Porcine respiratory disease complex: Interaction of vaccination and porcine circovirus type 2, porcine reproductive and respiratory syndrome virus, and Mycoplasma hyopneumoniae

Ballière Tindall ; W.B. Saunders 2016 The veterinary journal Vol.212 No.-

<P>Porcine respiratory disease is a multifactorial and complex disease caused by a combination of infectious pathogens, environmental stressors, differences in production systems, and various management practices; hence the name porcine respiratory disease complex (PRDC) is used. Porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), and Mycoplasma hyopneumoniae are considered to be the most important pathogens that cause PRDC. Although interactions among the three major respiratory pathogens are well documented, it is also necessary to understand the interaction between vaccines and the three major respiratory pathogens. PRRSV and M. hyopneumoniae are well known to potentiate PCV2-associated lesions; however, PRRSV and mycoplasmal vaccines can both enhance PCV2 viraemia regardless of the effects of the actual PRRSV or M. hyopneumoniae infection. On the other hand, M. hyopneumoniae potentiates the severity of pneumonia induced by PRRSV, and vaccination against M. hyopneumoniae alone is also able to decrease PRRSV viraemia and PRRSV-induced lung lesions in dually infected pigs. This review focuses on (1) interactions between PCV2, PRRSV, and M. hyopneumoniae; and (2) interactions between vaccines and the three major respiratory pathogens. (C) 2015 Elsevier Ltd. All rights reserved.</P>

Commercial porcine circovirus type 2 vaccines: Efficacy and clinical application

Ballière Tindall ; W.B. Saunders 2012 The veterinary journal Vol.194 No.2

Porcine circovirus type 2 (PCV2) is the one of the most economically important pathogens of pigs. After postweaning multisystemic wasting syndrome (PMWS) was first identified and reported in western Canada in 1991, it took 13years for the first commercial PCV2 vaccine to be used under special licence in France and Germany in 2004. Along with PMWS, PCV2 is also associated with a number of diseases and syndromes, collectively referred to as porcine circovirus-associated disease (PCVAD). Currently, five commercial vaccines are available on the international market. Commercial PCV2 vaccines were initially developed to control PMWS, but they are now also used against other PCVAD. This review focuses on (1) the types of commercial vaccines; (2) the criteria of vaccine efficacy; (3) the clinical, virological, immunological and pathological efficacy of the vaccines; and (4) the use of PCV2 vaccines against different clinical manifestations of PCVAD.

Expression of secreted and membrane-bound mucins in the airways of piglets experimentally infected with Mycoplasma hyopneumoniae

Kim, C.H.,Oh, Y.,Han, K.,Seo, H.W.,Kim, D.,Park, C.,Kang, I.,Chae, C. Ballière Tindall ; W.B. Saunders 2012 The veterinary journal Vol.192 No.1

Immunohistochemistry was used to demonstrate secreted mucins MUC2, MUC5AC and MUC5B and membrane-bound mucin MUC4 in the pulmonary bronchioles of piglets experimentally infected with Mycoplasma hyopneumoniae. Conventional status, Landrace-Duroc cross-bred piglets, 13days of age, were randomised to two groups. One group (n=20) was infected by the intra-tracheal route with the SNU98703 strain of M. hyopneumoniae, and a group of 12 animals acted as uninfected controls. Five infected and three uninfected piglets were euthanased on the day of infection and at 7, 21, and 35days post-inoculation (PI). Membrane-bound MUC4 and secreted MUC5AC were the predominant mucins produced in the bronchioles of the piglets in response to M. hyopneumoniae infection, but by day 35 PI, all labelled mucins had returned to pre-infection levels, contemporaneous with reduced pulmonary lesion scores. The increased mucin production may result from direct stimulation of the epithelium by mycoplasmal infection, or may arise indirectly following M. hyopneumoniae-induced ciliostasis.

The pharmacokinetics of the β₂-adrenoceptor agonist, tulobuterol, in Beagle dogs following transdermal and intravenous administration

Kim, J.H.,Kim, T.H.,Park, H.J.,Choi, Y.J.,Kang, J.H.,Song, K.H.,Koo, T.S.,Seo, K.W. Ballière Tindall ; W.B. Saunders 2016 The veterinary journal Vol.208 No.-

<P>Tulobuterol is a beta(2)-adrenergic agonist that was the first bronchodilator approved as a transdermal patch for humans. Previous studies have examined the pharmacokinetics of tulobuterol in humans but not in the veterinary species. In this study, the pharmacokinetics of tulobuterol was examined in healthy Beagle dogs after transdermal and intravenous administration. The C-max was 2.09 ng/mL at 16.0 h for a 0.2 mg/kg patch and 4.85 ng/mL at 13.6 h for a 0.4 mg/kg patch. The effective blood level in humans is 1-3 ng/mL, a concentration achieved using the 0.2 mg/kg patch in dogs. In conclusion, application of a 0.2 mg/kg tulobuterol patch to healthy dogs led to an apparently effective blood concentration for 24 h. (C) 2015 Elsevier Ltd. All rights reserved.</P>

Clinical and microbiological effects of a subantimicrobial dose of oral doxycycline on periodontitis in dogs

Kim, S.E.,Hwang, S.Y.,Jeong, M.,Lee, Y.,Lee, E.R.,Park, Y.W.,Ahn, J.S.,Kim, S.,Seo, K. Ballière Tindall ; W.B. Saunders 2016 The veterinary journal Vol.208 No.-

