Use of cefovecin in dogs and cats attending first-opinion veterinary practices in Australia.

BACKGROUND: Cefovecin is a long-acting third-generation cephalosporin commonly used in veterinary medicine. Third-generation cephalosporins are critically important antimicrobials that should only be used after culture and susceptibility testing. The authors describe the common indications for cefovecin use in dogs and cats, and the frequency of culture and susceptibility testing. MATERIALS AND METHODS: A cross-sectional study was performed using clinical records extracted from VetCompass Australia. A previously described method was used to identify records containing cefovecin. The reason for cefovecin use was annotated in situ in each consultation text. RESULTS: Over a six-month period (February and September 2018), 5180 (0.4 per cent) consultations involved cefovecin administration, of which 151 were excluded. Cats were administered cefovecin more frequently than dogs (1.9 per cent of cat consultations and 0.1 per cent of dog consultations). The most common reasons for cefovecin administration to cats were cat fight injuries and abscesses (28 per cent) and dermatitis (13 per cent). For dogs, the most common reasons for cefovecin administration were surgical prophylaxis (24 per cent) and dermatitis (19 per cent). Culture and susceptibility testing were reported in 16 cases (0.3 per cent). CONCLUSION: Cefovecin is used in many scenarios in dogs and cats where antimicrobials may be either not indicated or where an antimicrobial of lower importance to human health is recommended.

Copper sulfate and sodium selenite lipid-microencapsulation modifies ruminal microbial fermentation in a dual-flow continuous-culture system.

Undesirable interactions between trace mineral elements and ruminal contents may occur during digestion when mineral salts are supplemented. Antimicrobial effects of copper sulfate (CuSO4) may affect ruminal digestibility of nutrients when fed as a source of copper (Cu), while sodium selenite (Na2SeO3) may be reduced in the rumen to less available forms of selenium (Se). Our objective was to evaluate if protection of CuSO4 and Na2SeO3 by lipid-microencapsulation would induce changes on ruminal microbial fermentation. We used 8 fermentors in a dual-flow continuous-culture system in a 4 × 4 duplicated Latin square with a 2 × 2 factorial arrangement of treatments. Factors were CuSO4 protection (unprotected and protected by lipid-microencapsulation) and Na2SeO3 protection (unprotected and protected by lipid-microencapsulation). Treatments consisted of supplementation with 15 mg/kg of Cu and 0.3 mg/kg of Se from either unprotected or protected (lipid-microencapsulated) sources, as follows: (1) Control (unprotected CuSO4 + unprotected Na2SeO3); (2) Cu-P (protected CuSO4 + unprotected Na2SeO3); (3) Se-P (unprotected CuSO4 + protected Na2SeO3); (4) (Cu+Se)-P (protected CuSO4 + protected Na2SeO3). All diets had the same nutrient composition and fermentors were fed 106 g of dry matter/d. Each experimental period was 10 d (7 d of adaptation and 3 d for sample collections). Daily pooled samples of effluents were analyzed for pH, NH3-N, nutrient digestibility, and flows (g/d) of total N, NH3-N, nonammonia N (NAN), bacterial N, dietary N, and bacterial efficiency. Kinetics of volatile fatty acids was analyzed in samples collected daily at 0, 1, 2, 4, 6, and 8 h after feeding. Main effects of Cu protection, Se protection, and their interaction were tested for all response variables. Kinetics data were analyzed as repeated measures. Protection of Cu decreased acetate molar proportion, increased butyrate proportion, and tended to decrease acetate:propionate ratio in samples of kinetics, but did not modify nutrient digestibility. Protection of Se tended to decrease NH3-N concentration, NH3-N flow, and CP digestibility; and to increase flows of nonammonia N and dietary N. Our results indicate that protection of CuSO4 may increase butyrate concentration at expenses of acetate, while protection of Na2SeO3 tended to reduce ruminal degradation of N. Further research is needed to determine the effects of lipid-microencapsulation on intestinal absorption, tissue distribution of Cu and Se, and animal performance.

