Integrating MALDI-TOF Mass Spectrometry with Machine Learning Techniques for Rapid Antimicrobial Resistance Screening of Foodborne Bacterial Pathogens.

Although MALDI-TOF mass spectrometry (MS) is considered as the gold standard for rapid and cost-effective identification of microorganisms in routine laboratory practices, its capability for antimicrobial resistance (AMR) detection has received limited focus. Nevertheless, recent studies explored the predictive performance of MALDI-TOF MS for detecting AMR in clinical pathogens when machine learning techniques are applied. This chapter describes a routine MALDI-TOF MS workflow for the rapid screening of AMR in foodborne pathogens, with Campylobacter spp. as a study model.

Campylobacter Diversity Along the Farm-to-Fork Continuum of Pastured Poultry Flocks in the Southeastern United States.

INTRODUCTION: Consumer demand for pasture raised, antibiotic-free poultry products has led to an increase in pastured poultry operations within the United States. Given the level of environmental interaction and the potential increase in exposure to foodborne pathogens in these settings, a greater understanding of the prevalence and diversity of Campylobacter populations inherent within pastured poultry flocks is needed. METHODS: To achieve this, 40 pastured poultry flocks from nine farms were sampled using a farm-to-fork strategy, and Campylobacter was isolated and characterised from preharvest (faeces, soil) through postharvest (caeca, whole carcass rinse) to the final product the consumer would purchase (whole carcass rinse). RESULTS: Campylobacter was isolated from 872 of 1820 samples, showing an overall prevalence of 47.91%. The caeca showed the highest (p < 0.05) Campylobacter load (4.64 log10 CFU/mL) and prevalence (95.5%), while the final product whole carcass rinses had the lowest (p < 0.05) Campylobacter load (0.32 log10 CFU/mL) and prevalence (15.45%), suggesting that the Campylobacter load in the caeca may not be indicative of the Campylobacter load on the final product. Of the 872 positive samples, 337 Campylobacter isolates were selected for further characterisation. Campylobacter jejuni and Campylobacter coli comprised 74.18% (250/337) and 21.95% (74/337) of the selected isolates respectively. While the Campylobacter isolates displayed resistance to several antibiotics, the most common resistance for both C. jejuni and C. coli was against tetracycline (55.86% and 70.31% respectively). Multidrug resistance phenotypes (≥ 3 antibiotic classes) were relatively low for both C. jejuni (2.80%) and C. coli (9.45%). CONCLUSIONS: Campylobacter load, prevalence and diversity were more affected by farm location than by the type of sample from which the Campylobacter was isolated. Overall, these results indicated a need for farm-specific Campylobacter mitigation strategies to ensure the safety of these increasingly in-demand poultry products.

Spinal Epidural Abscess Caused by Campylobacter jejuni Without Gastrointestinal Symptoms.

Campylobacter jejuni (C. jejuni) is a gram-negative bacterium known to cause gastroenteritis with fever, abdominal pain, and bloody diarrhea. Although Campylobacter bacteremia is reported in patients with gastroenteritis, localized abscess formation, particularly spinal epidural abscess (SEA), is extremely rare and can easily be missed. Herein, we report a case of a 54-year-old immunocompromised female presenting with severe back pain without gastrointestinal symptoms, who was ultimately diagnosed with an L5/S1 SEA due to C.jejuni, requiring laminectomy and drainage. As far as we know, this is the second reported case of SEA due to C. jejuni without any preceding gastrointestinal symptoms. This case highlights the critical importance of performing a contrasted MRI for the early and accurate diagnosis of SEA.

Campylobacter-Associated Myocarditis in a 17-Year-Old Male.

