Effect of silica-sprayed collection tubes on synovial fluid bacterial culture.

INTRODUCTION: Silica-sprayed tubes (SSTs) are often used to transport synovial fluid samples in equine practice. They promote the coagulation of the sample. The objective of the study is to evaluate the effect of SST on bacterial culture. MATERIALS AND METHODS: The study was divided into two parts: sterile saline (Part A) and synovial fluid (Part B). Four common bacteria associated with equine synovial sepsis were used: Streptococcus pyogenes, Escherichia coli, Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). Three collection tubes were used: STT, plain (no-additives) and brain and heart infusion (BHI) broth. Bacteria were cultured in horse blood agar plates for 48 h. Outcome variables were negative culture, positive culture and total number of colony-forming units (CFUs). Statistical analysis was performed using Mann-Whitney U test, and significance was set at p < 0.05. RESULTS: The total number of agar plates read was 1557 (779 saline; 778 synovial fluid). Total negative cultures were 25/779 on saline and 3/778 on synovial fluid. In broth, maximum growth CFU was achieved after 8 h for both saline and synovial fluid for all bacteria. S. pyogenesand E. coli produced a significantly lower number of CFU when in SST compared to plain or broth after 4 h, whereas S. aureus (American Type Culture Collection [ATCC] and MRSA) only after 24 h. DISCUSSION: Silica-containing tubes reduced bacterial proliferation, whereas the use of a BHI broth provided the highest bacterial load in the sample. The use of SST may have a negative effect on bacterial proliferation in samples obtained from clinical cases.

Proof of concept for multiplex detection of antibodies against Chlamydia species in chicken serum using a bead-based suspension array with peptides as antigens.

The available differentiating tests for Chlamydia are based on detection of genetic material and only give information about the actual infection status, but reveal nothing of past infections. As the use of serological methods increases the window of detection, the goal of this study was to investigate if it is possible to develop a differentiating serological test for antibodies against Chlamydia species in chicken sera. Focus was on C. psittaci, C. gallinacea, and two closely related species, i.e. C. abortus and C. avium. To enable differentiating serology, a bead-based Luminex suspension array was constructed, using peptides as antigens, derived from known immunoreactive Chlamydia proteins. For the majority of these peptides, species-specific seroreactivity in mammalian sera has been reported in literature. The suspension array correctly identified antibodies against various Chlamydia species in sera from experimentally infected mice, and was also able to differentiate between antibodies against C. psittaci and C. gallinacea in sera from experimentally infected chickens. In field sera, signals were difficult to interpret as insufficient sera from experimentally infected chickens were available for evaluating the seroreactivity of all peptides. Nevertheless, results of the suspension array with field sera are supported by published data on the occurrence of C. gallinacea in Dutch layers, thereby demonstrating the proof of concept of multiplex serology for Chlamydial species in poultry.

Eficácia in sílico do florfenicol no tratamento de pododermatite infecciosa por Fusobacterium necrophorum em ovelhas / In sílico efficacy of florfenicol in the treatment of Fusobacterium necrophorum infectious pododermatitis in sheep

Objetivou-se comparar o efeito in silico do florfenicol nas doses de 20 e 30 mg/Kg em ovinos pelas vias intravenosa (IV) e intramuscular (IM), usando a modelagem PK/PD. Realizou-se uma simulação de Monte Carlo com base nos dados de concentração plasmática de um estudo publicado anteriormente. Calculou-se a área sob a curva (ASC) e as taxas de eficácia do florfenicol para os efeitos bacteriostático, bactericida e de erradicação bacteriológica. A dose de 20 mg/Kg IV demonstrou efeitos de erradicação de 100, 93 e 0% para CIM de 0,5, 1 e acima, respectivamente. O efeito bacteriostático foi de 99 e 90% para CIM de 4 e 2 µg/ml, enquanto o bactericida foi de 14% para CIM de 2 µg/ml. A dose de 30 mg/Kg IV apresentou 100% de erradicação para CIM de 1 µg/mL e 100% de efeito bactericida para CIM de 2 µg/mL. Há 100% de efeito bacteriostático em CIM de 4 µg/ml. As doses de 20 e 30 mg/Kg IM mostraram 100% de erradicação para CIM até 1 µg/mL e 0% para CIM maiores. O efeito bacteriostático foi mantido em 100% para uma CIM de 4 µg/mL em ambas as doses. Este estudo mostra o efeito de erradicação bacteriológica do florfenicol nas doses de 20 e 30 mg/Kg, IV e IM. Recomenda-se que seja feito um estudo de eficácia in vivo com a dose de 30mg/Kg IM em ovinos infectados por F. necrophorum com MIC superior a 2 µg/mL.

