Proteus mirabilis from community-acquired urinary tract infections (UTI-CA) shares genetic similarity and virulence factors with isolates from chicken, beef and pork meat

Clonal relationship, virulence genes, and antimicrobial resistance of Morganella morganii isolated from community-acquired infections and hospitalized patients: a neglected opportunistic pathogen

Morganella morganii is a bacterium belonging to the normal intestinal microbiota and the environment; however, in immunocompromised individuals, this bacterium can become an opportunistic pathogen, causing a series of diseases, both in hospitals and in the community, being urinary tract infections more prevalent. Therefore, the objective of this study was to evaluate the prevalence, virulence profile, and resistance to antimicrobials and the clonal relationship of isolates of urinary tract infections (UTI) caused by M. morganii, both in the hospital environment and in the community of the municipality of Londrina-PR, in southern Brazil, in order to better understand the mechanisms for the establishment of the disease caused by this bacterium. Our study showed that M. morganii presents a variety of virulence factors in the studied isolates. Hospital strains showed a higher prevalence for the virulence genes zapA, iutA, and fimH, while community strains showed a higher prevalence for the ireA and iutA genes. Hospital isolates showed greater resistance compared to community isolates, as well as a higher prevalence of multidrug-resistant (MDR) and extended-spectrum beta lactamase (ESBL)-producing isolates. Several M. morganii isolates from both sources showed high genetic similarity. The most prevalent plasmid incompatibility groups detected were FIB and I1, regardless of the isolation source. Thus, M. morganii isolates can accumulate virulence factors and antimicrobial resistance, making them a neglected opportunistic pathogen.

Recent Records on Bacterial Opportunistic Infections via the Dietary Route

This narrative review was aimed at identifying the opportunistic bacterial pathogens that can be transmitted by contaminated food and represent a current threat for patients particularly susceptible to infections because of underlying conditions or predisposing factors. The analysis was focused on recent case or outbreak reports and systematic reviews published in the years 2019 to 2023 and resulted in sorting 24 bacterial groups comprising the genera or species able to cause a variety of systemic or invasive infections if ingested with food or drinking water. These included both bacteria known to cause mild infections in immunocompetent persons and bacteria considered to be innocuous, which are used in food fermentation or as probiotics. No recent cases of infections transmitted through dietary routes were reported for the critical nosocomial pathogens widely found in food products, primarily Acinetobacter baumannii and Klebsiella pneumoniae. However, the very first sources of their introduction into the clinical environment still need to be established. In many instances, risky dietary habits, such as eating raw fish, seafood, raw meat, unpasteurized milk, and their derived products or the lack of control in fermentation processes, has led to the reported illnesses, pointing out the necessity to improve the hygiene of production and consumer awareness of the risks.

Resistance and Virulence Surveillance in Escherichia coli Isolated from Commercial Meat Samples: A One Health Approach

