A sampling and estimation method for monitoring poultry red mite (Dermanyssus gallinae) infestation on caged-layer poultry farms

Background@#The poultry red mite, Dermanyssus gallinae, is a serious problem in the laying hen industry worldwide. Currently, the foremost control method for D. gallinae is the implementation of integrated pest management, the effective application of which necessitates a precise monitoring method. @*Objectives@#The aim of the study was to propose an accurate monitoring method with a reliable protocol for caged-layer poultry farms, and to suggest an objective classification for assessing D. gallinae infestation on caged-layer poultry farms according to the number of mites collected using the developed monitoring method. @*Methods@#We compared the numbers of mites collected from corrugated cardboard traps, regarding with length of sampling periods, sampling sites on cage, and sampling positions in farm buildings. The study also compared the mean numbers of mites collected by the developed method with the infestation levels using by the conventional monitoring methods in 37 caged-layer farm buildings. @*Results@#The statistical validation provided the suitable monitoring method that the traps were installed for 2 days on feed boxes at 27 sampling points which included three vertical levels across nine equally divided zones of farms. Using this monitoring method, the D. gallinae infestation level can be assessed objectively on caged-layer poultry farms. Moreover, the method is more sensitive than the conventional method in detecting very small populations of mites. @*Conclusions@#This method can be used to identify the initial stages of D. gallinae infestation in the caged-layer poultry farms, and therefore, will contribute to establishment of effective control strategies for this mite.

Molecular subtyping and antimicrobial susceptibility of Streptococcus dysgalactiae subspecies equisimilis isolates from clinically diseased pigs

Background@#Streptococcus dysgalactiae subspecies equisimilis (SDSE) acts as an etiological agent for lameness, neurological signs, and high mortality in pigs. Despite its importance in pig industries and zoonotic potential, little is known about the effects of this pathogen. @*Objectives@#This study aimed to determine the molecular characteristics and antimicrobial resistance of SDSE strains isolated from diseased pigs. @*Methods@#A total 11 SDSE isolates were obtained from diseased pigs. Bacterial identification, PCR for virulence genes, emm typing, and antimicrobial resistance genes, multilocus sequence typing, and antimicrobial susceptibility test were performed. @*Results@#Nine isolates were from piglets, and 8 showed lameness, sudden death, or neurological signs. The isolates were PCR-positive for sla (100%), sagA (100%), and scpA (45.5%), and only 1 isolate amplified the emm gene (stL2764). Eight different sequence types were detected, categorized into 2 clonal complexes and 4 singletons. All the isolates in this study were included in a small cluster, which also contained other strains derived from humans and horses. The minimum inhibitory concentrations for the tested beta-lactams were low, while those for macrolides, tetracyclines, and fluoroquinolones were relatively high. PCR analysis of the macrolide and tetracycline resistance genes demonstrated that the isolates carried erm(B) (18.2%, n = 2), mef(A/E) (9.1%, n = 1), tet(M) (18.2%, n = 2), and tet(O) (90.2%, n = 10). Two isolates presented a mutation in parC, which is associated with fluoroquinolone resistance. @*Conclusion@#This study provided insight into swine-derived SDSE, as it is related to veterinary medicine, and elucidated its zoonotic potential, in the context of molecular epidemiology and antimicrobial resistance in public health.

Pathologic and molecular characterization of Streptococcus dysgalactiae subsp. equisimilis infection in neonatal piglets

Streptococcus dysgalactiae subspecies equisimilis (SDSE) is an emerging pathogen in animals and humans. Herein, we describe two clinical swine cases of SDSE infection presenting with lameness, neurological signs, or sudden death. Pathological examination indicated suppurative arthritis, encephalitis, and multifocal abscesses in kidney and heart. The β-hemolytic colonies obtained from joint samples of each case were identified as SDSE. The two isolates had low minimum inhibitory concentrations for β-lactams, and they presented the same virulence gene profile (slo⁻/sagA⁺/pSTKP8⁺). Molecular analysis by multilocus sequence typing identified the SDSE isolates from cases 1 and 2 as sequence types 315 and 252, respectively.