We aimed to compare the in silico effect of florfenicol at doses of 20 and 30 mg/Kg in sheep by intravenous (IV) and intramuscular (IM) routes, using PK/PD modeling. We performed a Monte Carlo simulation based on plasma concentration data from a previously published study. We calculated the area under the curve (AUC) and the efficacy rates of florfenicol to bacteriostatic, bactericidal, and bacteriological eradication effects. The dose of 20 mg/Kg IV demonstrated 100, 93, and 0% eradication effects for MICs of 0.5, 1, and above, respectively. The bacteriostatic effect was 99 and 90% for MIC of 4 and 2 µg/ml, while the bactericide was 14% for MIC of 2 µg/ml. The 30 mg/Kg IV dose showed 100% eradication for MIC of 1 µg/mL and 100% bactericidal effect for MIC of 2 µg/mL. There is a 100% of bacteriostatic effect at MIC of 4 µg/ml. Doses of 20 and 30 mg/Kg IM showed 100% eradication for MIC up to 1 µg/mL and 0% for MIC above. The bacteriostatic effect was maintained at 100% for a MIC of 4 µg/mL at both doses. This study shows the bacteriological eradication effect of florfenicol at doses of 20 and 30 mg/Kg, IV, and IM. Therefore, we recommend an in vivo efficacy study with a dose of 30mg/Kg IM in sheep infected with F. necrophorum with MIC greater than two µg/mL.

Evaluation of mare endometrial cytology using the novel cytotape technique.

The cytobrush is considered the method of choice to obtain endometrial samples. Rigid brush fibers, however, may induce endometrial irritation and bleeding, or cell fragmentation, decreasing quality and diagnostic value of the samples. It was hypothesized that samples collected using a novel cytotape would provide sample smears of greater quality and less blood contamination than the cytobrush. Endometrial samples were collected with a cytotape and a cytobrush from ten mares without endometritis. Endometritis was then induced with artificial insemination, and samples were again collected 6 h after insemination. A cytology smear and bacterial culture were prepared from each sample. The collection methods and times were compared in terms of number and integrity of endometrial cells; number, integrity, and percentage of neutrophils; number of red blood cells, and number of colony-forming units. Frequency of positive cytology and culture was compared when there was use of each technique. The sensitivity, specificity, positive predictive value, and negative predictive value of cytology and culture for each technique was calculated using endometrial biopsy as the gold standard. While all samples had adequate and comparable cellularity and cell integrity, cytotape samples had less red blood cell contamination compared to cytobrush samples (P < 0.05). The number and percentage of PMNs, frequency of positive cytology diagnosis, number of colony-forming units and frequency of positive cultures did not differ between collection methods. In conclusion, the cytotape is a rapid, easy, and practical technique that can provide endometrial samples with similar diagnostic value to the cytobrush, but with less blood contamination.

A filter-assisted culture method for isolation of Treponema spp. from bovine digital dermatitis and their identification by MALDI-TOF MS.

Digital dermatitis (DD) is a major infectious foot disease of cattle worldwide. Some DD stages are associated with lameness, and the disease has significant economic and animal welfare consequences. The pathogenesis of the disease is not yet fully understood, but Treponema spp. have been associated consistently with clinical cases. Isolation of these fastidious bacteria is difficult and cumbersome. We describe an improved method enabling the culturing of the 3 Treponema spp. (T. pedis, T. phagedenis, and T. medium) from bovine foot specimens derived from DD lesions, using a combination of membrane filtering and subsequent growth on selective agar media. The entire procedure from sampling to verification of individual Treponema spp. takes up to 24 d. In addition, we established a MALDI-TOF MS-based identification method to be applied for confirmation of the different Treponema spp. This scheme provides an unambiguous, simple, and straightforward identification procedure for DD-associated Treponema spp.