Chest pain is a common presenting complaint in adolescent patients. Myocarditis is an important and potentially serious etiology of chest pain for clinicians who care for these patients to recognize. Myocarditis is commonly virally mediated, while extra-intestinal cardiac manifestations of bacterial enteritis, such as Campylobacter infections,are rare. Awareness of this uncommon, but potentially life-threatening pathophysiology is important for clinicians to understand.  In our case, a 17-year-old male presented with chest discomfort, chest pain on inspiration, headache, myalgias, vomiting, and diarrhea. He denied recent viral illnesses or immunizations. He lived in rural Ohio, swam recently in a freshwater lake, and had eaten home-prepared deer meat. His father had diarrhea as well. Presenting vital signs were within normal limits for age. The patient was obese (BMI 48.5), with an otherwise normal physical exam, including a thorough cardiopulmonary assessment. Laboratory workup revealed leukocytosis (16.1 x 109/L) and elevated high-sensitivity troponin (15,857 ng/L, >22,000 ng/L three hours later, ref range <20). Gastrointestinal polymerase chain reaction (PCR) panel detected Campylobacter spp., and stool culture was positive for Campylobacter jejuni. ECG, echocardiography, chest X-ray, and CT angiography were normal. Cardiac MRI revealed an increased T2 signal consistent with myocarditis. The patient was treated with non-steroidal anti-inflammatory drugs (NSAIDs) and azithromycin and had complete resolution in symptoms. He was exercise-restricted for six months.  Myocarditis is a potentially fatal pathology, representing a significant cause of sudden death in young adults. Myocarditis can present with a broad spectrum of signs and symptoms as well as variable clinical severity. Bacterial causes of myocarditis are uncommon, with Campylobacter among the least common. Campylobacter gastroenteritis, however, is quite common worldwide. Extra-intestinal and cardiac manifestations are rare; thus, it is important to maintain a high index of suspicion. Due in part to its rarity, treatment for Campylobacter-associated myocarditis is not well established. Treatment for myocarditis, regardless of etiology, is largely supportive in nature. Campylobacter-directed antibiotics, such as azithromycin, have been used successfully in adolescents with Campylobacter-associated myocarditis. Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently used for symptom control, though their use remains controversial. Activity restriction is recommended for six months to reduce the risk of sudden cardiac death.  Myocarditis is an important cause of sudden death in young adults and is a rare extra-intestinal manifestation of Campylobacter bacterial gastroenteritis. Pediatric and adult providers should be aware of this presentation and its pathophysiology. They should also utilize a multi-modal workup, aggressive supportive care, appropriate subspecialty consultation, and appropriate antibiotics for patients with diarrheal illness and a high clinical suspicion for extra-intestinal involvement, such as myocarditis.

Campylobacter spp. in men who have sex with men: A systematic review.

OBJECTIVES: Campylobacter spp. has been reported to be a sexually transmissible enteric infection in men who have sex with men (MSM) since the 1980s causing an acute severe diarrhoeal illness and rarely an acute demyelinating polyneuropathy (Guillain-Barré syndrome). The aim of this review was to explore the factors seen in MSM with Campylobacter spp. METHODS: We conducted a systematic review following PRISMA guidelines by searching 7 bibliographical databases in August 2024 for manuscripts in English. Initial screening was conducted by a primary author and then two authors conducted independent full-text reviews to determine the final eligible manuscripts. We only included manuscripts which explored factors seen in MSM with Campylobacter spp.. Two authors independently used the Joanna Briggs Institute critical appraisal tools to assess risk for bias. This review was registered with PROSPERO (CRD42023464803). RESULTS: 25 manuscripts met the inclusion criteria that included 265 MSM with Campylobacter spp.. This review has highlighted demographic factors (living with HIV, living in urban MSM districts, HIV negative MSM using HIV-PrEP), biological factors (antimicrobial resistant Campylobacter spp., having a concurrent or previous sexually transmitted infection [Neisseria gonorrhoeae, Chlamydia trachomatis, Herpes simplex virus, Hepatitis C, Mpox] current/previous enteric infection including non-pathogenic parasites [Shigella spp., Giardia duodenalis, Cryptosporidium, Entamoeba histolytica, Salmonella spp., Entamoeba hartmanii, Entamoeba coli, Endolimax nana, Iodamoeba butchlii]) and behavioural factors (condomless receptive anal sex, oral-anal sex, oral genital sex, multiple/new sexual partners, using sex on premises venues and the internet to meet sexual partners) seen in MSM with Campylobacter spp. CONCLUSION: This review has highlighted some important demographic, biological and behavioural risk factors seen in MSM with Campylobacter spp.. These data can be used to inform future public health interventions and clinical guidelines.

Carbapenem resistant Campylobacter jejuni bacteremia in a Bruton's X-linked agammaglobulinemia patient.

Immunocompromised patients are prone to recurrent Campylobacter infections. We report a case of recurrent multi-drug resistant Campylobactor jejuni bloodstream infections in a Bruton's X-linked agammaglobulinemia patient with prolonged ertapenem treatment. The isolate from the fifth recurrence developed carbapenem resistance, which is associated with mutations in a porin gene porA, and promoter changes and duplication of chromosomal blaOXA-61 gene. Combination therapy using cefepime and doxycycline (later switched to moxifloxacin) cleared the infection.

