Search Results (263)

Background/Objectives: Campylobacteriosis in human populations is an ongoing issue in both developed and developing countries. Poultry production is recognized as a reservoir for antimicrobial resistance and main source of human Campylobacter infection. Methods: In this study, sixty-five Campylobacter isolates were cultured from fecal samples collected from 17 flocks of broiler chickens in Alberta, Canada over two years (2015–2016). Susceptibility assays and PCR assays were performed to characterize resistance phenotypes and resistance genes. Conjugation assays were used to examine the mobility of AMR phenotypes. Results: Campylobacter jejuni was the predominant species recovered during both years of sampling. There were no Campylobacter coli isolates found in 2015; however, approximately 33% (8/24) of isolates collected in 2016 were Campylobacter coli. The two most frequent antimicrobial resistance patterns in C. jejuni collected in 2015 were tetracycline (39%) and azithromycin/clindamycin/erythromycin/telithromycin resistance (29%). One isolate collected in 2015 has resistance pattern ciprofloxacin/nalidixic acid/tetracycline. The tetO gene was detected in all tetracycline resistant isolates from 2015. The cmeB gene was detected in all species isolates with resistance to azithromycin/clindamycin/erythromycin/telithromycin, and from two isolates with tetracycline resistance. Alignment of the nucleotide sequences of the cmeB gene from C. jejuni isolates with different resistance patterns revealed several single nucleotide polymorphisms. A variety of multi-drug resistance patterns were observed through conjugation experiments. Conclusions: These data suggest that poultry production may serve as a potential reservoir for and source of transmission of multi-drug resistant Campylobacter jejuni and supports the need for continued surveillance. Full article

The intersection of microbial food safety and antimicrobial resistance (AMR) represents a mounting global threat with profound implications for public health, food safety, and sustainable development. This review explores the complex pathways through which foodborne pathogens—such as Salmonella spp., Escherichia coli (E. coli), Listeria monocytogenes (L. monocytogenes), and Campylobacter spp.—acquire and disseminate resistance within human, animal, and environmental ecosystems. Emphasizing a One Health framework, we examine the drivers of AMR across sectors, including the misuse of antibiotics in agriculture, aquaculture, and clinical settings, and assess the role of environmental reservoirs in sustaining and amplifying resistance genes. We further discuss the evolution of surveillance systems, regulatory policies, and antimicrobial stewardship programs (ASPs) designed to mitigate resistance across the food chain. Innovations in next-generation sequencing, metagenomics, and targeted therapeutics such as bacteriophage therapy, antimicrobial peptides (AMPs), and CRISPR-based interventions offer promising alternatives to conventional antibiotics. However, the translation of these advances into practice remains uneven, particularly in low- and middle-income countries (LMICs) facing significant barriers to diagnostic access, laboratory capacity, and equitable treatment availability. Our analysis underscores the urgent need for integrated, cross-sectoral action—anchored in science, policy, and education—to curb the global spread of AMR. Strengthening surveillance, investing in research, promoting responsible antimicrobial use, and fostering global collaboration are essential to preserving the efficacy of existing treatments and ensuring the microbiological safety of food systems worldwide. Full article

Background: Campylobacter causes gastroenteritis worldwide with increasing antimicrobial resistance. Furazolidone (FZD) shows potential in resource-poor areas but needs further study. We aimed to assess the in vitro susceptibility of Campylobacter spp. to FZD, ciprofloxacin (CIP), and erythromycin (ERY) in a high-risk pediatric cohort and to evaluate the clinical relevance of resistance patterns using inhibitory quotient (IQ) pharmacodynamics. Methods: A two-phase prospective study (2012–2013, 2014–2015) was conducted at a tertiary pediatric hospital in Lima, Peru. Stool samples from children ≤24 months were cultured on selective media, with Campylobacter isolates identified via conventional bacteriological methods. Antimicrobial susceptibility was determined using Kirby–Bauer disk diffusion and regression-derived minimum inhibitory concentrations (MICs). IQ analysis correlated inhibition zones with therapeutic outcomes. Results: Among 194 Campylobacter isolates (C. jejuni: 28%; C. coli: 72%), resistance to CIP declined from 97.7% (2012–2013) to 83% (2014–2015), while ERY resistance rose from 2.3% to 9.4% (p= 0.002). No FZD resistance was observed, with mean inhibition zones of 52 ± 8 mm (2012–2013) and 43 ± 10.5 mm (2014–2015). MICs for FZD were predominantly <0.125 μg/mL, and all susceptible isolates demonstrated favorable IQ outcomes. Multidrug resistance (≥2 drugs) increased to 6.2% (2014–2015), though all MDR strains retained FZD susceptibility. CLSI and EUCAST breakpoints showed concordance for ERY (p = 0.724) but discordance for CIP (p = 0.022 vs. 0.008). Conclusions: FZD exhibits sustained in vitro efficacy against Campylobacter spp., even among MDR strains, contrasting with escalating fluoroquinolone and macrolide resistance. Full article