Growth of adenocarcinoma from canine pleural fluid on aerobic bacterial culture.

We report a case of canine adenocarcinoma with multi-organ metastasis in which colonies of adenocarcinoma cells grew upon aerobic bacterial culture of pleural effusion. Stained agar colonies were highly similar to rare suspicious cells seen on cytologic examination of the pleural effusion, as well as rare cells seen on cytologic examination of pancreatic and gastric wall fine-needle aspirates. Cells from colonies growing on agar media were mildly immunoreactive for cytokeratin. Histologic examination of tissues obtained at autopsy revealed pancreatic adenocarcinoma with vascular invasion and nodal, gastric, pulmonary, and pleural metastasis.

Mannheimia haemolytica biofilm formation on bovine respiratory epithelial cells.

Mannheimia haemolytica is the most important bacterial agent associated with the bovine respiratory disease complex (BRDC), which causes worldwide economic losses to the cattle industry. M. haemolytica cells initially colonize the tonsillar crypts in the upper respiratory tract of cattle, from where they can subsequently descend into the lungs to cause disease. Many bacteria exist as biofilms inside their hosts. We hypothesize that M. haemolytica colonization of cattle during its commensal state may include biofilm formation. To begin to assess this possibility, we developed an in vitro system to study biofilm formation directly on bovine respiratory epithelial cells. Using fixed primary bovine bronchial epithelial cells, we observed M. haemolytica biofilm formation after a 48h incubation period at 37°C. Addition of mucin, the main component of mucus present in the upper respiratory tract, decreased M. haemolytica biofilm formation on bovine epithelial cells. We investigated the effects of prior viral infection of the epithelial cells on subsequent biofilm formation by M. haemolytica and found negligible effects. Utilization of this model system will provide new insights into the potential role of biofilm formation by M. haemolytica in the pathogenesis of BRDC.

Effects of processing delay, temperature, and transport tube type on results of quantitative bacterial culture of canine urine.

OBJECTIVE: To determine the impact of processing delay, temperature, and transport tube type on results of quantitative bacterial culture (QBC) of canine urine. DESIGN: Diagnostic test evaluation. SAMPLE: 60 mL of pooled urine from 4 dogs, divided into six 10-mL aliquots. PROCEDURES: Urine aliquots were spiked with bacteria from 1 of 6 independent Escherichia coli cultures to achieve a target bacterial concentration of 10(5) CFUs/mL. One milliliter from each aliquot was transferred into 5 silicone-coated clot tubes (SCTs) and 5 urine transport tubes (UTTs). Samples were stored at 4°C (39°F) and 25°C (77°F) for 0, 8, and 24 hours, and then standard QBCs were performed. RESULTS: Median bacterial concentration for urine samples stored in a UTT for 24 hours at 4°C was lower than that for samples stored in an SCT under the same conditions. Conversely, a substantial decrease in median bacterial concentration was identified for samples stored for 24 hours in an SCT at 25°C, compared with the median concentration for samples stored in a UTT under the same conditions. Median bacterial concentration in samples stored in an SCT at 25°C for 24 hours (275 CFUs/mL) was less than the cutoff typically used to define clinically important bacteriuria by use of urine samples obtained via cystocentesis (ie, > 1,000 CFUs/mL). CONCLUSIONS AND CLINICAL RELEVANCE: Canine urine samples submitted for immediate QBC should be transported in plain sterile tubes such as SCTs. When prolonged (24-hour) storage at room temperature is anticipated, urine samples should be transported in UTTs.

Detection of Helicobacter spp. DNA in the colonic biopsies of stray dogs: molecular and histopathological investigations.