Effects of cinnamon, rosemary and oregano on growth performance, blood biochemistry, liver enzyme activities, excreta microbiota and ileal morphology of Campylobacter jejuni-challenged broiler chickens.

BACKGROUND: Phytogenic additives would be helpful to mitigate the detrimental impact of Campylobacter jejuni on broiler chickens. OBJECTIVE: The experiment aimed to assess the effects of cinnamon, rosemary and oregano powder on physiological responses of broiler chickens challenged with C. jejuni from 0 to 42 days of age. METHODS: A total of 192 one-day-old male broiler chickens were divided into 6 treatment groups. The treatments included: negative control (NC; basal diet without additives and no C. jejuni challenge), positive control (PC; basal diet with C. jejuni challenge), PC with cinnamon, rosemary or oregano powder (3 g/kg each), and PC with Erythromycin (55 mg/kg). Except for the NC group, all chicks were orally challenged with 2 × 108 CFU/mL C. jejuni daily from days 21-25. Feed intake, body weight gain (BWG), feed conversion ratio (FCR), energy efficiency ratio (EER) and protein efficiency ratio (PER) were assessed during the rearing period (0-42 days). On day 42 of age, fresh excreta samples were collected from each pen to determine apparent dry matter digestibility and excreta microbiota. In addition, at the end of the experiment, blood samples were collected to evaluate blood profile and liver enzyme activities. RESULTS: C. jejuni challenge (PC treatment) decreased BWG, EER and PER, while increasing FCR of broiler chickens (p < 0.05), whereas rosemary, oregano and Erythromycin improved these performance parameters akin to NC. PC diet showed negative effect in ileal morphology, alleviated by additives except cinnamon (p < 0.05). Dietary additives successfully reduced Campylobacter levels and increased Lactobacilli counts in the PC. Rosemary and oregano lowered plasma total cholesterol (p < 0.05). Alanine aminotransferase elevation by C. jejuni challenge in the PC group was prevented by rosemary, oregano and Erythromycin (p < 0.05). CONCLUSIONS: Oregano and rosemary alleviate the impact of C. jejuni challenge.

Campylobacteriosis: A rising threat in foodborne illnesses.

Campylobacteriosis is a foodborne illness that is contracted by eating contaminated food, particularly animal products like meat from diseased animals or corpses tainted with harmful germs. The epidemiology of campylobacteriosis varies significantly between low-, middle-, and high-income countries. Campylobacter has a complicated and poorly known survival strategy for getting past host barriers and causing sickness in humans. The adaptability of Campylobacter to unfavorable environments and the host's immune system seems to be one of the most crucial elements of intestinal colonization. A Campylobacter infection may result in fever, nausea, vomiting, and mild to severe bloody diarrhea in humans. Effective and rapid diagnosis of Campylobacter species infections in animal hosts is essential for both individual treatment and disease management at the farm level. According to the most recent meta-analysis research, the main risk factor for campylobacteriosis is travel, which is followed by eating undercooked chicken, being exposed to the environment, and coming into close contact with livestock. Campylobacter jejuni, and occasionally Campylobacter coli, are the primary causes of Campylobacter gastroenteritis, the most significant Campylobacter infection in humans for public health. The best antibiotic medications for eradicating and decreasing Campylobacter in feces are erythromycin, clarithromycin, or azithromycin. The best strategy to reduce the number of human infections caused by Campylobacter is to restrict the amount of contamination of the poultry flock and its products, even if the majority of infections are contracted through handling or ingestion of chicken.

Increased Motility in Campylobacter jejuni and Changes in Its Virulence, Fitness, and Morphology Following Protein Expression on Ribosomes with Altered RsmA Methylation.