Campylobacter jejuni and Campylobacter coli are the two main campylobacter species that cause foodborne campylobacteriosis. Recent studies have reported that Campylobacter spp. are prone to developing resistance to antibiotics commonly used for their treatment, with many C. coli strains identified as multidrug-resistant. This study presents the results of the whole-genome sequencing analysis of the multidrug-resistant C. coli strain BCT3 isolated in Greece from a stool specimen of a pediatric patient presenting with diarrhea. The strain was isolated using selective culture media and, based on antimicrobial susceptibility tests, was found to be resistant to ciprofloxacin, tetracycline, erythromycin, azithromycin, clarithromycin, and doxycycline. To further characterize it, we performed whole-genome sequencing, which identified strain BCT3 as C. coli. Moreover, multilocus sequence typing assigned the BCT3 to the sequence type (ST) 872, belonging to clonal complex ST-828. The presence of multiple virulence genes revealed its pathogenic potential. The detection of antimicrobial resistance genes and mutated alleles was indicative of its resistance to fluoroquinolones, macrolides, and tetracyclines, supporting the observed phenotype. To our knowledge, this is the first reported clinical case of such a multidrug-resistant C. coli strain in Greece. Full article

Invasive bacterial gastrointestinal infections represent a substantial clinical burden worldwide, contributing to significant morbidity and, in severe cases, mortality. The causative bacterial agents of these infections include Shigella spp., enteroinvasive Escherichia coli, Salmonella spp., Campylobacter jejuni, Yersinia enterocolitica, and Listeria monocytogenes. Given the growing challenges of therapy failures and rising antibiotic resistance, there is still an unmet need to identify novel, effective, and safe compounds exhibiting antimicrobial, anti-inflammatory, and immunomodulatory activities. In the present review, we aimed to compile current data regarding three alkaloids—berberine, sanguinarine, and cheleritrin—which hold significant promise in treating bacterial invasive gastrointestinal diseases. Our review extended beyond the direct antimicrobial properties of these compounds against pathogens capable of breaching the intestinal epithelial barrier. We also presented their modulatory effects on intestinal barrier integrity and their influence on the composition and function of the resident gut microbiota, thereby highlighting their potential indirect role in attenuating pathogen invasion and disease progression. Thus, our review presents alkaloids as potential preparations that potentiate the activity of classic anti-infective drugs, as well as substances that, by affecting the microbiome and intestinal mucosa, could be used for inflammatory bowel diseases. Full article

Campylobacter jejuni is a leading cause of bacterial gastroenteritis worldwide which usually presents as mild, and self-limiting disease in immunocompetent individuals. However, in immunocompromised patients, such as those with common variable immunodeficiency, C. jejuni can cause severe recurrent infections requiring antibiotic treatment. Our study reports a case of a 37-year-old male patient with CVID, who had multiple episodes of C. jejuni intestinal infections over a 3.5-year period. A total of 27 stool samples were collected and analyzed between December 2020 and July 2024 during acute febrile diarrheal episodes, with C. jejuni isolated in 15 samples. Antimicrobial susceptibility testing (AST) during the course of the disease revealed three different antimicrobial resistance profiles including multi-drug-resistant phenotype. Whole genome sequencing was performed on three representative isolates, all identified as MLST type 367, ST-257 complex, with minimal genetic divergence, indicating a clonal origin. Genes and point mutations conferring resistance to macrolides, fluoroquinolones, beta-lactams, and tetracycline were identified in different C. jejuni isolates, along with key virulence factors linked to adherence, invasion, motility, and immune evasion. The genetic analysis of macrolide phenotypic resistance revealed different resistance mechanisms. Genotypic and phenotypic analyses of the same C. jejuni clone from single patient, and identified multidrug resistance pattern, present the first documented case of in vivo resistance development of C. jejuni in Croatia. This case highlights the role of prolonged antibiotic pressure in driving resistance evolution and underscores the need for careful antimicrobial stewardship and genomic monitoring in immunocompromised patients. Further research is needed to correlate phenotypic resistance with genetic determinants in Campylobacter spp. Full article