BACKGROUND: In dogs, the gastric Helicobacter spp. have been well studied, but there is little information regarding the other parts of the alimentary system. The incidence of Helicobacter spp. infection in dogs is largely unknown and to our knowledge there are no data about their potential pathogenic role. In light of these considerations, the aims of this study were (i) to assess the prevalence of Helicobacter spp. in colonic biopsies of healthy and symptomatic stray dogs also (ii) we isolate and characterize helicobacters in canine colonic biopsies to compare the commonly used tests for the identification of Helicobacter spp. and to determine the occurrence of these species in dogs. METHODS: Tissues from fifteen stray dogs (8 males and 7 females, age 6 months -10 years) were used in this study. From each stray dog, multiple colonic biopsies were taken for PCR. Biopsies for PCR of cecum and colon were immediately frozen and stored at -20°C until DNA extraction. Samples for histological examination were fixed in 10% neutral buffered formalin and embedded in paraffin wax. RESULTS: In the cecum and colon, Helicobacter spp. DNA was detected in all dogs. H.canis, H.bizzozeronii, H. bilis, H.felis, H.salomonis and H.pylori Identified by specific polymerase chain reaction. Histopathology demonstrated that Helicobacter organisms were localized within the surface mucus and the intestinal crypts. Dogs with heavy Helicobacter spp. colonization were significantly in younger as well as had a higher level of mucosal fibrosis/atrophy than dogs with uncolonized or poorly colonized biopsies (p<0.05). CONCLUSIONS: We have indicated that the crypts of the cecum and colon of healthy and symptomatic dogs are heavily colonized by Helicobacter spp.. Combined molecular and histological approaches demonstrated that enterohepatic Helicobacter spp. infection is rather common in colonic biopsies of healthy and symptomatic stray dogs, with Helicobacter spp. specialy H. canis, H.bizzozeroni, H.billis, H.felis and H. salomonis identified as the most common species. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1957989294118782.

Comparison of 3 culture methods and PCR assays for Salmonella gallinarum and Salmonella pullorum detection in poultry feed.

To detect Salmonella gallinarum or Salmonella pullorum in artificially contaminated poultry feed, 9 culture combinations were compared, including 3 preenrichment/enrichment methods (tryptic soy broth plus ferrous sulfate/tetrathionate Hajna, tryptic soy broth plus ferrous sulfate/selenite cystine broth, and Salmosyst) in combination with 3 selective agars (xylose lysine desoxicholate agar added with tergitol 4, EF-18, and Önöz), respectively. Additionally, a single PCR technique was applied combined with 2 different preenrichment media (tryptic soy broth plus ferrous sulfate and Salmosyst). The specificity and positive predictive value were 1 for all methods. There were some differences among Salmonella strains for sensitivity and accuracy in the culture and Salmosyst-PCR methods. The sensitivity and accuracy values were less than 0.60 and 0.64, respectively, whereas the negative predictive values were between 0.12 and 0.23. Two PCR methods did not show any difference in the parameters of performance evaluated. Kappa coefficients showed good agreement between both methods. None of the culture combinations was able to detect S. gallinarum or S. pullorum when the inoculum was less than 3 × 10² cfu/25 g, except the Salmosyst broth method, which could recover S. gallinarum from 3 × 10¹ cfu/25 g onward. Overall, there were differences in the detection limits among the strains and methods used. In general, the 3 selective plating media did not show any significant difference in the parameters of performance studied for each strain. On the other hand, the agreements were slight to fair when culture methods were compared among them and with both PCR methods. The differences in the detection levels that were obtained using these methods and the difficulty in detecting S. gallinarum or S. pullorum in feed represent a potential problem when a poultry feed sample is considered to be negative. It is highly recommended to use at least 2 methods to increase the chances of detecting S. gallinarum or S. pullorum in poultry feed.

Mycobacterium avium subspecies paratuberculosis: an insidious problem for the ruminant industry.

