Characterization of an Emerging Enterococcus cecorum Outbreak Causing Severe Systemic Disease with Concurrent Leg Problems in a Broiler Integrator in the Southern United States.

Enterococcus cecorum has been associated mainly with osteomyelitis of the free thoracic vertebra in chickens. However, there are reports of E. cecorum producing septicemic lesions and having tropism for cartilages, resulting in the presentation of femoral head necrosis and synovitis. This paper discusses the presentation of E. cecorum as it relates to an outbreak in one vertical integrator where the main lesions were related to septicemia. Using a convenience sampling method, 100 broiler chicken cases received at the Poultry Research and Diagnostic Laboratory of Mississippi State University from April to December of 2021 were analyzed. The peak in cases was observed from June to August. The average age of broilers was 21 days with a range of 15-31 days. Most of these cases were related to systemic disease and leg problems, with gross lesions including characteristic pericarditis along with perihepatitis, osteomyelitis, and arthritis. In six of the 100 cases, E cecorum was isolated from the free thoracic vertebra, with the remaining being recovered from various other locations including liver, pericardium, hock/joint, femoral head, and bone marrow. Enterococcus cecorum identification was performed by using Vitek matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. These results were then sent to the research-use only SARAMIS database for analysis. Once the spectra of the isolates were imported, the relative and absolute taxonomy were analyzed. Two super spectrums and three clusters by homology were identified. The minimal inhibitory concentrations obtained by antimicrobial sensitivity tests were analyzed using WHONET Microbiology Laboratory Database Software. No isolates were pan-susceptible, 80% of isolates were noted to be resistant to ≥3 classes of antibiotics and, in general, isolates exhibited a high degree of variability when examining antimicrobial resistance patterns.

Reporte de caso- Caracterización de un brote reciente de Enterococcus cecorum causante de una enfermedad sistémica grave simultáneamente con problemas en las patas en un integrador de pollo de engorde en el sur de los Estados Unidos. La bacteria Enterococcus cecorum se ha asociado principalmente con osteomielitis de la vértebra torácica móvil de los pollos. Sin embargo, existen reportes de E. cecorum produciendo lesiones septicémicas y presentando tropismo por los cartílagos, resultando en la presentación de necrosis de la cabeza femoral y sinovitis. Este artículo analiza la presentación de E. cecorum relacionada con un brote en un integrador vertical donde las principales lesiones estaban relacionadas con septicemia. Utilizando un método de muestreo de conveniencia, se analizaron 100 casos de pollos de engorde recibidos en el Laboratorio de Investigación y Diagnóstico Avícolas de la Universidad Estatal de Mississippi de abril a diciembre del 2021. El mayor número de casos se observó de junio a agosto. La edad promedio de los pollos de engorde fue de 21 días con un rango de 15 a 31 días. La mayoría de estos casos estaban relacionados con enfermedad sistémica y problemas en las patas, con lesiones macroscópicas que incluían pericarditis característica junto con perihepatitis, osteomielitis y artritis. En seis de los 100 casos, E cecorum se aisló de la vértebra torácica móvil, y el resto de los casos se recuperó de otros lugares, incluyendo el hígado, el pericardio, articulación del corvejón, la cabeza femoral y la médula ósea. La identificación de E. cecorum se realizó utilizando la plataforma Vitek de espectrometría de masas MALDI-TOF. Posteriormente, estos resultados se enviaron a la base de datos SARAMIS de uso exclusivo para investigación para su análisis. Una vez importados los espectros de los aislados, se analizó la taxonomía relativa y absoluta. Se identificaron dos superespectros y tres grupos mediante homología. Las concentraciones inhibitorias mínimas obtenidas mediante pruebas de sensibilidad antimicrobiana se analizaron utilizando el software de base de datos de laboratorio de microbiología de WHONET. Ningún aislamiento fue pan-susceptible, se observó que el 80% de los aislamientos eran resistentes a tres o más clases de antibióticos y en general, los aislamientos exhibieron un alto grado de variabilidad al examinar los patrones de resistencia a los antimicrobianos.

A Novel Presentation of Clostridium perfringens in Young Broilers.

Necrotic enteritis (NE) is an important intestinal disease of commercial poultry associated with poor performance, high mortality, and significant economic loss. In this case report, a novel presentation of NE is described in young broilers. Initially, affected farms presented with a moderate increase in mortality at or before 19 days of age. Farms experiencing the disease syndrome belonged to two complexes of the same company. However, all farms sourced chicks from the same hatchery. Farm postmortem examinations revealed moderate to severe enteritis of the upper small intestine characterized by multifocal, irregular, plaque-like, mucosal ulcerations. Additionally, thinning of the intestinal wall with consequential distension and ballooning and a necrotic, pseudomembranous layer covering the mucosa were observed in some birds. Clinically affected birds were submitted to the Poultry Research and Diagnostic Laboratory at Mississippi State University for further evaluation. Birds were between 5 and 11 days of age and presented with similar gross lesions. Anaerobic culture was performed, and Clostridium perfringens was isolated from affected intestinal sections. Environmental sampling at the hatchery was also performed to evaluate the presence and load of clostridial organisms. Clostridium perfringens was isolated from samples collected in the egg room, hatchers/hatch halls, separator room, processing room, and transport trucks. Furthermore, VITEK® mass spectrometry matrix-assisted laser desorption ionization time-of-flight results indicated a 99.9% genetic relatedness between hatchery and live bird isolates, demonstrating an epidemiologic link between clinically affected birds and the hatchery as a point source. This novel presentation of C. perfringens in young broilers warrants attention because proper development of the gastrointestinal tract in the first weeks of life is critical for competitive production in the modern broiler.

