Aeromonas hydrophila is a facultative anaerobic gram-negative bacterium regarded as an opportunistic pathogen in animals. A 17-year-old female crab-eating macaque (Macaca fascicularis) died after ...experiencing anorexia and depression for several days. The carcass was severely emaciated, and the sternum was exposed under subcutaneous lesions in the thorax. Many abnormal pathological lesions were found, including tracheal inflammation, pulmonary inflammatory emphysema, yellowish discoloration of the liver, enlargement of the gall bladder, necrosis of the heart, congested bilateral kidneys, and enlargement of the adrenal glands. The stomach was empty, mucosal ulcerations were found, and the duodenum was congested. Giemsa staining revealed rod-shaped organisms in the whole blood smear and major organs, which were identified as A. hydrophila. The animal had experienced stress, and decreased immune system function possibly contributed to the infection.
Members of the genus Coxiella can be transmitted from ticks to humans during contact with animals; Coxiella may thus spread from the infected horses or ticks to humans. In this study, the presence of ...Coxiella burnetii and Coxiella-like endosymbionts (CLE) in ticks found on infested horses was determined using PCR and genotyping. A total of 213 ticks were randomly collected from 51 horses (4-5 ticks per horse) raised on Jeju Island, Korea, between 2009 and 2013. All ticks were morphologically identified as adult Haemaphysalis longicornis, a predominant tick species widespread in Korea. Based on the results of nested PCR and 16S rRNA sequencing, CLE were detected in 121 (52.4%, 95% CI: 45.9-58.8) ticks. CLE 16S rRNA sequences from 9 randomly selected ticks were 100% identical. Phylogenetic analysis showed that these 9 sequences were highly similar (97.9-100%) to the sequences of clade B species, like the CLE previously described to be found in Haemaphysalis spp. This study showed that CLE are prevalent in ticks that infest horses reared on Jeju Island, and this is, to the best of our knowledge, the first study to describe CLE occurrence in ticks infesting animals reared in Korea. Because of the high prevalence of CLE in ticks found on horses, CLE transmission from ticks to other animals and humans remains a possibility. This warrants a detailed study of other hosts and regions. Considering the zoonotic potential of Coxiella, further strategic surveillance of Coxiella transmission is necessary.
We studied the prevalence of tickborne pathogens in canine ticks, South Korea, during 2010-2015. Results revealed a high prevalence of the emerging pathogen Rickettsia raoultii. Dog ticks may be ...maintenance hosts for tickborne pathogens, suggesting the need to continually evaluate the potential public health threat posed by R. raoultii-infected ticks.
A clinical case of
was reported for the first time in our previous study (2019) in a horse, a nondefinitive host. Although
is a ruminant and not a zoonotic pathogen, it is responsible for persistent ...infections in horses. In this follow-up study, the prevalence of
spp., including
, was assessed in horse blood and lung tissue samples to fully understand
spp. pathogen distribution and the potential risk factors of infection. Among 1696 samples, including 1433 blood samples from farms nationwide and 263 lung tissue samples from horse abattoirs on Jeju Island, a total of 29 samples (1.7%) tested positive for
and 31 (1.8%) samples tested positive for
, as determined by 16S rRNA nucleotide sequencing and restriction fragment length polymorphism. This study is the first to detect
infection in horse lung tissue samples. Further studies are needed to clarify the comparison of sample types within cohorts. Although the clinical significance of
infection was not evaluated in this study, our results emphasize the need to clarify the host tropism and genetic divergence of
to enable the development of effective prevention and control measures through broad epidemiological studies.