Infection with Campylobacter jejuni is the major cause of human gastroenteritis in the United States and Europe, leading to debilitating autoimmune sequelae in many cases. While considerable progress has been made in detailing the infectious cycle of C. jejuni, a full understanding of the molecular mechanisms responsible for virulence remains to be elucidated. Here, we apply a novel approach by modulating protein expression on the pathogen's ribosomes by inactivating a highly conserved rRNA methyltransferase. Loss of the RsmA methyltransferase results in a more motile strain with greater adhesive and cell-invasive properties. These phenotypical effects correlate with enhanced expression of specific proteins related to flagellar formation and function, together with enzymes involved in cell wall/membrane and amino acid synthesis. Despite the enhancement of certain virulent traits, the null strain grows poorly on minimal media and is rapidly out-competed by the wild-type strain. Complementation with an active copy of the rsmA gene rescues most of the traits changed in the mutant. However, the complemented strain overexpresses rsmA and displays new flaws, including loss of the spiral cell shape, which is distinctive for C. jejuni. Proteins linked with altered virulence and morphology are identified here by mass spectrometry proteomic analyses of the strains.

Campylobacter infection of young children in Colombia and its impact on the gastrointestinal environment.

Campylobacter infections are a leading cause of bacterial-derived gastroenteritis worldwide with particularly profound impacts on pediatric patients in low- and middle-income countries. It remains unclear how Campylobacter impacts these hosts, though it is becoming increasingly evident that it is a multifactorial process that depends on the host immune response, the gastrointestinal microbiota, various bacterial factors, and host nutritional status. Since these factors likely vary between adult and pediatric patients in different regions of the world, it is important that studies define these attributes in well-characterized clinical cohorts in diverse settings. In this study, we analyzed the fecal microbiota and the metabolomic and micronutrient profiles of asymptomatic and symptomatic pediatric patients in Colombia who were either infected or uninfected with Campylobacter during a case-controlled study on acute diarrheal disease. Here, we report that the microbiome of Campylobacter-infected children only changed in their abundance of Campylobacter spp. despite the inclusion of children with or without diarrhea. In addition to increased Campylobacter, computational models were used to identify fecal metabolites that were associated with Campylobacter infection and found that glucose-6-phosphate and homovanillic acid were the strongest predictors of infection in these pediatric patients, which suggests that colonocyte metabolism is impacted during infection. Despite changes to the fecal metabolome, the concentrations of intestinal minerals and trace elements were not significantly impacted by Campylobacter infection but were elevated in uninfected children with diarrhea.IMPORTANCEGastrointestinal infection with pathogenic Campylobacter species has long been recognized as a significant cause of human morbidity. Recently, it has been observed that pediatric populations in low- and middle-income countries are uniquely impacted by these organisms in that infected children can be persistently colonized, develop enteric dysfunction, and exhibit reduced development and growth. While the association of Campylobacter species with these long-term effects continues to emerge, the impact of infection on the gastrointestinal environment of these children remains uncharacterized. To address this knowledge gap, our group leveraged clinical samples collected during a previous study on gastrointestinal infections in pediatric patients to examine the fecal microbiota, metabolome, and micronutrient profiles of those infected with Campylobacter species and found that the metabolome was impacted in a way that suggests gastrointestinal cell metabolism is affected during infection, which is some of the first data indicating how gastrointestinal health in these patients may be affected.

A Decade of Antimicrobial Resistance in Human and Animal Campylobacter spp. Isolates.

Objectives: Campylobacter spp. remain a leading cause of bacterial gastroenteritis worldwide, with resistance to antibiotics posing significant challenges to treatment and public health. This study examines profiles in antimicrobial resistance (AMR) for Campylobacter isolates from human and animal sources over the past decade. Methods: We conducted a comprehensive review of resistance data from studies spanning ten years, analyzing profiles in resistance to key antibiotics, ciprofloxacin (CIP), tetracycline (TET), erythromycin (ERY), chloramphenicol (CHL), and gentamicin (GEN). Data were collated from various regions to assess global and regional patterns of resistance. Results: The analysis reveals a concerning trend of increasing resistance patterns, particularly to CIP and TET, across multiple regions. While resistance to CHL and GEN remains relatively low, the high prevalence of CIP resistance has significantly compromised treatment options for campylobacteriosis. Discrepancies in resistance patterns were observed between human and animal isolates, with variations across different continents and countries. Notably, resistance to ERY and CHL showed regional variability, reflecting potential differences in antimicrobial usage and management practices. Conclusions: The findings underscore the ongoing challenge of AMR in Campylobacter, highlighting the need for continued surveillance and research. The rising resistance prevalence, coupled with discrepancies in resistance patterns between human and animal isolates, emphasize the importance of a One Health approach to address AMR. Enhanced monitoring, novel treatment strategies, and global cooperation are crucial for mitigating the impact of resistance and ensuring the effective management of Campylobacter-related infections.