Reporte de caso- Nueva presentación de Clostridium perfringens en pollos de engorde jóvenes. La enteritis necrótica es una enfermedad intestinal importante de las aves comerciales asociada con un bajo rendimiento, alta mortalidad y pérdidas económicas significativas. En este reporte de caso, se describe una presentación nueva de enteritis necrótica en pollos de engorde jóvenes. Inicialmente, las granjas afectadas presentaron un aumento moderado en la mortalidad a los 19 días de edad o antes. Las granjas que presentaban el síndrome de la enfermedad pertenecían a dos complejos de la misma empresa. Sin embargo, todas las granjas obtuvieron pollitos de la misma incubadora. Los exámenes post mortem de la granja revelaron una enteritis de moderada a severa en la parte superior del intestino delgado caracterizada por ulceraciones de la mucosa multifocales, irregulares y similares a placas. Además, en algunas aves se observó adelgazamiento de la pared intestinal con la consiguiente distensión e hinchazón y una capa pseudomembranosa necrótica que cubría la mucosa. Las aves clínicamente afectadas se enviaron al Laboratorio de Investigación y Diagnóstico Avícola de la Universidad Estatal de Mississippi para una evaluación adicional. Las aves tenían entre cinco y once días de edad y presentaban lesiones macroscópicas similares. Se realizó cultivo de anaerobios y se aisló Clostridium perfringens de las secciones intestinales afectadas. También se realizaron muestreos ambientales en la incubadora para evaluar la presencia y carga de organismos clostridiales. Se aisló Clostridium perfringens de muestras recolectadas en la sala de huevos, incubadoras/salones de incubación, sala de separación, sala de procesamiento y camiones de transporte. Además, los resultados de la espectrometría de masas MALDI-TOF de VITEK® indicaron una relación genética del 99.9 % entre los aislados de la incubadora y de aves vivas, lo que demuestra un vínculo epidemiológico entre las aves clínicamente afectadas y la incubadora como fuente de infección común. Esta nueva presentación de C. perfringens en pollos de engorde jóvenes merece atención porque el desarrollo adecuado del tracto gastrointestinal en las primeras semanas de vida es fundamental para la producción competitiva en el pollo de engorde moderno.

Genomics accurately predicts antimicrobial resistance in Staphylococcus pseudintermedius collected as part of Vet-LIRN resistance monitoring.

Whole-genome sequencing (WGS) has changed our understanding of bacterial pathogens, aiding outbreak investigations and advancing our knowledge of their genetic features. However, there has been limited use of genomics to understand antimicrobial resistance of veterinary pathogens, which would help identify emerging resistance mechanisms and track their spread. The objectives of this study were to evaluate the correlation between resistance genotypes and phenotypes for Staphylococcus pseudintermedius, a major pathogen of companion animals, by comparing broth microdilution antimicrobial susceptibility testing and WGS. From 2017-2019, we conducted antimicrobial susceptibility testing and WGS on S. pseudintermedius isolates collected from dogs in the United States as a part of the Veterinary Laboratory Investigation and Response Network (Vet-LIRN) antimicrobial resistance monitoring program. Across thirteen antimicrobials in nine classes, resistance genotypes correlated with clinical resistance phenotypes 98.4 % of the time among a collection of 592 isolates. Our findings represent isolates from diverse lineages based on phylogenetic analyses, and these strong correlations are comparable to those from studies of several human pathogens such as Staphylococcus aureus and Salmonella enterica. We uncovered some important findings, including that 32.3 % of isolates had the mecA gene, which correlated with oxacillin resistance 97.0 % of the time. We also identified a novel rpoB mutation likely encoding rifampin resistance. These results show the value in using WGS to assess antimicrobial resistance in veterinary pathogens and to reveal putative new mechanisms of resistance.

Serotype and antimicrobial resistance patterns of Salmonella isolates from commercial birds and poultry environment in Mississippi.

To obtain information about Salmonella from commercial birds and poultry environments within Mississippi, 50 Salmonella enterica isolates were collected and characterized by intergenic sequence ribotyping (ISR) serotyping and by determining antimicrobial resistance. ISR assigned serotype to all 50 Salmonella enterica isolates whereas the Kauffman-White-LeMinor antibody-based scheme assigned serotype to 48. Agreement between both methods was K = 89.58. Within the set, 12 serotypes were detected. The antimicrobial resistance patterns (ARP) of 12 serotypes, namely Enteritidis, Typhimurium, Kentucky, Bredeney, Mbandaka, Saintpaul, Montevideo, Cubana, Lille, Senftenberg, Johannesburg, and one serotype UN0094, were determined using minimum inhibitory concentration values. The antibiograms demonstrated differences between Salmonella serotypes and among isolates of the same serotype. All isolates were 100% susceptible to enrofloxacin and trimethoprim/sulfamethoxazole. The number of antimicrobials to which the isolates were resistant ranged from two to nine. Twenty-two different ARPs were identified and ARP1, with resistance to spectinomycin and sulfadimethoxine, was most frequently observed. Forty isolates (80%) were resistant to three or more antimicrobials and were thus designated multidrug resistant. Detection of a unique serotype, and variation in antibiograms within the set, demonstrates that it is important to survey isolates periodically from a region to follow epidemiologic trends.