Mycobacterium avium subspecies paratuberculosis is considered as one of the most serious problems affecting the world's ruminant industry due to its significant impact on the global economy and the controversial issue that it may be pathogenic for humans. M. avium subspecies paratuberculosis is the causative agent of Johne's disease in animals and might be implicated in cases of human Crohn's disease. We provide an insight into M. avium subspecies paratuberculosis from some bacteriological, clinical, and molecular epidemiological perspectives.

Factors influencing the prevalence of subclinical mastitis in lactating dromedary camels in Riyadh Region, Saudi Arabia.

The purpose of this study was to determine the prevalence of subclinical mastitis in camels in Riyadh, Saudi Arabia and the factors influencing its incidence. A total of 740 quarter milk samples were collected from 47 camel herds belonging to Majahim, Maghatir, Shu'l, and Sufer breeds. California mastitis test (CMT) was used as a screening test for subclinical mastitis. Samples giving negative or trace CMT scores (0) were assigned to healthy quarters, while those giving positive scores of 1+ to 3+ were assigned to subclinically affected quarters. Logistic regression was used to assess the association of breed, parity, and stage of lactation with the prevalence of subclinical mastitis. Milk fat, protein, lactose, solid nonfat percentages and Na, Ca, and K concentrations were compared in CMT-positive versus healthy quarters. One third (33%) of tested quarters had subclinical mastitis based on CMT. The estimated probability of subclinical mastitis with the combined effects of breed, parity, and stage of lactation ranged from 15.8% to 54.6%. The risk of subclinical mastitis increased significantly with parity and with the early stage of lactation. The Shu'l breed had significantly higher prevalence of subclinical mastitis than other breeds. Significant decreases in protein, lactose, and solid nonfat, Ca and K concentrations and increase in Na concentrations were associated with subclinical mastitis. In conclusion, subclinical mastitis is prevalent in Saudi camels, and its incidence is influenced by breed, parity, and stage of lactation.

Comparison of three diagnostic methods to identify subclinical endometritis in mares.

The objective of this study was to compare the accuracy of a uterine swab (US), a cytological brush (CB) and an endometrial biopsy (EB) to detect subclinical endometritis in mares. Cytological and bacteriological results of all three techniques were related to histological occurrence of polymorphonuclear neutrophils (PMNs) in the stratum compactum, commonly known as 'best standard'; to diagnose endometritis. Samples were taken from 55 mares of different breeds without clinical signs of endometritis. Samples for US, CB and EB were collected, smeared on a microscopic slide and cultured for bacterial growth. Endometrial biopsy samples were additionally stored in 4% formaldehyde for histological analysis. Bacteriological cultures and cytological samples of all techniques were classified as negative (no uterine pathogens in monoculture; < 2% PMNs) or positive (uterine pathogens in > 90% of the grown colonies; > 2% PMNs) for endometritis. Uterine pathogens were diagnosed in 20.0% of the mares. Isolation of pathogens was not associated with positive cytological findings (r = -0.23; P = 0.87). None of the six mares with an Escherichia coli infection (10.9%) showed a positive cytological result. In contrast, two of five mares infected with Streptococcus zooepidemicus had a positive cytological result. Histologically, the presence of PMNs in the stratum compactum was regarded as positive for endometritis when the mare was in diestrus at time of sampling. Compared to the 'best standard', sensitivity for cytology of CB, US and EB was 0.17, 0.00 and 0.25, respectively. Specificity for cytology of CB, US and EB was 0.83, 0.93 and 0.85, respectively. Sensitivity of uterine culture was 0.25, 0.33 and 0.25 for CB, US and EB, respectively. Specificity for culture of CB, US and EB was 0.80, 0.83 and 0.95, respectively. In conclusion, cytological or bacteriological examinations alone provide a high incidence of false negative results. Sensitivity of cytology combined with bacteriology of CB was 0.42. A combination of a bacteriological and a cytological examination of a CB sample improved the diagnostic performance in subfertile mares. Based on these results, we can recommend the CB to improve the diagnosis of subclinical endometritis in the mare compared to the US alone as currently used routine method.

Comparison of sampling methods, culture, acid-fast stain, and polymerase chain reaction assay for the diagnosis of mycobacteriosis in ring-neck doves (Streptopelia risoria).