Comparison of carpet and toothbrush techniques for the detection of Microsporum canis in cats.

OBJECTIVES: The aim of this study was to evaluate the diagnostic concordance between the toothbrush and carpet techniques for the detection of Microsporum canis in cats in a field study. METHODS: Thirty-nine Persian cats from a cattery were used. Fungal culture samples from the haircoat of each cat were collected by stroking the coat with a sterile toothbrush and a 5 × 5 cm-sized sterile carpet square (n = 78 total samples). Specimens were inoculated onto Mycosel Agar and incubated at 25°C for 21 days. Both techniques were compared using the following parameters: number of plates without fungal growth, number of plates with contaminant growth and number of plates positive for dermatophytes. RESULTS: The feline population in the study cattery was 39. Thirty (77%) were symptomatic and nine (23%) asymptomatic. The diagnosis was made via carpet and toothbrush methods and 78 cultures were performed. On day 21, M canis was detected in all culture plates. No contaminant molds were observed. CONCLUSIONS AND RELEVANCE: The concordance rate between the carpet and toothbrush techniques among the 78 evaluable culture plates was 100%. Both methods are equally effective for collecting material for Mcanis culture. Additionally, both techniques are inexpensive and easy to perform in feline clinical practice.

Development and assessment of a novel ex vivo corneal culture technique involving an agarose-based dome scaffold for use as a model of in vivo corneal wound healing in dogs and rabbits.

OBJECTIVE: To develop and assess a novel ex vivo corneal culture technique involving an agarose-based dome scaffold (ABDS) for use as a model of in vivo corneal wound healing in dogs and rabbits. SAMPLE: Corneas from clinically normal dogs (paired corneas from 8 dogs and 8 single corneas) and rabbits (21 single corneas). PROCEDURES: 8 single dog corneas (DCs), 1 DC from each pair, and 10 rabbit corneas (RCs) were wounded with an excimer laser; 1 DC from each pair and 11 RCs remained unwounded. Corneas were cultured for 21 days on ABDSs (8 pairs of DCs and all RCs) or on flat-topped scaffolds (8 single DCs). The surface area of corneal fluorescein retention was measured every 6 (DCs) or 12 (RCs) hours until full corneal epithelialization was detected. Changes in corneal clarity were evaluated at 0, 7, 14, and 21 days. RESULTS: Median time to full epithelialization for wounded dog and rabbit corneas was 48 and 60 hours, respectively; among wounded DCs, time to full epithelization did not differ by scaffold type. After 21 days of culture on ABDSs, all DCs and RCs that epithelialized developed a circular, diffuse, cloud-like pattern of optical haze, whereas DCs cultured on flat-topped scaffolds developed a focal, crater-like region of optical haze. All corneas on the ABDSs maintained convex curvature throughout the study. CONCLUSIONS AND CLINICAL RELEVANCE: Wounded ex vivo DCs and RCs cultured on ABDSs reliably epithelialized, formed optical haze (consistent with in vivo wound healing), and maintained convex curvature. This culture technique may be adaptable to other species.

Comparison of two inoculation methods for Microsporum canis culture using the toothbrush sampling technique.

BACKGROUND: The fungal culture toothbrush method is a common method for obtaining material for fungal cultures to diagnose dermatophytosis. The optimal technique for inoculation onto the agar surface has not been studied. HYPOTHESIS/OBJECTIVES: To compare two inoculation techniques; the first involved pressing the toothbrush onto the plate surface (Procedure A) and the second involved pressing the toothbrush onto the agar, as well as transferring hairs and scales entrapped in the bristles. (Procedure B). The hypothesis was that transferring hairs onto the plate would increase the likelihood of obtaining positive cultures. ANIMALS: Twenty-six cattery-housed cats were sampled using the toothbrush technique. Two toothbrush samples were obtained from each cat. METHODS AND MATERIALS: The two toothbrush samples from each cat were randomized to Procedure A or B, and the investigator was blinded to inoculation technique. Cultures were performed on a medium specific for dermatophytes. The number of positive plates, and the presence and abundance of colonies of dermatophytes and contaminant moulds were compared between the two techniques. RESULTS: Twenty-one cats were culture-positive for Microsporum canis. Procedure A resulted in a significantly higher number (P < 0.01) of positive plates (20 of 21; 95%) compared with Procedure B (seven of 21; 33%). These results were due mainly to higher plate invasion by contaminant moulds, using Procedure B. CONCLUSIONS AND CLINICAL IMPORTANCE: Based upon the findings of this study, the optimum inoculation technique is to press toothbrush bristles onto agar plates to maximize growth of M. canis and minimize introduction of contaminant inoculation.