Feral cats that are roaming outside can serve as reservoirs for zoonotic pathogens, negatively impacting public health. They may experience high levels of parasitic infection. Some gastrointestinal ...protozoa and microsporidia possessing zoonotic potential in cats include Cryptosporidium spp., Giardia duodenalis, Blastocystis sp., Enterocytozoon bieneusi, and Toxoplasma gondii. Here, we show the infection rates and risk factors of intestinal protozoa and microsporidia detected from shelter cats on Jeju Island in South Korea in 2020. Among 158 cats, we detected genes for five internal protozoa and microsporidia, namely, Cryptosporidium felis (0.6%), G. duodenalis (3.8%), Blastocystis sp. (0.6%), E. bieneusi (3.8%), and T. gondii (1.3%). Furthermore, 16 cats (10.1%) were PCR-positive for at least one protozoan or microsporidium. To our knowledge, this study is the first to describe the existence of C. felis, G. duodenalis assemblage F, Blastocystis sp. ST4 subtype, and E. bieneusi genotype Peru11 in cats in South Korea. Despite the small number of positive samples, this study expands our understanding of the incidence of zoonotic gastrointestinal protozoa and microsporidia in shelter cats and genetically characterizes the isolates found in the infected animals. Moreover, these findings emphasize the need for a better control strategy on protozoa and microsporidia in cats, tailored to their individual needs, to protect animal and public health.
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•Genotyping of A. phagocytophilum (AP) and A. phagocytophilum-like (APL) strains.•Sixteen AP and 20 APL were detected in 764 cattle by 16S rRNA sequencing and RFLP assay.•The APL ...strains were more divergent in the groEL gene than in the 16S rRNA gene.•Amplification of the groEL and msp2 gene was unsuccessful in AP.•First detection of AP and APL in Korean cattle and possible circulation of new APL.
Anaplasma phagocytophilum is the causative agent of human granulocytic anaplasmosis and tick-borne fever in domestic ruminants. Differential diagnosis of zoonotic and pathogenic tick-borne diseases like granulocytic anaplasmosis is important for the efficient implementation of control programs. Thus, the differentiation of pathogenic A. phagocytophilum from non-pathogenic A. phagocytophilum-like (APL) Anaplasma spp. is essential. Recent molecular analyses of APL revealed its distinct phylogenetic position from A. phagocytophilum. This study was conducted to detect A. phagocytophilum and genetically related strains in 764 cattle in South Korea using PCR and restriction fragment length polymorphism assays. APL clade A and A. phagocytophilum were identified in 20 (2.6%) and 16 (2.1%) cattle, respectively, with 16 cattle (2.1%) displaying co-infection. The 16S rRNA sequences of APL clade A were similar (98.3–99.9%) to those clustered in the APL clade A from eastern Asia. The A. phagocytophilum 16S rRNA sequence shared 98.6–100% identity to those of the A. phagocytophilum group. We used PCR to amplify the groEL and msp2 genes from the 20 samples positive for the 16S rRNA gene and found that 16 were positive for the groEL sequences in the APL clade A, which showed identity (82.8–84.4%) to those clustered in the APL clade A from Japan. Amplification of msp2 was unsuccessful. The co-infection results suggested sequence diversity in Anaplasma spp. Till date, both A. phagocytophilum and APL have been reported to be distributed separately in several animals throughout South Korea. This report is the first co-detection of A. phagocytophilum and APL in Korean cattle using molecular methods. Further studies are needed to provide additional molecular background and trace the evolutionary tree of Anaplasma species in animals and ticks.
•Differential identification of Anaplasma spp. in 1219 South Korean cattle by PCR and RFLP.•Anaplasma bovis and A. capra were detected in 1.0% and 0.4% using 16S rRNA and multilocus genes.•This study ...suggests the potential of cattle to serve as reservoirs of A. capra.•The occurrence of a new emerging A. capra strain with public health and veterinary significance in Korean cattle.
Bovine anaplasmosis is a tick-borne, infectious, non-contagious disease caused by Anaplasma marginale, A. centrale, A. bovis, and zoonotic A. phagocytophilum. Recently, Anaplasma capra detected in goats was identified as a novel zoonotic pathogen. To determine whether A. capra can infect bovines, we used PCR to differentially diagnose Anaplasma spp. in 1219 South Korean cattle by performing multilocus gene typing and restriction fragment length polymorphism (RFLP). Nucleotide sequencing and phylogenetic analysis detected the 16S rRNA gene of A. bovis and four genes from A. capra in 12 (1.0%) and five (0.4%) cattle, respectively. Supplementary discrimination between A. bovis and A. capra was accomplished by RFLP. The 16S rRNA, msp4, groEL, and gltA genes of A. capra identified in this study had much lower degrees of identity to those in A. centrale and other Anaplasma spp. A. phagocytophilum was not detected in any of the tested cattle. Although the prevalence was low, this study suggests the potential of cattle to serve as reservoirs of A. capra. Thus, further studies are needed to clarify the pathogenesis of A. capra in cattle and its possible involvement in transmission to humans.