Even when different diagnostic modalities are available, mycobacteriosis is difficult to diagnose in a live bird. To investigate the diagnostic value of sampling different tissues and using different diagnostic methods, we evaluated results of mycobacterial culture, Ziehl-Neelsen (ZN) staining, and single-amplification polymerase chain reaction assay (PCR) of 18 ring-neck doves (Streptopelia risoria) with confirmed natural infection with Mycobacterium avium avium. Results of testing liver biopsy, duodenal aspirate, and bone marrow aspirate samples and liver and spleen samples collected at necropsy were compared. Results showed the use of one single technique did not allow identification of all infected birds. In liver biopsy and bone marrow aspirate samples, culture had the highest sensitivity, whereas PCR assay and ZN staining had low sensitivity, and their combination was less sensitive than culture alone. Examination of ZN staining of the intestinal aspirate samples failed to detect infection in most birds. More splenic lesions contained acid-fast organisms than did liver lesions, suggesting that splenic biopsy may have the greatest potential for diagnosis of mycobacterial infection antemortem. Sensitivity was higher for postmortem examination of multiple liver sections than of a single biopsy section; therefore, obtaining multiple liver biopsy sections may increase detection of mycobacteria. Examination of multiple tissues and the use of several different diagnostic techniques significantly increases the probability of diagnosis of mycobacteriosis.

Depuración bacteriana y física de la almeja Polymesoda solida a pequeña escala / Bacterial and physical depuration of the clam Polymesoda solida at pilot scale

El consumo de moluscos bivalvos ha sido asociado con infecciones microbianas aún en casos donde los mismos cumplen con los parámetros de calidad bacteriológica. El proceso de depuración se realiza con el fin de eliminar, de forma natural, los microorganismos presentes en moluscos bivalvos, los cuales han sido acumulados por su proceso de filtración. En este estudio se determinó la tasa de depuración de indicadores potenciales de contaminación. Se realizaron cuatro experimentos con la almeja Polymesoda solida, la cual poseía niveles altos de índices contaminantes de forma natural. Para evaluar el proceso de depuración se utilizaron como indicadores bacterianos los coliformes totales (CT), coliformes fecales (CF), estreptococos fecales (SF), enterococos (EN) y bacterias aerobias mesófilas (AM). El contenido inorgánico total (CIT) se utilizó como indicador del contenido de arena. La desinfección del agua marina, preparada artificialmente, se realizó irradiando con luz UV durante 48 h. El proceso de depuración se realizó durante 120 horas (5 días) a 28°C y 5 UPS, en tanques de 150 L de capacidad. La tasa de remoción bacteriana y física en Polymesoda solida fue más eficiente (80 por ciento) durante las primeras 72 h, alcanzando una calidad bacteriológica y física adecuada para el consumo, sin importar que los ejemplares fueron recolectados de sitios que no cumplían con los niveles aceptables de calidad.

The consumption of shellfish has been associated with microbial infections even in cases where shellfish complied with the current regulation, which is based on bacterial analysis. Depuration processes try to eliminate microorganisms using seawater to allow living, filter-feeding shellfish to naturally purge themselves from agents they accumulated from the environment. In this study, depuration rates of potential indicators were estimated. Four experiments, with naturally-contaminated shellfish (Polymesoda solida), were performed. For evaluating the shellfish depuration process, total coliforms (TC), fecal coliforms (FC), fecal streptococcus (FS), enterococcus (EN) and mesophilic aerobic bacteria (MAB) were evaluated as bacterial indicators. Total inorganic content was used as physical indicator. Artificial prepared seawater of the depuration tank was disinfected by UV irradiation. Depuration removal rates of experiments running for 120 hours (five days) at 28°C, 5 psu, in a 150 L tanks were effective (80 percent) and more efficient during the first 72 hours, allowing an adequate bacterial and physical quality for consumption after this time, no matter the clams were collected in contaminated areas which do not complain with maximal allowable level.