Diagnosis of Avian Mycoplasmas: A Comparison between PCR and Culture Technique.

Mycoplasma gallisepticum and Mycoplasma synoviae are the causative agents of avian mycoplasmosis in commercial poultry. Among the available tools, polymerase chain reaction (PCR) and culture are confirmatory tools for the diagnosis of mycoplasmosis after the initial serological screening of suspected birds. Overall, 181 samples were analyzed, 152 (84%) and 103 (57%) of which were found positive by PCR and culture, respectively. Further, 54 (92%) broiler samples were found positive for general avian mycoplasma. Among the total positive samples, MS positivity was as high as 72 (47%) by PCR, while it was 45 (44%) by culture. MG positivity was 23% and 25% in PCR- and culture-positive samples. MG grows more easily compared to MS. The agreement value between the tests was 67%. Overall, flock wise prevalence was not much varied. The prevalence of mycoplasmosis was higher during winter. Our study confirmed that PCR is the most sensitive and reliable tool for the diagnosis of avian mycoplasmosis in field samples.

Towards European harmonisation of contagious equine metritis diagnosis through interlaboratory trials.

The performance of culture and PCR methods routinely used to diagnose contagious equine metritis (CEM) was evaluated and compared by two interlaboratory trials involving a total of 24 European laboratories, including 22 National Reference Laboratories for CEM. Samples were swab specimens artificially contaminated with bacteria present in the genital tract of Equidae, some with and some without Taylorella equigenitalis, the causative agent of CEM, and T asinigenitalis, responsible for possible misidentification as T equigenitalis Throughout both interlaboratory trials, PCR performed better in terms of specificity and sensitivity than the culture method, supporting the assertion that PCR should be accepted for CEM diagnosis. However, the culture performance during the second interlaboratory trial was better than during the first one, suggesting that the expertise of participants improved. This reveals the advantage of regular interlaboratory trials to constantly improve the expertise of laboratories. It also shows the need to develop new culture media that are more selective and/or better geared to the metabolism of T equigenitalis in order to improve the bacteriological diagnosis of CEM.

Effect of oocyte maturation time, sperm selection method and oxygen tension on in vitro embryo development in alpacas.

We evaluated the effect of in vitro maturation time, sperm selection and oxygen tension on alpaca embryo development. In Experiment I, Cumulus Oocyte- Complexes (COCs) were obtained from abattoir ovaries and in vitro matured in TCM-199 for 24 (n = 217), 28 (215), or 32 h (223) at 38.5 °C, high humidity and 5% CO2 in air. Oocytes from 24 (n = 392), 28 (n = 456) or 32 (n = 368) h groups were in vitro fertilized with epididymal sperm and cultured in SOFaa at 38.5 °C, high humidity and 5% CO2, 5% O2 and 90% N2 for 7 days. Embryo development was evaluated on Day 2, 5 and Day 7 of in vitro culture (Day 0 = in vitro fertilization). In Experiment II, a 2 by 2-factorial design was used to determine the effect of sperm selection (Swim-up vs Percoll) and oxygen tension (20% vs 5%) during embryo culture and their interaction on embryo development. COCs were in vitro matured for 32 h at 38.5 °C and 5% CO2 in air and then in vitro inseminated with epididymal sperm processed by swim-up or Percoll. Zygotes were cultured in SOFaa + cumulus cells at 38.5 °C under 20 or 5% of O2 tension and high humidity for 7 days. A total of 235, 235, 253 and 240 oocytes were assigned to: swim-up+20 O2, swim-up+5 O2 or Percoll+20 O2, Percoll+5 O2, groups respectively. The proportion of oocytes reaching MII stage was highest after 32 h of in vitro maturation (P < 0.05). Blastocyst rate (29.1 ± 2.7%) was also highest for COCs matured for 32 h (Exp I). In Experiment II, Blastocysts rate (26.03 ± 4.7; 27.7 ± 4.3; 29.7 ± 3.8 and 27.6 ± 4.2% for swim-up+20 O2, swim-up+5 O2 or Percoll+20 O2, Percoll+5 O2, respectively) was not affected by sperm selection method (P = 0.8), oxygen tension (P = 0.9) or their interaction (P = 0.5).