In ovo administration of probiotics has the potential to enable the early colonization of the gut microbiota, providing health benefits from the onset of life. This study aimed to assess the impact of in ovo probiotic inoculation combined with early posthatch feeding on intestinal development and colonization by Campylobacter spp., immune system development, and the final production performance of chickens. On the 18th day of incubation, Bacillus subtilis, Lactobacillus fermentum, Enterococcus faecium, or physiological saline (control) was administered to Ross 308 eggs in ovo, and chicks had immediate access to feed and water upon hatching. On the 7th, 21st, and 35th days after hatching, samples of tissues were taken for histomorphometric analysis. Campylobacter strains in the cecal content were quantitatively evaluated. Probiotic administration had a beneficial effect on the development of the small intestine and increased the number of B cells in the spleen and the number of B and CD4⁺ cells in the cecal tonsils. The in ovo administration of probiotics did not reduce Campylobacter jejuni colonization and even led to increased bacterial loads in some groups by day 35. However, when combined with early feeding, in ovo probiotic administration had a positive impact on the development of the small intestine and peripheral immune organs. Full article

Antibiotics have revolutionized medicine, with (fluoro)quinolones emerging as one of the most impactful classes of antibacterial agents. Since their introduction, four generations of (fluoro)quinolones have been developed, demonstrating a broad spectrum of activity, favourable pharmacokinetics, and clinical efficacy. However, the rise of multidrug-resistant pathogens has posed significant challenges to their continued effectiveness, particularly in healthcare settings. Among the main resistant species, Staphylococcus aureus, particularly methicillin-resistant strains (MRSA), Klebsiella pneumoniae, Enterococcus spp. (E. faecium and E. faecalis), Campylobacter spp., and Acinetobacter baumannii are the most important. This critical literature review provides an updated perspective on (fluoro)quinolones (old and new), encompassing their spectrum of activity, pharmacokinetics, mechanisms of resistance, and the role of antimicrobial stewardship in preserving their utility, to address the growing threat of resistance. Full article

Campylobacter spp. are the causative agents of campylobacteriosis, a major foodborne illness globally, with millions of cases reported annually. These pathogens pose significant risks to both human and animal health. Conventional culture-based diagnostic methods are labor-intensive and time-consuming, underscoring the need for more efficient molecular detection strategies. This study employed a pangenomic analysis to identify novel gene-specific markers for pathogenic Campylobacter species and subspecies, laying the groundwork for their application in diverse diagnostic assays. A curated dataset of 105 high-quality genomes, representing 33 species and 9 subspecies, was analyzed using the Roary ILP Bacterial Annotation Pipeline. The results revealed substantial genomic diversity within the genus, with core gene counts varying across different nucleotide identity thresholds. Ribosomal genes such as rpsL, rpsJ, rpsS, rpmA, rpsK, rpsU, rpsG, rpmH, and rpsZ were consistently identified in the core genome, whereas accessory genes exhibited marked variability. This study uncovered novel and highly specific genetic markers for various Campylobacter species, including petB, clpX, and carB for C. coli; hypothetical proteins for C. jejuni and C. fetus; porA2 for C. lari; and mdtJ for C. upsaliensis. These markers demonstrated a specificity of at least 90% with minimal cross-reactivity with non-target organisms. The findings underscore the genomic heterogeneity within Campylobacter and provide essential genetic targets for the enhanced molecular detection of its pathogenic species, subspecies, and biovars. Full article