Escherichia coli is a key indicator of food hygiene, and its monitoring in meat samples points to the potential presence of antimicrobial-resistant strains capable of causing infections in humans, encompassing resistance profiles categorized as serious threats by the Centers for Disease Control and Prevention (CDC), such as Extended-Spectrum Beta-Lactamase (ESBL)-a problem with consequences for animal, human, and environmental health. The objective of the present work was to isolate and characterize ESBL-producing E. coli strains from poultry, pork, and beef meat samples, with a characterization of their virulence and antimicrobial resistance profiles. A total of 450 meat samples (150 chicken, 150 beef, and 150 pork) were obtained from supermarkets and subsequently cultured in medium supplemented with cefotaxime. The isolated colonies were characterized biochemically, followed by antibiogram testing using the disk diffusion technique. Further classification involved biofilm formation and the presence of antimicrobial resistance genes (blaCTX-M, AmpC-type, mcr-1, and fosA3), and virulence genes (eaeA, st, bfpA, lt, stx1, stx2, aggR, iss, ompT, hlyF, iutA, iroN, fyuA, cvaC, and hylA). Statistical analysis was performed via the likelihood-ratio test. In total, 168 strains were obtained, with 73% originating from chicken, 22% from pork, and 17% from beef samples. Notably, strains exhibited greater resistance to tetracycline (51%), ciprofloxacin (46%), and fosfomycin (38%), apart from β-lactams. The detection of antimicrobial resistance in food-isolated strains is noteworthy, underscoring the significance of antimicrobial resistance as a global concern. More than 90% of the strains were biofilm producers, and strains carrying many ExPEC genes were more likely to be biofilm formers (OR 2.42), which increases the problem since the microorganisms have a greater chance of environment persistence and genetic exchange. Regarding molecular characterization, bovine samples showed a higher prevalence of blaCTX-M-1 (OR 6.52), while chicken strains were more likely to carry the fosA3 gene (OR 2.43, CI 1.17-5.05) and presented between 6 to 8 ExPEC genes (OR 2.5, CI 1.33-5.01) compared to other meat samples. Concerning diarrheagenic E. coli genes, two strains harbored eae. It is important to highlight these strains, as they exhibited both biofilm-forming capacities and multidrug resistance (MDR), potentially enabling colonization in diverse environments and causing infections. In conclusion, this study underscores the presence of β-lactamase-producing E. coli strains, mainly in poultry samples, compared to beef and pork samples. Furthermore, all meat sample strains exhibited many virulence-associated extraintestinal genes, with some strains harboring diarrheagenic E. coli (DEC) genes.

Prevalence of Antimicrobial Resistance and Clonal Relationship in ESBL/AmpC-Producing Proteus mirabilis Isolated from Meat Products and Community-Acquired Urinary Tract Infection (UTI-CA) in Southern Brazil

The present study aimed to evaluate the prevalence of antimicrobial resistance and clonal relationships in Proteus mirabilis isolated from chicken meat, beef, pork, and community-acquired urinary tract infections (UTI-CA). Chicken meat isolates showed the highest multidrug resistance (MDR), followed by those from pork and UTI-CA, whereas beef had relatively few MDR strains. All sources had strains that carried bla_CTX-M-65, whereas bla_CTX-M-2 and bla_CMY-2 were only detected in chicken meat and UTI-CA isolates. This indicates that chicken meat should be considered an important risk factor for the spread of P. mirabilis carrying ESBL and AmpC. Furthermore, ESBL/AmpC producing strains were resistant to a greater number of antimicrobials and possessed more resistance genes than non-producing strains. In addition, the antimicrobial resistance genes qnrD, aac(6')-Ib-cr, sul1, sul2, fosA3, cmlA, and floR were also found. Molecular typing showed a genetic similarity between chicken meat and UTI-CA isolates, including some strains with 100% similarity, indicating that chicken can be a source of P. mirabilis causing UTI-CA. It was concluded that meat, especially chicken meat, can be an important source of dissemination of multidrug-resistant P. mirabilis in the community.

Detection of the dominant pathogens in diarrheal calves of Ningxia, China in 2021-2022

Introduction

Calf diarrhea is a complex disease that has long been an unsolved problem in the cattle industry. Ningxia is at the forefront of China in the scale of cattle breeding, and calf diarrhea gravely restricts the development of Ningxia's cattle industry.

Methods

From July 2021 to May 2022, we collected diarrhea stool samples from calves aged 1-103 days from 23 farms in five cities in Ningxia, and performed PCR using specific primers for 15 major reported pathogens of calf diarrhea, including bacteria, viruses, and parasites. The effect of different seasons on the occurrence of diarrhea in calves was explored, the respective epidemic pathogens in different seasons were screened, and more detailed epidemiological investigations were carried out in Yinchuan and Wuzhong. In addition, we analyzed the relationship between different ages, river distributions and pathogen prevalence.

Results

Eventually, 10 pathogens were detected, of which 9 pathogens were pathogenic and 1 pathogen was non-pathogenic. The pathogens with the highest detection rate were Cryptosporidium (50.46%), Bovine rotavirus (BRV) (23.18%), Escherichia coli (E. coli) K99 (20.00%), and Bovine coronavirus (BCoV) (11.82%). The remaining pathogens such as Coccidia (6.90%), Bovine Astrovirus (BoAstV) (5.46%), Bovine Torovirus (BToV) (4.09%), and Bovine Kobuvirus (BKoV) (3.18%) primarily existed in the form of mixed infection.