Agreement between microscopic examination and bacterial culture of bile samples for detection of bactibilia in dogs and cats with hepatobiliary disease.

OBJECTIVE To evaluate the agreement between results of microscopic examination and bacterial culture of bile samples from dogs and cats with hepatobiliary disease for detection of bactibilia. DESIGN Cross-sectional study. ANIMALS 31 dogs and 21 cats with hepatobiliary disease for which subsequent microscopic examination and bacterial culture of bile samples was performed from 2004 through 2014. PROCEDURES Electronic medical records of included dogs and cats were reviewed to extract data regarding diagnosis, antimicrobials administered, and results of microscopic examination and bacterial culture of bile samples. Agreement between these 2 diagnostic tests was assessed by calculation of the Cohen κ value. RESULTS 17 (33%) dogs and cats had bactibilia identified by microscopic examination of bile samples, and 11 (21%) had bactibilia identified via bacterial culture. Agreement between these 2 tests was substantial (percentage agreement [positive and negative results], 85%; κ = 0.62; 95% confidence interval, 0.38 to 0.89) and improved to almost perfect when calculated for only animals that received no antimicrobials within 24 hours prior to sample collection (percentage agreement, 94%; κ = 0.84; 95% confidence interval, 0.61 to 1.00). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that agreement between microscopic examination and bacterial culture of bile samples for detection of bactibilia is optimized when dogs and cats are not receiving antimicrobials at the time of sample collection. Concurrent bacterial culture and microscopic examination of bile samples are recommended for all cats and dogs evaluated for hepatobiliary disease.

Assessment of two different types of sample for the early detection and isolation of thermophilic Campylobacter in broiler farms.

In order to assess the optimal method for the early detection and isolation of thermophilic Campylobacter in broilers at farm level, two types of samples were compared: caecal contents obtained by necropsy and cloacal swabs transported in charcoal Amies medium. The study was conducted in five batches of broilers from five different farms, where weekly samples (caecal contents and cloacal swabs) from 30 birds were obtained. Samples were plated onto selective agar (modified charcoal cefoperazone desoxycholate agar, mCCDA) for Campylobacter isolation. Four out of five batches were positive for Campylobacter. No marked differences in sensitivity of both sample types were observed. However, a higher percentage of positive birds were detected when cloacal swabs were used. The results show that cloacal swab samples are adequate, and in some cases even better than caecal samples for the early detection of Campylobacter in broiler flocks at farm level. Also, this sample avoids sacrificing birds to test Campylobacter, which not only allows saving time in sample collection, transportation and processing at the laboratory, but also improves bird welfare and cost of sampling.