Campylobacter spp. is one of the most prevalent causes of zoonotic foodborne infections associated with diarrhea in humans. The growing threat of antibiotic resistance calls for innovative approaches. The antimicrobial lipopeptide brevibacillin produced by Brevibacillus laterosporus and its synthetic analog brevibacillin Thr1 showed promising activity against Salmonella and E. coli. The latter is a 1602.13 Da positively charged (+3) synthetic peptide of 13 residues that showed reduced cytotoxicity (IC₅₀ of 32.2 µg/mL against Caco-2 cells) and hemolytic activity (1.2% hemolysis at 128 µg/mL) compared to the native peptide. It contains an N-terminal L-isoleucic fatty acid chain and four non-proteinogenic amino acids and ends with valinol at its C-terminus. One key structural modification is the substitution of α,β-dehydrobutyric acid with threonine. We investigated the antimicrobial potential of the synthetic brevibacillin Thr1 analog against a collection of 44 clinical Campylobacter spp. that were obtained from two reference laboratories. Susceptibility testing revealed marked resistance to ciprofloxacin, tetracycline, and ampicillin among the strains, with more than half expressing a multidrug-resistant phenotype. The genomes of the 44 strains were sequenced to study the genes responsible for their antimicrobial resistance. Tetracycline resistance was associated with tet(O), ciprofloxacin resistance with mutations in gyrA and regulatory sequences modulating the expression of an efflux system, and aminoglycoside resistance with genes of the aph family. The brevibacillin Thr1 analog was produced by chemical synthesis, and evaluation of its activity against a subset of clinical strains by microdilution revealed minimum inhibitory concentration and minimum bactericidal concentration ranging from 8 µg/mL to 64 µg/mL. The peptide was active against multidrug-resistant isolates with a bactericidal effect. Of note, despite numerous attempts, it proved impossible to select Campylobacter spp. for resistance to the brevibacillin Thr1 analog. These results underline the potential of lipopeptides, notably brevibacillin, as antimicrobial alternatives against antibiotic-resistant Campylobacter bacterial infections. Full article

Background/Objectives: Acute diarrheal illnesses are a major cause of hospital admissions, particularly in immunocompromised patients. Traditional diagnostic methods are slow and often insensitive, delaying treatment. In contrast, PCR panels provide rapid, sensitive detection of multiple pathogens. This study evaluates stool PCR testing in hospitalized adults and its impact on clinical decisions and antimicrobial stewardship. Methods: We conducted a retrospective study at Bistrița County Hospital, Romania (September 2023–September 2024), including 75 adults with acute diarrhea and negative conventional stool tests. PCR testing (VIASURE panels I and II) detected 11 bacteria, 6 viruses, and 5 parasites. Clinical and therapeutic data were analyzed, and logistic regression identified predictors of PCR positivity and adverse outcomes. Results: PCR was positive in 78% of cases, with Campylobacter spp. (57.6%) and Clostridioides difficile (20.3%) being the most common. Bloody diarrhea independently predicted PCR positivity (OR 9.78, p = 0.047). Immunosuppression and end-stage liver disease were linked to worse outcomes. PCR results led to antimicrobial therapy adjustments in 40 patients (p = 0.001), correcting inappropriate antibiotic use in 66% of those receiving empirical treatment. Targeted therapy significantly reduced antimicrobial duration from 7 to 5 days (p = 0.00001). Conclusions: Stool PCR testing enhances pathogen detection, guides targeted therapy, and reduces inappropriate antibiotic use, supporting antimicrobial stewardship and improving outcomes in selected hospitalized patients. Full article

Monitoring Campylobacter and antimicrobial resistance is critical, as its presence in the food chain, particularly in poultry, represents a serious threat to public health. However, despite its significant impact, this bacterium remains largely underestimated and under-surveilled in many countries, including Morocco. The current study aims to understand the occurrence of Campylobacter spp. in different poultry production systems, highlighting the importance of continuously monitoring antimicrobial susceptibility in these bacteria. For this purpose, 300 poultry samples were collected from a slaughterhouse and 254 from traditional markets in the Rabat-Salé-Kénitra region. The research on Campylobacter was performed according to the standard ISO10272-1(2017), and the confirmation of Campylobacter species was carried out using MALDI-TOF mass spectrometry. Additionally, the disk diffusion method was employed to assess antimicrobial susceptibility, and conventional PCR was utilized to detect the presence of the tet(O) gene in tetracycline-resistant strains. Out of 554 samples collected, 159 (28.7%) tested positive for Campylobacter, of which 84% were identified as Campylobacter coli and 16% as Campylobacter jejuni. Moreover, the results revealed a notably higher detection of Campylobacter in traditional markets (41.33%) than in slaughterhouses (19.85%). Additionally, it was more prevalent in chicken samples (35.37%) than in turkey samples (22.02%). Campylobacter resistance to antimicrobials revealed a resistance rate of 99% to ciprofloxacin, 73% to ampicillin, 82% to tetracycline, 29% to erythromycin, and 0% to gentamicin, as well as to the association of amoxicillin and clavulanic acid. Among the strains with a phenotypic resistance profile to tetracycline, 80% carried the tet(O) gene. The results provide an overview of the current state of antibiotic resistance in Campylobacter in Morocco. They underline the urgent need for the prudent use of antimicrobials and may encourage further research into the development of new antimicrobial agents. They also highlight the importance of raising awareness of the risk of carcass contamination Full article