Estudo comparativo de métodos complementares para o diagnóstico da tuberculose bovina em animais reagentes à tuberculinização / Comparative study of complementary diagnostic methods of bovine tuberculosis on skin-test reactive cattle

A tuberculose bovina é uma enfermidade infecciosa de ocorrência mundial. O teste intradérmico é o método padrão para seu diagnóstico da tuberculose, embora possa carecer de sensibilidade e especificidade. O presente estudo teve como objetivo avaliar diferentes métodos complementares para o diagnóstico da tuberculose bovina incluindo os exames macroscópicos de tecidos, histopatológico, bacteriológico e ELISA. Um total de 97 bovinos reagentes à prova de tuberculinização foi testado, e amostras de tecidos e soro foram colhidas no momento do abate. Do total de bovinos examinados, 70 (72,16 por cento) apresentaram lesão macroscópica sugestiva de tuberculose. Na avaliação histopatológica, 63 animais (64,95 por cento) apresentaram lesão granulomatosa característica. Assim, a histopatologia concordou com a avaliação macroscópica em 92,78 por cento das amostras. Em 47 (48,45 por cento) amostras foram visualizados Bacilos Álcool Ácido Resistentes (BAAR), todas positivas à histopatologia ou à avaliação macroscópica.(ACom relação à cultura bacteriológica, foram isolados Mycobacterium bovis em apenas 11 amostras (11,34 por cento). Quanto ao desempenho do teste de ELISA, 33 (34,02 por cento) soros foram reativos. O exame macroscópico detalhado associado ao exame histopatológico, devido à sua alta especificidade, são recomendados como ferramentas complementares e podem ser utilizados para confirmar os casos duvidosos no abatedouro.

Bovine tuberculosis is an infectious disease of world-wide occurrence. The intradermal tuberculin test is the standard test for its detection, but it can lack both sensitivity and specificity. The purpose of this study was to compare the efficiency of different complementary methods for the diagnosis of bovine tuberculosis such as macroscopic, histopathological, bacteriological analysis and Enzyme-linked immunosorbent assay (ELISA). A total of 97 skin-test reactive animals were studied, and tissues and serum samples were collected from all of them at the moment of the slaughter. Seventy animals (72.16 percent) showed macroscopic lesions suggestive of tuberculosis. At the histopathological exam, sixty three (64.95 percent) presented typical granulomatous lesions. Therefore, histopathology agreed with macroscopic inspection in 92.78 percent of the samples. Acid-fast bacilli were observed in tissues samples from 47 (48.45 percent) animals, all of them also positive either at macroscopic inspection or to histopathology. In reference to the bacterial culture, only 11 (11.34 percent) tissues samples yielded Mycobacterium bovis. Thirty three (34.02 percent) serum samples were reactive at ELISA. Detailed visual inspection as well as histopathology, due to its high specificity, are suggested as complementary tools and may be used for confirming doubtful cases of bovine tuberculosis at the slaughterhouse.

The use of the milk ring test and rose bengal test in brucellosis control and eradication in Nigeria.

In this study, milk and blood samples collected simultaneously from 532 trade cows to be slaughtered at Bodija abattoir, Ibadan (southwestern, Nigeria) were examined for antibodies to Brucella using the milk ring test (MRT) and the rose bengal test (RBT). Overall, 18.61% of the milk samples were positive according to the MRT, while 9.77% of the serum samples were positive according to the RBT. The difference was highly significant (Chi-square value 16.33; P < 0.05); only 32 (6.02%) of the samples were positive for both tests. The Red Bororo breed of cattle and the White Fulani had the highest positive rates, namely 20.93% and 11.69% for the MRT and RBT respectively. No conclusion can be drawn about sensitivity because we do not know the true status of the animals tested. It is, however, obvious that although the MRT and RBT are 1st-line screening tests for brucellosis in cows in some countries, their lack of specificity is of concern. Therefore, the requirement for other confirmatory tests that are more specific should be considered for control and eradication of the disease, especially in Nigeria.

Comparison of IS900 tissue PCR, bacterial culture, johnin and serological tests for diagnosis of naturally occurring paratuberculosis in goats.