Whole-genome comparison using complete genomes from Campylobacter fetus strains revealed single nucleotide polymorphisms on non-genomic islands for subspecies differentiation.

Introduction: Bovine Genital Campylobacteriosis (BGC), caused by Campylobacter fetus subsp. venerealis, is a sexually transmitted bacterium that significantly impacts cattle reproductive performance. However, current detection methods lack consistency and reliability due to the close genetic similarity between C. fetus subsp. venerealis and C. fetus subsp. fetus. Therefore, this study aimed to utilize complete genome analysis to distinguish genetic features between C. fetus subsp. venerealis and other subspecies, thereby enhancing BGC detection for routine screening and epidemiological studies. Methods and results: This study reported the complete genomes of four C. fetus subsp. fetus and five C. fetus subsp. venerealis, sequenced using long-read sequencing technologies. Comparative whole-genome analyses (n = 25) were conducted, incorporating an additional 16 complete C. fetus genomes from the NCBI database, to investigate the genomic differences between these two closely related C. fetus subspecies. Pan-genomic analyses revealed a core genome consisting of 1,561 genes and an accessory pangenome of 1,064 genes between the two C. fetus subspecies. However, no unique predicted genes were identified in either subspecies. Nonetheless, whole-genome single nucleotide polymorphisms (SNPs) analysis identified 289 SNPs unique to one or the C. fetus subspecies. After the removal of SNPs located on putative genomic islands, recombination sites, and those causing synonymous amino acid changes, the remaining 184 SNPs were functionally annotated. Candidate SNPs that were annotated with the KEGG "Peptidoglycan Biosynthesis" pathway were recruited for further analysis due to their potential association with the glycine intolerance characteristic of C. fetus subsp. venerealis and its biovar variant. Verification with 58 annotated C. fetus genomes, both complete and incomplete, from RefSeq, successfully classified these seven SNPs into two groups, aligning with their phenotypic identification as CFF (Campylobacter fetus subsp. fetus) or CFV/CFVi (Campylobacter fetus subsp. venerealis and its biovar variant). Furthermore, we demonstrated the application of mraY SNPs for detecting C. fetus subspecies using a quantitative PCR assay. Discussion: Our results highlighted the high genetic stability of C. fetus subspecies. Nevertheless, Campylobacter fetus subsp. venerealis and its biovar variants encoded common SNPs in genes related to glycine intolerance, which differentiates them from C. fetus subsp. fetus. This discovery highlights the potential of employing a multiple-SNP assay for the precise differentiation of C. fetus subspecies.

Novel Drug-like HsrA Inhibitors Exhibit Potent Narrow-Spectrum Antimicrobial Activities against Helicobacter pylori.

Helicobacter pylori infection constitutes a silent pandemic of global concern. In the last decades, the alarming increase in multidrug resistance evolved by this pathogen has led to a marked drop in the eradication rates of traditional therapies worldwide. By using a high-throughput screening strategy, in combination with in vitro DNA binding assays and antibacterial activity testing, we identified a battery of novel drug-like HsrA inhibitors with MIC values ranging from 0.031 to 4 mg/L against several antibiotic-resistant strains of H. pylori, and minor effects against both Gram-negative and Gram-positive species of human microbiota. The most potent anti-H. pylori candidate demonstrated a high therapeutic index, an additive effect in combination with metronidazole and clarithromycin as well as a strong antimicrobial action against Campylobacter jejuni, another clinically relevant pathogen of phylum Campylobacterota. Transcriptomic analysis suggests that the in vivo inhibition of HsrA triggers lethal global disturbances in H. pylori physiology including the arrest of protein biosynthesis, malfunction of respiratory chain, detriment in ATP generation, and oxidative stress. The novel drug-like HsrA inhibitors described here constitute valuable candidates to a new family of narrow-spectrum antibiotics that allow overcoming the current resistome, protecting from dysbiosis, and increasing therapeutic options for novel personalized treatments against H. pylori.

Genetic Diversity, Virulence, and Antibiotic Resistance Determinants of Campylobacter jejuni Isolates in Romania.