Toxoplasmosis is a major public health concern, with raw or undercooked meat being the primary source of human infection. Knowledge regarding the molecular epidemiology of Toxoplasma gondii in cattle ...destined for human consumption in Korea is lacking. The present study aimed to genetically characterize the infectious strains of T. gondii. Overall, 455 cattle blood samples from 84 farms in the Gyeongnam-do (Province) were randomly collected in 2017. Nested PCR analysis revealed that only 3 (0.7%) samples were infected with T. gondii. The B1 gene sequence of T. gondii was observed to be similar (97.3-99.6%) to that of other T. gondii isolates. This is the first study to perform the molecular detection of T. gondii in cattle in Korea. Although the prevalence of infection was low, our findings suggest that cattle present a potential public health issue. It may be crucial to recognize the importance of T. gondii infection in cattle meat.
Functional microbiome development has steadily increased; with this, the viability of microbial strains must be maintained not only after the manufacturing process but also at the time of ...consumption. Survival is threatened by various unavoidable factors during freeze-drying and shelf storage. Here, the aim was to optimize the manufacturing process of the functional strain
Lactiplantibacillus plantarum
IDCC 3501 after freeze-drying and storage. Explosive growth was achieved using a medium composition with two nitrogen sources and a mineral, and growth was drastically improved by neutralizing the medium pH during the culture of
L. plantarum
IDCC 3501. Culture optimization involved a smaller cell size, leading to less intracellular free water. Moreover, when maltodextrin (MD) powder was directly added to the harvested cells, some intracellular free water was extracted from the bacterial cells, resulting in a dramatic increase in the viability of
L. plantarum
IDCC 3501 after freeze-drying and subsequent storage. Furthermore, MD enhanced survival in a dose-dependent manner. Bacterial survival was correlated with lysozyme tolerance; therefore, the positive result might have been caused by the osmotic dehydration of intracellular free water, which would potentially damage the bacterial cells via ice crystallization and/or a phase transition during freeze-drying. These critical factors of
L. plantarum
IDCC 3501 processing provide perspectives on survival issues for manufacturing microbiome strains.
Key points
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Culture conditions for probiotic bacteria were optimized for high growth yield.
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Osmotic dehydration improved bacterial survival after manufacturing and shelf storage.
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Reduction in intracellular free water content is crucial for intact survival.
Two hemoplasma species, Mycoplasma suis and M. parvum, previously known as Eperythrozoon suis and E. parvum, respectively, have been identified in pigs. Swine hemoplasmosis is a global problem, and ...M. suis infection results in economic losses to pig producers worldwide. This study investigated the frequency and distribution of hemotropic mycoplasmas in pig farms of Korea. As hemoplasmas can be transmitted by ticks, we also analyzed the presence of the tick-borne pathogens Anaplasma spp. and Borrelia spp.
We screened 1867 samples from 464 pig farms located in four regions of Korea over the period from 2014 to 2018. PCR-positive samples were further analyzed by nucleotide sequencing and phylogenetic analysis of pathogen-specific markers for species identification.
Of the 1867 pigs evaluated in the study, three (0.2%), 51 (2.7%), and one (0.1%) were found to be infected with M. suis, M. parvum, and the novel hemotropic M. haemosuis, respectively; Anaplasma spp. and Borrelia spp. were not detected. The 16S rRNA sequences of M. suis, M. parvum, and the novel hemotropic M. haemosuis were highly similar (99.3-100%, 99.6-100%, and 99.6-100%, respectively) to those of Mycoplasma spp. isolated from other countries. To the best of our knowledge, this is the first nationwide, large-scale study of the molecular detection of Mycoplasma spp. in domestic pigs in Korea.
Our results indicate that Mycoplasma infections are widespread in Korean domestic pigs, and that continuous monitoring and control strategies are required to prevent the spread of hemoplasmas, which, in addition to causing economic losses in the pig industry, pose a potential threat to public health. As transmission routes of hemoplasmas remain unelucidated, additional epidemiological studies are recommended to identify reservoirs and vectors of Mycoplasma spp. in Korea.
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