Efeitos da redução ou substituição do soro fetal bovino por outros compostos na maturação in vitro de oócitos bovinos / Effects of reduction or replacement of fetal calf serum by other compounds during in vitro maturation of bovine oocytes

A utilização do soro fetal bovino (SFB), embora bastante disseminada na produção in vitro (PIV) de embriões bovinos, apresenta limitações por ser um meio indefinido e por causar efeitos que prejudicam a qualidade desses embriões. Por esse motivo, nos últimos anos, grande parte das pesquisas relacionadas à PIV está voltada para a substituição do SFB por outros compostos nos meios de cultura. No presente estudo, foram utilizados como compostos protéicos a albumina sérica bovina livre de ácidos graxos (BSA-FAF) e um produto comercial denominado fluido embriônico (FE) de maneira isolada ou em diferentes combinações e concentrações, com objetivo de substituir ou diminuir a concentração do SFB durante a maturação in vitro (MIV). [...] Ademais, o G3 também apresentou diminuição na taxa de maturação nuclear quando comparado ao G4. Quanto à maturação citoplasmática, nos grupos G2, G7, G6 e G3, houve redução (p<0,05) das taxas para 43,9por cento, 43,2 por cento, 43,1 por cento e 36,5 por cento, respectivamente, quando comparadas ao meio controle (G1), que permitiu a obtenção de valores médios de 62,4 por cento. Por outro lado, nos grupos G8, G4 e G5, a taxa de maturação citoplasmática não foi afetada com a redução do SFB, onde 59,3 por cento, 51,3 por cento e 50,8 por cento dos oócitos apresentaram os GC dispostos na periferia, respectivamente. Os resultados obtidos pelo teste de contrastes ortogonais complementam os obtidos na avaliação da maturação nuclear e migração de grânulos corticais, mostrando a necessidade do SFB durante a MIV, mesmo que em baixas concentrações, e a possibilidade de diminuir a sua concentração associando-o a BSA-FAF e/ou FE. Dessa forma, conclui-se que é possível reduzir a concentração de SFB no meio de MIV para até 3,5% sem prejuízo significativo aos índices de maturação nuclear e citoplasmática.

The use of fetal calf serum (FCS), although widely employed during in vitro production (IVP) of bovine embryos, has limitations. FCS is an undefined media and may have harmful effects on the quality of embryos. For this reason, in recent years, research efforts aimed at improving IVP of bovine embryos, have focused at the replacement of FCS by alternative compounds in culture media. In this study, fatty acid free bovine serum albumin (BSA-FAF) and embryonic fluid (EF) were used separately or in combination, in different concentrations, to replace or reduce the concentration of FCS during in vitro maturation (IVM). [...] Moreover, G3 also showed inferior nuclear maturation rate when compared to G4. Regarding cytoplasmic maturation, the rates were reduced to 43.9 percent, 43.2 percent, 43.1 percent and 36.5 percent in G2, G7, G6 and G3 groups, respectively, compared to the control group (G1; 62.4 percent). On the other hand, in the groups G8, G4 and G5, maturation rates were not affected by reduction of FCS, where 59.3 percent, 51.3 percent and 50.8 percent of the oocytes displayed CG arranged peripherally, respectively. The results obtained by the orthogonal contrast test are in accordance with the ones from the evaluation of the nuclear maturation and cortical granules migration. These data show the need of FCS on the MIV, even in low concentrations, and the possibility of decrease its concentration by associating it with BSA-FAF and/or EF. Therefore, we concluded that it is possible to reduce the concentration of FCS in IVM medium to a concentration of 3.5 percent without affecting nuclear and cytoplasmic maturation rates.

Comparison of bacterial culture and polymerase chain reaction (PCR) for the detection of F. tularensis subsp. holarctica in wild animals.

Detection of the zoonotic pathogen Francisella tularensis subsp. holarctica (EF tularensis) in wild animals with culture techniques as well as polymerase chain reaction were compared and discussed on the basis of the investigation of 60 animals. The samples originated from 55 European brown hares (Lepus europaeus), two red foxes (Vulpes vulpes) and one each from a wild rabbit (Oryctolagus cuniculus), a European beaver (Castor fiber), and a lemur (Lemur catta). When comparing the growth of 28 F. tularensis isolates on the cysteine blood agar and the modified Martin-Lewis-agar used in this study, cultivation was successful for 26 isolates on both media, but for two isolates only on the cysteine blood agar. Out of 43 carcasses 19 tested positive in bacteriological culture and PCR. Two culture positive samples of tonsils originating from foxes could not be confirmed by PCR, although PCR was positive in 22 samples that missed growth of F. tularensis. Comparative studies on cultural detection of E. tularensis were performed on samples of 16 hares from lung, spleen, liver and gut and in one case with a peritoneal swab. In at least one of these localizations cultivation of the pathogen was successful. Detection rate was reduced to 94% (15 of 16 hares) considering only the results of the cultures of the lungs and spleens. For a sensitive and rapid detection of F. tularensis subsp. holarctica, the PCR is a suitable method thereby avoiding hazardous multiplying of the pathogen. However, cultivation of F. tularensis is often a prerequisite for further studies on antibiotic resistance patterns of the pathogen, molecular epidemiological and pathological analyses of tularaemia.