The emergence of antibiotic-resistant Campylobacter jejuni, a leading cause of gastroenteritis worldwide, presents a significant public health challenge requiring vigilant surveillance and disease control. This study aimed to characterize C. jejuni strains isolated in Romania from 2017 to 2020, focusing on genetic diversity, virulence, and antibiotic resistance determinants. The isolates underwent phenotypical testing, PCR, and antibiotic resistance assessment using the Kirby-Bauer disc diffusion method for ciprofloxacin, erythromycin, and tetracycline. Genetic analysis identified resistance and virulence genes, point mutations, and performed sequence typing (7-gene MLST) to determine genetic relatedness. Results indicated substitutions at position 86 in the amino acid sequence or position 257 in the nucleotide sequence of the gyrA gene in 47 fluoroquinolone-resistant isolates. Additionally, mutations in the rRNA 23S gene at positions 2074 and 2075, associated with macrolide resistance, were found in 12 of the 66 isolates. Allelic profiles generated 38 sequence types (STs), including three new STs not present in the reference database. The sequence data analysis revealed a genetically diverse C. jejuni population with a weak clonal structure. This study provides crucial insights into the genetic diversity and antibiotic resistance of C. jejuni strains in Romania, highlighting the need for ongoing surveillance and control measures.

First Case Report of Mycotic Abdominal Aortic Aneurysm Caused by Campylobacter fetus in Serbia.

BACKGROUND: Due to its distinct vascular tropism, Campylobacter fetus is recognized as a significant cause of severe systemic infections, especially in immunocompromised individuals, while it is rarely reported as a cause of gastrointestinal infections. METHODS: A rare case of mycotic abdominal aortic aneurysm associated with Campylobacter fetus detected on the aneurysm wall itself was described. RESULTS: A 68-year-old male was admitted to the hospital due to severe abdominal pain. The patient was afebrile, hemodynamically stable with elevated C-reactive protein levels. A physical examination revealed a palpable, pulsatile, tender mass located in the periumbilical region. Ultrasonography and multi-slice computer tomography angiography (MSCTA) identified an infrarenal abdominal aortic aneurysm with a maximum diameter of 6.5 cm, showing suspicious signs of dissection. Aneurysmectomy with Dacron tube graft interposition was performed. Although the blood cultures remained negative, the culture of the aneurysmal wall grew Campylobacter fetus, enabling early diagnosis and targeted antibiotic therapy. The patient was treated with meropenem for two weeks, followed by amoxicillin-clavulanate for another two weeks after hospital discharge. CONCLUSIONS: Campylobacter fetus associated with abdominal aortic aneurysms represents a life-threatening condition, posing a significant challenge in vascular surgery. Due to the lack of clear guidelines on antibiotic susceptibility testing and the treatment of infections associated with this pathogen, enhanced surveillance of Campylobacter fetus is necessary in both human and veterinary medicine.

Campylobacter fetus subspecies specific PCR assays inferred from comparative genomic analysis for accurate subspecies identification.

Bovine Genital Campylobacteriosis (BGC) is caused by Campylobacter fetus subsp. venerealis and is a notifiable disease to the WOAH (World Organisation for Animal Health). For an effective BGC control program, the reliable differentiation of Campylobacter fetus subsp. venerealis (Cfv) from the closely related Campylobacter fetus subsp. fetus (Cff) is required. However, the available molecular C. fetus subspecies identification assays lack sensitivity and specificity to differentiate C. fetus isolates based on their phenotypic or genotypic differences. Furthermore, the current biochemical subspecies identification is not fully congruent with the genomic differentiation of C. fetus strains. In this study, the genome sequences of 41C. fetus strains with well identified subspecies, were analyzed with the large-scale BLAST score ratio (LS-BSR) pipeline to identify Cff and Cfv specific sequences. With this analysis, the asd gene encoding an aspartate-semialdehyde dehydrogenase was identified, which contained a 6-bp Cff-specific sequence, and this 6-bp sequence was absent in the asd gene of Cfv strains. This sequence was used for the development of PCR assays to differentiate Cff and Cfv strains. The C. fetus subspecies identification of the developed asd PCR assays was in full congruence with the genomic classification of strains and are recommended for molecular identification of C. fetus subspecies in BGC control programs. The asd PCR can be assessed on sequenced genomes using a web interface containing the Cfvcatch tool, which includes placement of the tested genome in a phylogenetic tree with reference C. fetus genomes to distinguish the two subspecies and to detect antimicrobial resistance genes.

Detection of Gastrointestinal Pathogens with Zoonotic Potential in Horses Used in Free-Riding Activities during a Countrywide Study in Greece.

