. Studies have demonstrated that glycerol is the preferred carbon source for clavulanic acid production over other sources like starch and dextrins. The optimization of feeding strategies, especially in fed-batch operations, has improved glycerol utilization and extended the clavulanic acid production phase. Organic nitrogen sources, particularly soybean protein isolates and amino acid supplements such as L-arginine, L-threonine, and L-glutamate, have been proven effective at increasing CA yields both in batch and fed-batch cultures, especially when balanced with appropriate carbon sources. Strain engineering approaches, including mutagenesis and targeted genetic modifications, have allowed for the obtainment of overproducer S. clavuligerus strains. Specifically, engineering efforts that overexpress key regulatory genes such as ccaR and claR, or that disrupt competing pathways, redirect the metabolic flux towards CA biosynthesis, leading to high clavulanic acid titers. The fed-batch operation at the bioreactor scale emerges as the most feasible alternative for prolonged clavulanic acid production with both wild-type and mutant strains, allowing for the attainment of high titers during cultivations.

Intragenomic conflicts with plasmids and chromosomal mobile genetic elements drive the evolution of natural transformation within species.

Natural transformation is the only mechanism of genetic exchange controlled by the recipient bacteria. We quantified its rates in 786 clinical strains of the human pathogens Legionella pneumophila (Lp) and 496 clinical and environmental strains of Acinetobacter baumannii (Ab). The analysis of transformation rates in the light of phylogeny revealed they evolve by a mixture of frequent small changes and a few large quick jumps across 6 orders of magnitude. In standard conditions close to half of the strains of Lp and a more than a third in Ab are below the detection limit and thus presumably non-transformable. Ab environmental strains tend to have higher transformation rates than the clinical ones. Transitions to non-transformability were frequent and usually recent, suggesting that they are deleterious and subsequently purged by natural selection. Accordingly, we find that transformation decreases genetic linkage in both species, which might accelerate adaptation. Intragenomic conflicts with chromosomal mobile genetic elements (MGEs) and plasmids could explain these transitions and a GWAS confirmed systematic negative associations between transformation and MGEs: plasmids and other conjugative elements in Lp, prophages in Ab, and transposable elements in both. In accordance with the hypothesis of modulation of transformation rates by genetic conflicts, transformable strains have fewer MGEs in both species and some MGEs inactivate genes implicated in the transformation with heterologous DNA (in Ab). Innate defense systems against MGEs are associated with lower transformation rates, especially restriction-modification systems. In contrast, CRISPR-Cas systems are associated with higher transformation rates suggesting that adaptive defense systems may facilitate cell protection from MGEs while preserving genetic exchanges by natural transformation. Ab and Lp have different lifestyles, gene repertoires, and population structure. Nevertheless, they exhibit similar trends in terms of variation of transformation rates and its determinants, suggesting that genetic conflicts could drive the evolution of natural transformation in many bacteria.

Comprehensive Review of Microbial Inoculants: Agricultural Applications, Technology Trends in Patents, and Regulatory Frameworks

Agriculture is essential for nutrition and the global economy, becoming increasingly important due to population growth and higher food demand. This situation boosts interest in creating bioproducts that enhance productivity sustainably while reducing environmental issues and strain on natural resources. Bioinoculants are important innovations that use beneficial microorganisms to boost crop growth and resilience. They enhance the interaction between soil and plants by solubilizing essential nutrients and producing phytohormones. This not only boosts agricultural productivity but also promotes environmentally sustainable practices by decreasing reliance on chemical fertilizers. Considering the relevance of this subject to advances in agro-industrial biotechnology, this review analyzes recent studies and patent advances on the production and use of bioinoculants, as well as their integration into agricultural practices and plant development. It also explores the dynamics of production and downstream processes on an industrial scale, regulations in different countries, and growing market demands, which is an important feature of this review. Furthermore, future perspectives for the application of bioinoculants in agro-industrial biotechnology are discussed, emphasizing the critical role that these biological agents play in advancing agricultural sustainability.

Prevalence, Characterization, and Epidemiological Relationships between ESBL and Carbapenemase-Producing Escherichia coli, Klebsiella pneumoniae, and Acinetobacter spp. Isolated from Humans and the Kitchen Environment of Two Greek Hospitals.