Prevalence of dog erythrocyte antigen 1, determined via immunochromatography, in domestic dogs in Korea

Blood group determination in dogs is an important factor in transfusion medicine to minimize immediate or delayed adverse reactions after red blood cells transfusion in small animal clinics. Dog erythrocyte antigen (DEA) 1 is the most important blood type due to its high degree of antigenicity causing acute transfusion adverse reactions. The aim of this study was to investigate the prevalence of DEA 1 in various dog breeds in Korea. As a result of testing 592 blood samples from more than 35 dog breeds, DEA 1 blood typing for each breed showed that 57.8% of Malteses, 63.3% of Poodles, 76.2% of Mastiff-like dogs, 72.5% of Pomeranians, 47.7% of Shih Tzus, 70.3% of mixed breeds, 60.0% of Yorkshire Terriers, and 71.4% of Beagles were DEA 1-positive. Miniature Schnauzers and Jindo breeds had a significantly high prevalence (100%) of DEA 1-positive dogs compared to that in other small breed dogs. This is the first report of immunochromatography-detected DEA 1 prevalence in various domestic dog breeds. Although additional studies need clarifying the potential blood transfusion risks in domestic breed dogs with DEA 1, the results of this study may be useful when selecting a blood donor.

Prevalence of dog erythrocyte antigen 1, determined via immunochromatography, in domestic dogs in Korea / 대한수의학회지

Blood group determination in dogs is an important factor in transfusion medicine to minimize immediate or delayed adverse reactions after red blood cells transfusion in small animal clinics. Dog erythrocyte antigen (DEA) 1 is the most important blood type due to its high degree of antigenicity causing acute transfusion adverse reactions. The aim of this study was to investigate the prevalence of DEA 1 in various dog breeds in Korea. As a result of testing 592 blood samples from more than 35 dog breeds, DEA 1 blood typing for each breed showed that 57.8% of Malteses, 63.3% of Poodles, 76.2% of Mastiff-like dogs, 72.5% of Pomeranians, 47.7% of Shih Tzus, 70.3% of mixed breeds, 60.0% of Yorkshire Terriers, and 71.4% of Beagles were DEA 1-positive. Miniature Schnauzers and Jindo breeds had a significantly high prevalence (100%) of DEA 1-positive dogs compared to that in other small breed dogs. This is the first report of immunochromatography-detected DEA 1 prevalence in various domestic dog breeds. Although additional studies need clarifying the potential blood transfusion risks in domestic breed dogs with DEA 1, the results of this study may be useful when selecting a blood donor.

Comparison of transport media for the isolation and detection of Brachyspira hyodysenteriae / 대한수의학회지

Brachyspira (B.) hyodysenteriae is a causative agent of swine dysentery that is responsible for death and economic losses in the pig industry. It is imperative that clinical samples be delivered fresh for accurate diagnosis. The viability and DNA detection of B. hyodysenteriae using lab-made (phosphate buffered saline and modified tryptic soy broth) or commercial transport media (C, D, and E) were compared by culturing and real-time PCR at 4degrees C or room temperature (RT), respectively. B. hyodysenteriae grown in D (Anaerobe Systems, USA) and E (Starplex Scientific, Canada) media was viable for 4 days at 4degrees C and RT. However, B. hyodysenteriae in A, B, and C (culture swab; BD Biosciences, USA) media were not recovered after 2 days at RT. Ct values for real-time PCR at 4degrees C and RT ranged from 27.2 +/- 2.1 (C) to 29.6 +/- 0.5 (B), and 28.0 +/- 0.9 (E) to 30.2 +/- 1.5 (B), respectively. Considering the field conditions, it is important that transport media is used for specimen isolation and PCR to obtain an accurate diagnosis of swine dysentery.