Background and objectives: Acute gastroenteritis (AGE) remains a significant cause of morbidity in children, particularly in low- and middle-income countries. Viral pathogens, including rotavirus (RoV), norovirus (NoV), and adenovirus (HAdV), are among the leading causes of AGE. This study aimed to determine the prevalence of viral, bacterial, and parasitic enteric pathogens associated with AGE among hospitalized children in Northern Jordan. Materials and Methods: A total of 195 stool samples were collected from hospitalized children with AGE during the winter seasons of 2022–2024. Multiplex real-time qPCR assays were performed to detect common pathogens. The prevalence of each pathogen was determined, and co-infections were analyzed. Clinical symptoms, demographic characteristics, and associations between specific pathogens and disease severity were evaluated. Results: Viral pathogens were the predominant cause of AGE, with NoV detected in 53 cases (27.2%; of which 19.0% were NoV GI and 8.2% NoV GII), followed by RoV (24.1%), HAdV (20.0%), HAstV (13.3%), and SaV (12.3%). Co-infections were observed in several cases, particularly among viral infections evoked by RoV, HAdV, and NoV GI. Bacterial and parasitic infections were less prevalent, with Salmonella and Campylobacter spp. detected in 23.1% and 13.8%, respectively. Additionally, Cryptosporidium was identified in two cases (0.5%). Conclusions: Viral pathogens, particularly NoV, RoV, and HAdV, are the leading causes of AGE among hospitalized children in Jordan. Co-infections among viral pathogens were common, whereas bacterial and parasitic infections played a limited role in the disease burden. These findings emphasize the importance of continued surveillance and vaccination efforts, particularly for RoV, to reduce AGE-related hospitalizations in children. Full article

Foodborne diseases (FBDs) represent a significant public health concern, particularly in regions like Central America and the Caribbean (CAC), where surveillance gaps due to a lack of resources, knowledge, and technical abilities hinder control over outbreaks. This review investigates the bacterial pathogens responsible for FBDs, their prevalence, management challenges, and prevention strategies. This systematic review followed PRISMA guidelines, focusing on bacterial FBDs in CAC from 2000 to 2024. PubMed and Google Scholar were used as primary databases, supported by other sources to identify relevant studies. Inclusion criteria encompassed studies focusing on bacterial pathogens, prevalence, risk factors, and surveillance practices. Out of the 509 studies initially identified, 35 met the inclusion criteria. The most prevalent pathogens were Salmonella spp., Escherichia coli, Campylobacter spp., and Aliarcobacter spp., with contamination often associated with poultry, eggs, and vegetables. Key challenges included inadequate surveillance systems, limited resources, and inconsistent reporting practices. A more significant investment in pathogen monitoring, documentation, and education, along with technologies like whole-genome sequencing (WGS), is crucial. Institutional and governmental funding is vital to improve surveillance and strengthen regional risk analysis. Full article

Campylobacter spp. represents one of the most frequently incriminated pathogens in the evolution of foodborne gastroenteritis in humans worldwide. Alongside Salmonella spp., Yersinia spp., Escherichia coli, and Listeria monocytogenes, these pathogens represent a principal threat to public health because they are vehiculated to humans via food products and many of them have developed alarming resistance to different classes of antimicrobials. Thus, the present study aimed to provide scientifically relevant data on the public health risk represented by Campylobacter spp., contamination of chicken carcasses at the slaughterhouse and retail levels, and the antimicrobial resistance of the isolated strains. A total of 130 samples collected from slaughterhouses (n = 40) and retail stores (n = 90) were analyzed using standardized microbiological methods (ISO 10272-1:2017). Of these, the overall prevalence of Campylobacter spp. was 27.7%, with a prevalence at the slaughterhouse level of 32.5% and at the retail level of 25.5%. Following antimicrobial resistance profile determinations using the Kirby–Bauer disc diffusion assay, the isolated strains showed resistance to the following antimicrobials in descending order: ciprofloxacin (41.6%), tetracycline (25.0%), chloramphenicol (16.6%), gentamicin (11.1%), ertapenem (5.6%), and erythromycin (2.8%). The study results confirm that chicken meat may pose a threat to public health and, moreover, that due to the widespread use of antimicrobials, a large number of strains have developed antimicrobial resistance, leading to difficulties in the treatment of various foodborne diseases. Full article