The objectives of this study were (a) to detect zoonotic gastrointestinal pathogens in faecal samples of horses using the FilmArray® GI Panel and (b) to identify variables potentially associated with their presence. Faecal samples collected from 224 horses obtained during a countrywide study in Greece were tested by means of the BioFire® FilmArray® Gastrointestinal (GI) Panel, which uses multiplex-PCR technology for the detection of 22 pathogens. Gastrointestinal pathogens were detected in the faecal samples obtained from 97 horses (43.3%). Zoonotic pathogens were detected more frequently in samples from horses in courtyard housing (56.0%) than in samples from horses in other housing types (39.7%) (p = 0.040). The most frequently detected zoonotic pathogens were enteropathogenic Escherichia coli (19.2% of horses) and Shiga-like toxin-producing E. coli stx1/stx2 (13.8%). During multivariable analysis, two variables emerged as significant predictors for the outcome 'detection of at least one zoonotic pathogen in the faecal sample from an animal': (a) the decreasing age of horses (p = 0.0001) and (b) the presence of livestock at the same premises as the horses (p = 0.013). As a significant predictor for the outcome 'detection of two zoonotic pathogens concurrently in the faecal sample from an animal', only the season of sampling of animals (autumn) emerged as significant in the multivariable analysis (p = 0.049). The results indicated a diversity of gastrointestinal pathogens with zoonotic potential in horses and provided evidence for predictors for the infections; also, they can serve to inform horse owners and handlers regarding the possible risk of transmission of pathogens with zoonotic potential. In addition, our findings highlight the importance of continuous surveillance for zoonotic pathogens in domestic animals.

Effect of low concentrations of lactic acid and temperature on the expression of adhesion, invasion, and toxin-encoding genes of Campylobacter jejuni from poultry.

Background and Objectives: The consumption of contaminated poultry meat is considered as a significant route of campylobacteriosis transmission. Lactic acid is a disinfectant agent with bactericidal effects on Campylobacter spp. The purpose of this study was to assess the low concentrations of lactic acid effect and different temperatures on the transcriptomic responses of Campylobacter jejuni (C. jejuni) adhesion and virulence-associated genes including peb4, ciaB, cdtA, cdtB, and cdtC. Materials and Methods: The samples were incubated at 10°C and 22°C for 48 h upon exposure to 30% and 60% lactic acid. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of lactic acid was also determined. Then, gene expression was assessed using real-time polymerase chain reaction (RT-PCR). Results: Lactic acid had lower MIC and MBC levels at lower temperature. The utilization of both levels of lactic acid significantly reduced the expression of peb4, ciaB, cdtB, and cdtC genes over 48 h of incubation at 22°C. However, no significant difference was found in the expression of the cdtA gene between 10 and 22°C at 30% lactic acid. Conclusion: These results highlight the potential of low-concentration lactic acid in the downregulation of adhesion and virulence-associated genes as well as reduction of C. jejuni pathogenicity.

Diagnosis of Campylobacter spp. Isolates and Their Antimicrobial Susceptibility Patterns.

This study aimed to reveal antibiotic resistance patterns and molecular characterization of quinolone resistance Campylobacter isolates in patients with diarrhea. Campylobacter spp. isolated from 35.33% of the total samples, most of which were from male patients aged 3 months to 10 years. Identifying isolates at the species level made in MALDI-TOF MS, 82.4% were C. jejuni, and 17.6% were C. coli. Respectively 94% (47/50), 58% (29/50), and 2% (1/50) resistance rates were determined for ciprofloxacin, tetracycline, and erythromycin. While C. jejuni isolates were more resistant to ciprofloxacin and tetracycline than C. coli, they showed no resistance to erythromycin. Quinolone resistance determining region (QRDR) were evaluated by mismatch amplification mutation test and all quinolone resistant strains gave positive results. One of the seven silent mutations identified was specific to this study, and two other novel mutations were also identified. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-024-01199-5.

Draft genomes of multidrug-resistant Campylobacter jejuni and Campylobacter coli strains from Brazil representing novel sequence types.

Whole-genome sequencing identified three previously unidentified multilocus sequence types of Campylobacter jejuni (ST-12332) and Campylobacter coli (ST-12333 and ST-12663), harboring resistance genes for multiple antimicrobial classes. The sources of isolation highlight the circulation of resistance strains within animals and humans, emphasizing the need for preventive measures.