Percorrer por autor "Vieira-Pinto, Madalena"
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- Antibiotic resistance among gastrointestinal bacteria in broilers: a review focused on Enterococcus spp. and Escherichia coliPublication . Ribeiro, Jessica; Silva, Vanessa; Monteiro, Andreia; Vieira-Pinto, Madalena; Igrejas, Gilberto; Reis, Filipa S.; Barros, Lillian; Poeta, PatríciaSimple Summary Chicken meat has become one of the most consumed meats worldwide, and antibiotics have been used to ensure high levels of production. However, antibiotic usage in animal production has contributed to the development of antibiotic-resistant bacteria, largely among intestinal microbiota. Enterococcus spp. and Escherichia coli are frequently found in the gastrointestinal tract of chickens, and the presence of resistant strains has been revealed by several studies. Enterococcus spp. isolated from broilers have shown resistance to at least seven classes of antibiotics, while E. coli have shown resistance to at least four. Furthermore, some clonal lineages, such as ST16, ST194, and ST195 in Enterococcus spp. and ST117 in E. coli, have been identified in broilers and humans. These data suggest that bacteria can be transmitted through the consumption of contaminated animal-source food, direct contact with animals, or environmental exposure. Therefore, the main goal of this review was to highlight the existing literature on the gastrointestinal microbiota in broilers and antibiotic-resistant Enterococcus spp. and E. coli of broiler origin. Chickens can acquire bacteria at different stages, and bacterial diversity can occur due to production practices, diet, and environment. The changes in consumer trends have led to increased animal production, and chicken meat is one of the most consumed meats. To ensure high levels of production, antimicrobials have been used in livestock for therapeutic purposes, disease prevention, and growth promotion, contributing to the development of antimicrobial resistance across the resident microbiota. Enterococcus spp. and Escherichia coli are normal inhabitants of the gastrointestinal microbiota of chickens that can develop strains capable of causing a wide range of diseases, i.e., opportunistic pathogens. Enterococcus spp. isolated from broilers have shown resistance to at least seven classes of antibiotics, while E. coli have shown resistance to at least four. Furthermore, some clonal lineages, such as ST16, ST194, and ST195 in Enterococcus spp. and ST117 in E. coli, have been identified in humans and animals. These data suggest that consuming contaminated animal-source food, direct contact with animals, or environmental exposure can lead to the transmission of antimicrobial-resistant bacteria. Therefore, this review focused on Enterococcus spp. and E. coli from the broiler industry to better understand how antibiotic-resistant strains have emerged, which antibiotic-resistant genes are most common, what clonal lineages are shared between broilers and humans, and their impact through a One Health perspective.
- Genomic Analysis of Antibiotic Resistance and Virulence Profiles in Escherichia coli Linked to Sternal Bursitis in Chickens: A One Health PerspectivePublication . Ribeiro, Jessica; Silva, Vanessa; Freitas, Catarina; Pinto, Pedro; Vieira-Pinto, Madalena; Batista, Rita; Nunes, Alexandra; Gomes, João Paulo; Pereira, José Eduardo; Igrejas, Gilberto; Barros, Lillian; Heleno, Sandrina A.; Reis, Filipa S.; Poeta, PatríciaSternal bursitis is an underexplored lesion in poultry, often overlooked in microbiological diagnostics. In this study, we characterized 36 Escherichia coli isolates recovered from sternal bursitis in broiler chickens, combining phenotypic antimicrobial susceptibility testing, PCR-based screening, and whole genome sequencing (WGS). The genetic analysis revealed a diverse population spanning 15 sequence types, including ST155, ST201, and ST58. Resistance to tetracycline and ciprofloxacin was common, and several isolates carried genes encoding beta-lactamases, including blaTEM-1B. Chromosomal mutations associated with quinolone and fosfomycin resistance (e.g., gyrA p.S83L, glpT_E448K) were also identified. WGS revealed a high number of virulence-associated genes per isolate (58-96), notably those linked to adhesion (fim, ecp clusters), secretion systems (T6SS), and iron acquisition (ent, fep, fes), suggesting strong pathogenic potential. Many isolates harbored virulence markers typical of ExPEC/APEC, such as iss, ompT, and traT, even in the absence of multidrug resistance. Our findings suggest that E. coli from sternal bursitis may act as reservoirs of resistance and virulence traits relevant to animal and public health. This highlights the need for including such lesions in genomic surveillance programs and reinforces the importance of integrated One Health approaches.