Comparative efficacy of an IS900 tissue PCR, bacterial culture, johnin, agar-gel immunodiffusion (AGID) and absorbed-ELISA tests was investigated in 43 goats naturally infected with paratuberculosis. On histological examination, tissue sections from all animals showed typical granulomatous inflammatory changes. The lesions were classified as multibacillary (MB) (n=30), which had diffuse granulomatous lesions with abundant acid-fast bacilli (AFB), and paucibacillary (PB) (n=13), which had focal or multifocal granulomatous lesions with few AFB. The sensitivities of johnin test, tissue culture, faecal culture, tissue PCR, AGID and ELISA were 68% (17/25), 100% (30/30), 84.6% (22/26), 100% (30/30), 96.2% (25/26) and 100% (26/26) in MB goats, and 88.8 (8/9), 46.1% (8/13), 40% (4/10), 61.5% (8/13), 50% (5/10), and 70% (7/10) in PB goats, respectively. Except for the johnin test, which showed higher sensitivity in PB goats, all other tests displayed significantly higher sensitivities in MB goats. The results indicate the usefulness of tissue PCR, culture and serological tests in the diagnosis of clinically affected paratuberculous goats, especially with multibacillary pathology.

Evaluation of modified Wright-staining of urine sediment as a method for accurate detection of bacteriuria in dogs.

OBJECTIVE: To compare the findings of light microscopic evaluation of routine unstained wet-mounted preparations and air-dried, modified Wright-stained preparations of urine sediment with results of quantitative aerobic bacteriologic culture of urine. DESIGN: Masked prospective study. SAMPLE POPULATION: 459 urine samples collected by cystocentesis from 441 dogs. PROCEDURE: Urinalyses and quantitative bacteriologic cultures of urine were performed. Unstained wet-mounted preparations and air-dried, modified Wright-stained urine sediment preparations were examined by light microscopy for the presence of bacteria. RESULTS: Compared with results of quantitative bacteriologic culture, routine unstained preparations and modified Wright-stained preparations had sensitivities of 82.4% and 93.2%, specificities of 76.4% and 99.0%, positive predictive values of 40.1% and 94.5%, negative predictive values of 95.8% and 98.7%, and test efficiencies of 77.3% and 98.0%, respectively. Compared with 74 samples that yielded growth on bacteriologic culture, the routine unstained method had concordance and misclassification rates of 39.2% and 60.8%, respectively, whereas the Wright-stained method had concordance and misclassification rates of 78.4% and 21.6%, respectively. Significant associations between each of occult blood in urine, pyuria, female sex, and lower urine specific gravity with bacteriuria detected by Wright-stained sediment examination and quantitative bacteriologic culture of urine were identified. CONCLUSIONS AND CLINICAL RELEVANCE: Examination of modified Wright-stained preparations of urine sediment appeared to be a rapid, cost effective method that significantly improved the sensitivity, specificity, positive predictive value, and test efficiency of light microscopic detection of bacteriuria, compared with that of the routine unstained method.

The agreement in isolation of Salmonella enterica IIIb 61:k:1,5,(7) from rectal swabs, faecal samples and ileo-caecal lymph nodes from sheep.

The agreements between various culturing-method combinations and specimens to detect sheep naturally infected by Salmonella enterica IIIb 61:k:1,5,(7) were tested. Rectal swabs, faecal samples and ileo-caecal lymph nodes were collected from each individual. Rectal swabs called "group I" (n = 54) were cultured directly on selective media (selenite cysteine, SC). Rectal swabs called "group II" (n = 47) were pre-incubated in buffered peptone water. The four other combinations of culturing-method and specimen (one lymph node and three faecal) in each of the two groups were cultured directly on SC. The results from all the combinations of method and specimens were compared to the result from the rectal-swab test by kappa and McNemar's chi-square. Kappas for the agreement between rectal swabs and faecal sample tests were only 0.4. The lymph-node test agreed even-more poorly, with mean kappa value -0.02. The McNemar's test revealed that the discordancies between the rectal-swab test and all of the other tests went in both directions but sometimes did show bias (directionality) in the discordancies.