Caroline Pissetti

Fowl Typhoid (Salmonella Gallinarum) Outbreak in Japanese Quail (Coturnix coturnix japonica)

SUMMARY A fowl typhoid (FT) outbreak is reported in a flock of 400 Japanese quail (Coturnix coturnix japonica) at 91 days of age. Of these, 222 died suddenly, and necropsy revealed swollen liver and spleen with off-white to yellowish granules and reddish small intestine mucosa. Histopathology showed severe multifocal necrosis of liver and spleen (5/5), pulmonary congestion with macrophage infiltration in air capillaries (5/5), discrete interstitial nephritis (2/2), superficial necrosis of the intestinal mucosa with large numbers of coccobacilli (2/2), moderate peritonitis (2/2), and discrete airsacculitis (1/1). Anti-Salmonella immunohistochemistry (IHC) stained the cytoplasm of macrophages or free in the liver (5/5), spleen (5/5), lungs (4/5), kidneys (2/2) small intestine mucosa (2/2), cecum (1/1), bone marrow (1/1), air sacs (1/1), and ovary (1/1). In the heart (5/5), brain (2/2), esophagus (2/2), pancreas (2/2), proventriculus (2/2), gizzard (1/1), bursa of Fabricius (1/1), oviduct (1/1), and skeletal muscle (1/1) staining was observed only in the lumen of blood vessels. Salmonella Gallinarum was isolated in pure cultures of liver, spleen, lung, intestine, and blood samples of two birds. RESUMEN Reporte de Caso—Brote de tifoidea aviar (Salmonella Gallinarum) en codornices japonesas (Coturnix coturnix japonica). Se describe un brote de tifoidea aviar en un lote de 400 codornices japonesas (Coturnix coturnix japonica) de 91 días de edad, de las cuales 222 murieron súbitamente. Se practicó la necropsia de cinco animales y se observó hígado aumentado de tamaño con puntos blanco amarillentos, bazo difusamente pálido de color blanco amarillento y la mucosa del intestino delgado se observó de un color rojizo. A la histopatología, se observó en el hígado y en el bazo marcada necrosis multifocal (5/5), congestión del pulmón asociada con infiltración de macrófagos en los capilares aéreos (5 /5), nefritis intersticial leve (2/2), necrosis superficial de la mucosa intestinal con gran cantidad de bacterias cocobacilares (2/2), peritonitis moderada (2/2) y aerosaculitis leve (1/1). El examen inmunohistoquímico para Salmonella demostró una fuerte tinción en el citoplasma de los macrófagos o de manera difusa en el hígado (5/5), bazo (5/5), pulmón (4/5), riñón (2/2) mucosa del intestino delgado (2/2) y el ciego (1/1), médula ósea (1/1), sacos aéreos (1/1) y ovario (1/1). Por otra parte, en el corazón (5/5), cerebro (2/2), esófago (2/2), páncreas (2/2), proventrículo (2/2), molleja (1/1), bolsa de Fabricio (1/1), oviducto (1/1) y músculo esquelético (1/1) se observó tinción positiva sólo en el lumen de los vasos sanguíneos. Se aisló Salmonella Gallinarum en cultivo puro de muestras de hígado, bazo, pulmón, intestino y de la sangre de dos aves.

Detection of Genotipically Related Multi-resistant Escherichia coli Isolates in Pig Feces and Carcasses

Background: Antimicrobial resistant bacteria are considered a hazard not only for the treatment of animal diseases but also for public health. Commensal bacteria, such as Escherichia coli are considered a good indicator of antimicrobial resistance in the population, because it is a gut inhabitant and thus undergoes constant pressure of selection by the administration of antimicrobials. Regarding the public health, it is important to evaluate if resistant bacteria carried in the intestinal content of slaughter pigs can be found on the surface of pre chill carcasses. Therefore, the aims of this study were to evaluate the frequency of antimicrobial resistance in E. coli isolated from feces and pig carcasses; and to assess if multi-resistant isolates from both sources were phenotypically and genotypically related. Materials, Methods & Results: Two sampling cycles were conducted in three pig slaughterhouses (A, B and C). In each cycle, samples were collected form: i. feces deposited on the pen floor of the lairage; ii. surface of carcasses at the prechill step. Samples were submitted to a protocol of isolation and confirmation of Escherichia coli. Isolates were grouped according to the origin: feces (n = 355); carcasses (n = 319); and evaluated for antimicrobial resistance by agar diffusion test. Ninety two isolates presenting multidrug resistance profile were analyzed by pulsed-field gel eletrophoresis (PFGE). Among the 674 isolates of E. coli, 7.4% were susceptible to all tested antibiotics while 79.5% (536/674) were multi-resistant. The most frequent resistance patterns were displayed to tetracycline (Tet, 85.9%), ampicillin (Amp, 73.0%), sulfonamide (Sul, 70.0%), florfenicol (Flo, 65.0%) and nalidixic acid (Nal, 58.9%). The most frequent multi-resistance profile among isolates from both origins was [AmpFloNalSulTet]. Multiresistant isolates originated from feces and carcasses displaying genotypically related pulsotypes (≥70% similarity) were found in all three slaughterhouses. Discussion: In agreement with other studies, E. coli isolated from pig feces and carcasses demonstrated a high frequency of antimicrobial resistance and multi-resistance. The most frequent resistance profiles included antimicrobials frequently used on farm as well as drugs that have been banned as feed additives some years ago in Brazil. The selection of resistant strains may be related to the selection pressiondue to the use of antimicrobials in the pig production chain as well as the co-selection of resistance mediated by genes located in common genetic elements. Therefore, the ban of an individual drug is not always associated with the immediate disappearance of the resistance phenotype in the bacteria population. The fact that most multi-resistant E. coli isolates from carcasses belonged to pulsotypes related to those originated from feces samples indicates that resistant E. coli isolates selected on farm may be able to survive the slaughter process and be found on the carcass. In this case, the possibility of those strains being able to reach the population through the consumption of pork products may have to be considered. This hazard has motivated the ban of antimicrobial use in animals in some countries. However, the ban of antimicrobials use on farm is a controversial issue, due to the economical losses that may result from this measure. Therefore, the prudent use of antimicrobials on farm should be encouraged and its influence in the multi-resistance profile of the enteric microbiota should be further studied.

Equine salmonellosis in southern Brazil

The Salmonella sp. genus is identified in several species, and the zoonosis it causes is one of the most important types worldwide. The specifics of salmonellosis vary according to the function of the serovar involved, the species affected, age and predisposing factors. However, few cases of equine salmonellosis have been reported. This study presents ten confirmed salmonellosis cases in equines in southern Brazil. Six were adult animals with stress factors preceding the disease, while four were foals, three of which presented with hyperacute manifestations. The main clinical signs were diarrhea, anorexia, and hyperthermia. Lesions varied in distribution and severity, although fibrinonecrotic or necrohemorrhagic enteritis was observed in all animals, mainly in the large intestine (large colon and cecum—8/10) and small intestine (3/10). Substantial liquid content, mainly hemorrhagic, was observed in all animals. The most characteristic microscopic lesion was mucosa necrosis, which is often accompanied by fibrin deposition, followed by necrosis of follicular centers and vascular changes. Bacterial isolation revealed seven isolates. Five were serotyped, and the serovars Typhimurium and Anatum were associated with two cases each, while Muenster was associated with a case whose lesion pattern varied. Immunohistochemical staining was positive in all cases. All diagnoses were based on the clinical history, macroscopic and histological lesions, and the bacterial isolation and/or immunostaining associated with histological lesions.