- Genomic and phenotypic characterization of Enterococcus faecalis from broiler sternal bursitis: antimicrobial resistance and one health risksPublication . Ribeiro, Jessica; Silva, Vanessa; Pinto, Pedro; Vieira-Pinto, Madalena; Batista, Rita; Nunes, Alexandra; Gomes, João Paulo; Igrejas, Gilberto; Barros, Lillian; Heleno, Sandrina A.; Reis, Filipa S.; Poeta, PatríciaEnterococcus spp. are opportunistic bacteria capable of acquiring antimicrobial resistance and virulence traits, facilitating their adaptation to multiple ecological niches. Sternal bursitis, a condition affecting poultry welfare and carcass quality, remains poorly characterized from a microbiological perspective. This study provides the first genomic and phenotypic characterization of Enterococcus isolates from bursitis lesions in broilers, aiming to assess their antimicrobial resistance profiles, virulence determinants, and genetic diversity within a One Health framework. A total of 44 Enterococcus isolates were recovered from 48 sternal bursitis lesions, all identified as E. faecalis. Resistance was common for tetracycline (70.5%) and erythromycin (27.3%), while all isolates remained susceptible to critically important antimicrobials, including vancomycin and linezolid. Whole genome sequencing revealed a genetically diverse population, comprising multiple sequence types, plasmid replicons, and virulence gene profiles, including determinants for adhesion, biofilm formation, capsule synthesis, and extracellular proteases. Ionophore resistance genes (narA, narB) were also detected in several lineages. The coexistence of antimicrobial resistance and virulence determinants, often linked to mobile genetic elements, highlights the potential of lesion-associated with E. faecalis to act as reservoirs of relevant genes with zoonotic implications. Overall, this work highlights the diverse and ecological role of Enterococcus in extraintestinal poultry infections, reinforcing the need for continued genomic surveillance to promote animal health, food safety, and antimicrobial stewardship.
- Scrapie at abattoir: monitoring, control, and differential diagnosis of wasting conditions during meat inspectionPublication . Esteves, Alexandra; Vieira-Pinto, Madalena; Quintas, Helder; Orge, Leonor; Gama, Adelina; Alves, Anabela; Seixas, Fernanda; Pires, Isabel; Pinto, Maria de Lurdes; Mendonça, Ana Paula; Lima, Carla; Machado, Carla Neves; Silva, João Carlos; Tavares, Paula; Silva, Filipe; Bastos, Estela; Pereira, Jorge; Gonçalves-Anjo, Nuno; Carvalho, Paulo; Sargo, Roberto; Matos, Ana; Figueira, Luís; Pires, Maria dos AnjosWasting disease in small ruminants is frequently detected at slaughterhouses. The wasting disorder is manifested by the deterioration of the nutritional and physiological state of the animal indicated by thinness, emaciation, and cachexia. Evidence of emaciation and cachexia, alone, are pathological conditions leading to carcass condemnation during an inspection. Several diseases are associated with a wasting condition, including scrapie, pseudotuberculosis, tuberculosis, paratuberculosis, Maedi Visna, and tumor diseases. On the other hand, parasitic diseases, nutrition disorders, exposure or ingestion of toxins, metabolic conditions, inadequate nutrition due to poor teeth, or poor alimentary diet are conditions contributing to poor body condition. Classical and atypical scrapie is naturally occurring transmissible spongiform encephalopathies in small ruminants. The etiological agent for each one is prions. However, each of these scrapie types is epidemiologically, pathologically, and biochemically different. Though atypical scrapie occurs at low incidence, it is consistently prevalent in the small ruminant population. Hence, it is advisable to include differential diagnosis of this disease, from other possibilities, as a cause of wasting conditions detected during meat inspection at the abattoir. This manuscript is a review of the measures in force at the abattoir for scrapie control, focusing on the differential diagnosis of gross lesions related to wasting conditions detected in small ruminants during meat inspection.