Discussion

The analysis showed that different cities in Ningxia have different pathogens responsible for diarrhea, with Cryptosporidium and BRV being the most important pathogens responsible for diarrhea in calves in all cities. Control measures against those pathogens should be enforced to effectively prevent diarrhea in calves in China.

Characterization of Escherichia coli and other bacteria isolated from condemned broilers at a Danish abattoir

Meat inspection is important to ensure food safety and protect public health. Visual inspection of slaughtered carcasses for pathological changes should be supported by bacteriological analysis to determine whether the entire carcass or parts of it should be condemned. The aim of this study was to determine the bacterial species present in different sample types from condemned broiler carcasses. Furthermore, we investigated the genetic characteristics, zoonotic potential, and relatedness of Escherichia coli, the predominant bacterial species isolated from the carcasses. A total of 400 broiler carcasses condemned because of cellulitis (100), scratches (100), hepatitis (100), and healthy control carcasses (100) were selected. Samples of meat, pathological lesion, and bone marrow of each carcass were obtained for microbial analysis. From the analyzed samples, 469 bacterial isolates were recovered with E. coli accounting for 45.8%, followed by Aeromonas spp. (27.9%), in particular A. veronii. The highest rate of bacterial isolation was observed in carcasses condemned with cellulitis, whereas carcasses with hepatitis had the lowest rate of bacterial isolation. Forty-four E. coli isolates originating from different sample types were selected for whole genome sequencing. A clonal relationship was shown between E. coli from different sample types of the same carcass condemned with cellulitis and scratches. A major clade of E. coli was found in carcasses condemned with cellulitis with isolates containing mdf(A), tet(A), and bla TEM-1B genes that confer resistance to macrolides, tetracycline, and ampicillin, respectively. E. coli in this clade all belonged to ST117 and clustered with E. coli isolates previously collected from dead chickens and carcasses condemned due to cellulitis in Denmark, Finland, and the United Kingdom. Bacterial evaluation results of carcasses condemned with cellulitis, scratches (moderate to severe skin lesion), and acute hepatitis confirmed the need for total condemnation of carcasses with these pathological findings. A similar evaluation should be done for carcasses affected with chronic hepatitis, and minor scratches lesions.

Detection of Carbapenem Resistance of Proteus mirabilis Strains Isolated from Foxes, Raccoons and Minks in China

Proteus mirabilis, an opportunistic pathogen, is found to be an emerging threat to both animals and humans for a variety of infections. However, the characteristics of P. mirabilis infections from foxes, raccoons and minks remain unclear. In this context, we identified the antibiotic resistance genes and virulence genes of P. mirabilis isolates from foxes, raccoons and minks in China. Most isolates showed resistance to florfenicol (90.57%), trimethoprim-sulfamethoxazole (73.58%), and imipenem (71.70%). A total of 73.58% of isolates were resistant to antibiotics from at least three or more classes, and were categorized as multi-drug resistant. A total of 33.33% of the isolates were resistant to antibiotics from seven classes. The most prevalent resistant were sul1 (94.34%), followed by floR, blaTEM, aac(6’)Ib-cr and blaOXA-1 with the detection rate of 88.68%, 83.02%, 71.70% and 60.38%, respectively. Among the 51 P. mirabilis isolates that were resistant to beta-lactam antibiotics, all isolates carried at least one beta-lactam gene. In addition, blaNDM and blaOXA-24 genes were firstly reported in carbapenem-resistant P. mirabilis isolates from foxes, raccoons and minks. All isolates exhibited the virulence genes ureC, zapA, pmfA, atfA and mrpA. P. mirabilis isolates carrying all detected 10 virulence genes from different animal species showed different lethal abilities in a G. mellonella larvae model. More importantly, the profiles of antibiotic resistance genes of isolates from fur animals and the environment were generally similar, and phylogenetic analysis showed that the P. mirabilis isolates from farm environment samples may have close relatedness with that from animals.