Urinary tract infections in sows in Italy: accuracy of urinalysis and urine culture against histological findings.

In order to investigate the prevalence of urinary tract infections (UTI) in sow, lower urinary tract (LUT), kidney and urine samples were collected at slaughterhouse from 65 multiparous culled sows. Histopathology was performed on urethra, urinary bladder and -kidney sections. Urine collected by cystocentesis was analysed for physical and biochemical parameters, in addition to microscopic examination of the sediment and quantitative culture ( > 10(5) CFU/ml urine). The diagnostic accuracy of urinalysis and urine culture was calculated for the parameters that correlated with histological diagnosis: bilateral chronic lesions were found in 54 per cent of kidney samples and diffuse/multifocal lymphoplasmacytic infiltration of the submucosa in 53 per cent of the bladder and 68 per cent of the urethra samples. In 49 per cent of cases, the co-occurrence of bladder and urethra lesions was statistically significant (P < 0.009). Turbid urine (80 per cent sensitivity, 50 per cent specificity), > 5 white blood cells per high-power field (34 per cent sensitivity, 90 per cent specificity), intracellular or free bacteria (43 per cent sensitivity, 90 per cent specificity), and urine culture (49 per cent sensitivity, 97 per cent specificity) correlated with a finding of histopathological changes in the bladder. UTI appears to be common in culled sows in northern Italy. Compared with histopathology, urinalysis and urine culture showed low sensitivity but high specificity in detecting UTI.

Evaluation of a simple Theileria annulata culture protocol from experimentally infected bovine whole blood.

We have evaluated a new simple technique using whole blood from experimentally infected cattle for the isolation and cultivation of Theileria annulata. The study was carried out on 20 Holstein-Frisian bovines that had been experimentally infected with a virulent lethal dose of Theileria annulata. This technique has been compared to the classical peripheral blood monocyte isolation with Ficoll carried out on 22 experimentally infected Holstein-Friesian calves. The effectiveness of the reference technique was estimated to 86.4%, whilst the effectiveness of the new technique was 100%. Moreover, this new technique leads to time and money saving estimated to € 3.06 per sample. It decreases the contamination risks by reducing the steps of sample manipulation.

Mycobacterial disease in cats in Great Britain: I. Culture results, geographical distribution and clinical presentation of 339 cases.

This study investigated 339 cases of feline mycobacterial disease from cats with cutaneous lesions or masses found at exploratory laparotomy. Tissue samples were submitted to the Veterinary Laboratories Agency for mycobacterial culture over a 4-year period to December 2008. The study assessed which species of culturable mycobacteria were involved, where the cats lived, and their clinical presentation (physical findings, serum biochemistry, radiography, feline leukaemia virus and feline immunodeficiency virus status). Mycobacterium microti was cultured from 19%, Mycobacterium bovis 15%, Mycobacterium avium 7%, non-M avium non-tuberculous mycobacteria 6%, with no growth in 53% of samples. M microti, M bovis and M avium were found in almost mutually exclusive clusters within Great Britain (GB) (ie, M bovis in South-West England/Wales/Welsh Border, M avium in eastern England and M microti south of London and in South-West Scotland). While differences were seen in the clinical presentation and distribution of lesions caused by the different infections, these were not sufficiently different to be diagnostic. Cats commonly presented with single or multiple cutaneous lesions (74%), which were sometimes ulcerated or discharging, located most frequently on the head (54%). Lymph nodes were usually involved (47%); typically the submandibular nodes. Systemic or pulmonary signs were rarely seen (10-16%). When a cat is suspected of having mycobacteriosis, accurate identification of the species involved helps to determine appropriate action. Our findings show that knowing the cat's geographic location can be helpful, while the nature of the clinical presentation is less useful. Most cases of feline mycobacterial disease in GB are cutaneous.