Extended-spectrum-β-lactamase (ESBL) and carbapenemase-producing Enterobacterales and Acinetobacter spp. pose significant challenges as nosocomial pathogens, demonstrating resistance against various antimicrobials. Their presence in food suggests that hospital kitchens could serve as antibiotic resistance reservoirs leading to patients' infection. The aim of this study was to assess the prevalence and characteristics of β-lactam-resistant strains of Escherichia coli, Klebsiella pneumoniae, and Acinetobacter spp. isolated from the kitchen environment and from the staff of two Greek hospitals. Strains were recovered after selective isolation with β-lactams and were identified with MALDI-TOF MS. Antimicrobial susceptibility and presence of common β-lactamase genes were evaluated. Protein profiles were examined to analyze potential relationships of the strain with those from hospital patients. E. coli strains were further categorized into phylogenetic groups. The overall prevalence in the kitchen environment was 4.5%, 1.5%, and 15.0% for E. coli, K. pneumoniae, and Acinetobacter spp., respectively, whereas the prevalence of Acinetobacter spp. in human skin was 4.0%. Almost all strains were multidrug-resistant. All E. coli strains were ESBL producers and belonged to phylogroups A and B1. All K. pneumoniae and seven Acinetobacter strains were carbapenemase-producers. A protein profile analysis showed relatedness between chicken and kitchen environment strains, as well as between kitchen environment and patient strains originated either from the same or from different hospitals. The results suggest that hospital kitchens may act as important pathogen hotspots contributing to the circulation of resistant strains in the hospital environment.

Genetic diversity and potential transmission of Escherichia albertii in a poultry breeding rural village.

Escherichia albertii is an emerging foodborne pathogen causing diarrhea. Though various animals, especially poultry, serve as reservoirs, the transmission of E. albertii among reservoirs and the risk to humans remain unclear. This study investigated an E. albertii infected infant with poultry exposure and collected samples from contact persons, poultries, and environment to better understand the transmission dynamics of E. albertii. One E. albertii isolate from contact person, seven isolates from poultries, and six isolates from environment were recovered, respectively. Whole genome sequencing analysis showed that eight strains derived from poultry or environment and classified as ST4633, shared great similarity (cgSNP ≤ 20). However, the patient-derived strain ESA311 had a cgSNP difference of 1165 with human strain ESA339, and differed from poultry and environmental strains (cgSNP range 2417 to 14997), suggesting a distant relatedness. Whole genome phylogeny showed several human-derived E. albertii strains were clustered with those from animal origins. Our results suggested that family-breeding poultry constituted a possible reservoir of E. albertii, with the environment acting as a crucial vector for the spread of these bacteria, posing a risk to humans. Further poultry surveillance is needed to elucidate public health risks associated with E. albertii infection.

Unravelling Virulence Activities of Hospital Isolated Acinetobacter baumannii: Exploring The Prospective Application of Aspirin as an Antivirulence Agent

Acinetobacter baumannii infections pose a global public health threat due to the increasing resistance to various antimicrobial agents. This study reports the virulence characteristics of A. baumannii strains isolated from patients at Hospital Canselor Tuanku Muhriz UKM (HCTM) and explores the potential of aspirin as an antivirulence agent. Fourteen A. baumannii isolates from various infection sites exhibited resistance to at least two antibiotics. Among them, 43% (n=6) displayed high motility, correlating with the site of isolation. Additionally, 58% (n=7) formed strong biofilms, 36% (n=5) secreted proteases and 36% (n=5) resisted oxidative stress. Notably, isolates Ab_H4 and Ab_H10 displayed the highest virulence, warranting further investigation. Molecular analysis using polymerase chain reaction (PCR) showed that both Ab_H4 and Ab_H10 possessed the bap and katG genes. Although both strains were capable of secreting proteases, only Ab_H4 possessed the cpaA gene, suggesting the involvement of other genes in protease secretion in Ab_H10. Despite high motility, no pilT gene was detected in any isolates. Treatment with sub-inhibitory concentrations of aspirin (3.25 mg/ml) restored susceptibility to previously resistant antibiotics, disrupted biofilm formation and reduced proteases and catalases secretion. However, no significant impact on bacterial motility was observed. Interestingly, sub-inhibitory concentrations of aspirin induced biofilm formation in the environmental strain control (Ab_UKMCC), which was significantly reduced upon exposure to the MIC. These findings highlight the high virulence capabilities of several strains isolated from HCTM and show the potential of aspirin as an antivirulence agent, offering valuable insights for combating A. baumannii infections.