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.

Testicular Atrophy and Epididymitis-Orchitis Associated with Infectious Bronchitis Virus in Broiler Breeder Roosters.

Infectious bronchitis is a respiratory disease of chickens caused by a gammacoronavirus named infectious bronchitis virus (IBV). In addition to affecting the respiratory tract, IBV may also induce urogenital infections, leading to nephropathogenic disease, false layer syndrome in laying hens, and epididymal lithiasis and epididymitis in males. Here, we report a case of decreased reproductive efficiency due to male infertility in 33- to 38-wk-old broiler breeders. At necropsy, the males presented with urates deposited on the skin around the vent and testicular asymmetry due to marked unilateral atrophy. Histopathology revealed lymphocytic epididymitis, epididymal lithiasis, and orchitis. IBV antigen was detected within collecting and efferent ducts of epididymides by immunohistochemistry. IBV strain DMV/1639 was detected by reverse transcription-quantitative PCR in pools of testes, oviducts, tracheas, cecal tonsils, and kidneys from a 37-wk-old affected flock. This report shows evidence of the role of IBV in male chicken infertility and highlights the importance of performing molecular surveillance of IBV to monitor vaccine strains and to detect emerging variants that can potentially hinder production.

Reporte de caso- Atrofia testicular y epididimitis-orquitis asociadas con el virus de la bronquitis infecciosa en gallos reproductores pesados. La bronquitis infecciosa es una enfermedad respiratoria del pollo causada por un gammacoronavirus llamado virus de la bronquitis infecciosa (con las siglas en inglés IBV). Además de afectar el tracto respiratorio, el IBV también puede inducir infecciones urogenitales, lo que conduce a enfermedad nefropatogénica, síndrome de la falsa ponedora en gallinas de postura y litiasis epididimaria y epididimitis en machos. En este reporte se describe un caso de disminución de la eficiencia reproductiva debido a la infertilidad de machos en reproductores pesados de 33 a 38 semanas de edad. En la necropsia, los machos presentaron depósitos de uratos sobre la piel alrededor de la cloaca y asimetría testicular por atrofia unilateral marcada. La histopatología reveló epididimitis linfocítica, litiasis epididimaria y orquitis. Antígenos del virus de la bronquitis infecciosa se detectaron dentro de los conductos colectores y eferentes de los epidídimos mediante inmunohistoquímica. La cepa del virus de la bronquitis DMV/1639 se detectó mediante transcripción reversa y PCR cuantitativa en muestras agrupadas de testículos, oviductos, tráqueas, tonsilas cecales y riñones de una parvada afectada de 37 semanas de edad. Este reporte muestra evidencia del papel del virus de la bronquitis infecciosa en la infertilidad de los pollos machos y destaca la importancia de realizar una vigilancia molecular de este virus para monitorear las cepas vacunales y detectar variantes emergentes que potencialmente pueden dificultar la producción.

A Field Study of Histologic and Bacteriologic Characterization of Femoral Head Separation and Femoral Head Necrosis.

Histologic and bacteriologic features for groups of average 31-day-old broilers displaying three gross categories of femoral head alterations were documented. Categories included simple femoral head separation (FHS), femoral head transitional changes (FHT), and femoral head necrosis (FHN). Groups with grossly normal (NORM) femoral heads and cull birds with FHN and having gross signs of sepsis (Cull-FHN) were also included in the study. There was a 10% occurrence of positive bacterial cultures for all birds tested. Most positive cultures (33%) were found in the Cull-FHN group, while only a 12% occurrence was seen in the FHS group, and no positives were present in the FHT or FHN groups. A 14% total occurrence of femoral bacterial chondronecrosis with osteomyelitis or simple osteomyelitis (BCO-O) was observed. A progressive increase in the prevalence of BCO-O was apparent between groups going from NORM (0%), FHS (4%), FHT (14%), FHN (13%), and reaching a maximum of 67% in the Cull-FHN group. Minimal to mild femoral head cartilage necrosis was present in 40% of NORM broilers and 100% of the FHS, FHT, and FHN groups, but at moderate severity in 20% of the Cull-FHN group. Thus, the majority of FHN cases were associated with aseptic cartilage necrosis rather than BCO-O. These findings suggest that aseptic cartilage necrosis may be as important as septic necrosis as a cause of gross femoral head disease. A 26% overall occurrence was seen for hip synovitis-arthritis, but group differences were not statistically significant. Synovitis was not seen in the NORM group and was present in some (12%) of the FHS group but was observed at a high rate in both the FHN (43%) and the Cull-FHN (50%) groups. Morphometric measurements demonstrated that the area size of femoral fibrous cortical defects or "cutback zones" were generally larger for all gross categories relative to NORM, with a significant difference between NORM and FHS groups. This study underscores the multifactorial etiology of FHN and the importance of conducting both histologic and bacteriologic evaluations in which gross evidence of FHN or BCO-O occurs.

High incidence of glomerulonephritis associated with inclusion body hepatitis in broiler chickens: routine histopathology and histomorphometric studies.

During the routine histologic evaluation of an outbreak of inclusion body hepatitis (IBH) in Mississippi broilers, a high incidence of renal enlargement and glomerulonephropathy was observed in the birds presenting classic hepatic pathology. Characteristic intranuclear adenoviral inclusion bodies were demonstrated in the livers of these birds, and fowl adenovirus was identified by viral isolation and by PCR. The glomerular lesions were consistent with proliferative or membranoproliferative forms of glomerulonephritis. Histomorphometric evaluations were performed to generate a more quantitative analysis of altered glomerular size and cellularity, to detect statistically significant borderline changes, and to get a clearer insight into the incidence of the glomerular alterations. Marked increases in both the average glomerular size (area) and the total glomerular cellularity were observed for the affected glomeruli relative to normal controls. The average glomerular area values for normal glomeruli in the peripheral subcapsular cortical and central cortical kidney regions were 1791 microm2 and 5302 microm2, respectively. In contrast, glomerular measurements for kidneys exhibiting glomerulonephritis by routine histopathology, had average values for the two regions of 4429 microm2 and 11,063 microm2. The average glomerular cell counts for the two regions in controls were 44 and 107 cells/ glomeruli, while averages for birds with glomerulonephritis were 85 and 193 cells/glomeruli. The proportion of IBH-associated glomeruli greater than two standard deviations above the mean glomerular size of the normal controls was 52% for the central region and 62% for the peripheral region.

Epidemiology and effect on production parameters of an outbreak of inclusion body hepatitis in broilers.

In 2007, an inclusion body hepatitis (IBH) outbreak affected several broiler farms in Mississippi. Results of logistic regression analyses showed significant associations between IBH occurrence and high enzyme-linked immunosorbent assay geometric mean titers for infectious bursal disease virus. However, there was no association between IBH occurrence and chicken infectious anemia virus status. Results of linear regression model analyses showed significant associations between IBH occurrence with average weight and with cost deviation. Broiler meat production cost was $0.0058/kg more expensive to produce when IBH occurred. Although feed conversion was higher with IBH occurrence, the association was not significant. IBH onset in the first farms affected occurred between 19 and 30 days of age, whereas in the last farms affected, IBH onset occurred as early as 10 days.