<P>Doxycycline is regarded as an effective treatment for periodontal inflammation. In humans, it has been shown that the long-term administration of a subantimicrobial dose of doxycycline (SDD) does not induce antimicrobial effects on the subgingival microflora and furthermore does not affect antimicrobial susceptibility. The present study was designed to evaluate the influence of oral administration of SDD on normal periodontal microflora and antimicrobial susceptibility in dogs. Experimental periodontitis was induced in 12 experimental dogs using a silk and wire-twisted ligature for 60 days. After the periodontitis induction period, the ligature was removed, and dental cleaning (subgingival and supragingival ultrasonic scaling) was performed. The dogs were randomly assigned to one of two groups: an SDD group with six dogs receiving 2 mg/kg PO once daily and a control group with six dogs receiving a placebo. At weeks 0, 4 and 8, clinical periodontal parameters were evaluated. After the clinical assessments, sub gingival plaque was sampled and then cultured in an anaerobic system for one week, and the total anaerobes, Porphyromonas spp., Bacteroides spp. and Pasteurella spp. counts were investigated. Using the agar dilution method, the minimum bactericidal concentration of doxycycline was evaluated and the resistance for doxycycline was monitored during this experimental phase. The clinical periodontal status of the SDD group was significantly improved compared to the control group (P < 0.05). Bacterial counts were not significantly different between the two experimental groups (P > 0.05), and antibacterial resistance was not established in the SDD group during the experimental periods (P < 0.05). These results suggest that the once daily oral regimen of 2 mg/kg of doxycycline could serve as a SDD in dogs. (C) 2015 Elsevier Ltd. All rights reserved.</P>

Prevalence and risk factors of Staphylococcus spp. carriage among dogs and their owners: A cross-sectional study

Han, J.I.,Yang, C.H.,Park, H.M. Ballière Tindall ; W.B. Saunders 2016 The veterinary journal Vol.212 No.-

<P>This study investigated colonization and association of staphylococci between healthy dogs and their owners. In a cross-sectional study, nasal carriage and antibiotic susceptibility of isolated staphylococci were determined for 119 dogs and 107 owners. Relatedness of the Staphylococcus isolates in dogs and their owners was investigated using antibiograms, toxin profiles, and genotyping by pulsed-field gel electrophoresis (PFGE), multilocus sequence type, and spa typing. Risk factors for carriage of methicillin-resistant staphylococci in dogs were also evaluated. Staphylococcus spp. were isolated from 65 (60.7%) owners and 44 (37.0%) dogs. The following species were isolated, listed in order of decreasing frequency: S. epidermidis, S. pseudintermedius, S. aureus, S. scheiferi subsp. coagulans, S. haemolyticus, S. sciuri, S. saprophyticus and S. warneri. S. pseudintermedius (65.9%) was the major isolate in dogs while S. epidermidis (81.5%) was the major type in owners. Among the isolates, 71.6% were methicillin resistant (MR) and 95.4% of the isolates demonstrated multi-drug resistance regardless of the origin. Only one dog-owner pair shared the same Staphylococcus spp. (S. pseudintermedius); however, the organisms were of different PFGE subtypes and exhibited different antibiotic resistance and toxin profiles while both isolates displayed same sequence type (ST365). While the dog-origin isolate showed spa type t02, the owner-origin isolate was negative to PCRs targeting spa gene sequence. Risk factor analysis showed that the presence of cohabitant animals was correlated with the nasal carriage of MR staphylococci in dogs. The cumulative data indicated that animal- and owner-origin staphylococci have various subtypes with high prevalence of MR; however, the bacteria are not shared between healthy dogs and their owners. (C) 2015 Elsevier Ltd. All rights reserved.</P>

Real-time PCR for differentiation of F4 (K88) variants (F4ab, F4ac, F4ad) of enterotoxigenic Escherichiacoli from diarrhoeic piglets

Byun, J.W.,Jung, B.Y.,Kim, H.Y.,Fairbrother, J.M.,Lee, W.K. Ballière Tindall ; W.B. Saunders 2012 The veterinary journal Vol.193 No.2

<P>A one-step real-time PCR using one set of oligonucleotide primers and three probes was developed for differentiation of F4 (K88) variants (F4ab, F4ac, F4ad) of enterotoxigenic Escherichia coli (ETEC) from diarrhoeic pigs. The limits of detection of F4ab, F4ac and F4ad in broth dilution were 10(6), 10(5) and 10(4) colony forming units (CFU)/mL, respectively. In faecal samples spiked with E. coli, the limits of detection of F4ab, F4ac and F4ad were 10(6), 10(6) and 10(4) CFU/g faeces, respectively, without enrichment and 10(3), 10(2) and 10(2) CFU/g faeces following enrichment. In 42 ETEC field isolates from pigs in Korea encoding the F4 gene, all were identified as the F4ac variant. (C) 2012 Elsevier Ltd. All rights reserved.</P>

Correlation of Foxp3 positive regulatory T cells with prognostic factors in canine mammary carcinomas

Kim, J.H.,Hur, J.H.,Lee, S.M.,Im, K.S.,Kim, N.H.,Sur, J.H. Ballière Tindall ; W.B. Saunders 2012 The veterinary journal Vol.193 No.1

Regulatory T cells (Treg) cells play a crucial role in tumor progression by suppressing anti-tumor immunity, but are not well-documented in veterinary oncology. To identify the characteristics of Treg cells in tumor microenvironments, the numbers of Treg cells were analyzed and compared with histological prognostic factors and molecular biomarkers in canine mammary carcinoma (MC) tissues (n=37). Abundant Treg cells were associated with high histological grade and lymphatic invasion. The numbers of Treg cells infiltrating intratumoral areas markedly increased in tumors with poor prognostic factors, such as high histological grade, lymphatic invasion, and necrosis. These findings suggest that Treg cells play a role in canine MC progression. Furthermore, Treg cell numbers in intratumoral compartments may provide a potential prognostic factor when assessing canine MCs, which may in turn lead to the development of new immunologic therapeutics.