Viral replication in excised fin tissues (VREFT) corresponds with prior exposure of Pacific herring, Clupea pallasii (Valenciennes), to viral haemorrhagic septicaemia virus (VHSV).

Procedures for a viral replication in excised fin tissue (VREFT) assay were adapted to Pacific herring, Clupea pallasii, and optimized both to reduce processing time and to provide the greatest resolution between naïve herring and those previously exposed to viral haemorrhagic septicaemia virus (VHSV), Genogroup IVa. The optimized procedures included removal of the left pectoral fin from a euthanized fish, inoculation of the fin with >10(5) plaque-forming units (PFU) mL(-1) VHSV for 1 h, rinsing the fin in fresh medium six times to remove unadsorbed virions, incubation of the fin in fresh medium for 4 days and enumeration of the viral titre in a sample of the incubation medium by plaque assay. The optimized VREFT assay was effective at identifying the prior exposure history of laboratory-reared Pacific herring to VHSV. The geometric mean VREFT value was significantly greater (P < 0.01) among naïve herring (1.2 × 10(3) PFU mL(-1) ) than among groups that survived exposure to VHSV (1.0-2.9 × 10(2) PFU mL(-1) ); additionally, the proportion of cultures with no detectable virus was significantly greater (P = 0.0002) among fish that survived exposure to VHSV (39-47%) than among naïve fish (3.3%). The optimized VREFT assay demonstrates promise for identifying VHSV exposure history and forecasting disease potential in populations of wild Pacific herring.

Comparison of tuberculin activity using the interferon-gamma assay for the diagnosis of bovine tuberculosis.

In this study, interferon-gamma (IFN-gamma) responses in whole blood cultures stimulated with tuberculins from different sources were compared with regard to their diagnostic reliability in cattle experimentally and naturally infected with Mycobacterium bovis. The IFN-gamma responses to different concentrations of purified protein derivatives (PPDs) from M bovis and Mycobacterium avium were quantified. Significant differences (P<0.05) between sources and concentrations of PPDs used for stimulation were detected, indicating a need for standardisation of PPDs used in the IFN-gamma assay. Additionally, a tool named'relative potency 30' that allows rapid comparison of batches and sources of PPDs was defined.

Establishment of culture conditions for survival of Histomonas meleagridis in transit.

Fresh ceca samples from turkeys in North Carolina infected with Histomonas meleagridis were collected at necropsy, inoculated into warmed Dwyers medium, and sent by overnight courier to our laboratory at The University of Georgia. Further incubation at 40 C yielded positive cultures from all four samples. PCR and DNA sequencing confirmed the presence of H. meleagridis. To further establish conditions for survival in transit, we infected turkeys with H. meleagridis, euthanatized the birds 10 days postinfection, and allowed carcasses to incubate at room temperature for either 2 or 24 hr. After incubation, samples of cecal contents (0.5 g) were placed in Dwyers medium and held at 4, 25, or 30 C for 6, 18, 24, 48, 72, 96, or 120 hr, simulating holding conditions during transit. Samples were placed in a 40 C incubator at the specified times and examined daily for histomonad growth by light microscopy. Positive histomonad growth was detected from cecal samples obtained from the 2-hr incubated carcass and from cultures held at 30 C for 6, 18, 24, 48, and 72 hr. No growth was seen from cultures held at 25 or 4 C or at any temperature from the carcass allowed to incubate for 24 hr at room temperature. These results suggest that positive isolation can be made from field samples, provided that material is collected at warm temperatures and transported rapidly to the laboratory.