Isolation and Characterization of Toxoplasma gondii Genotypes from Goats at an Abattoir in Okinawa

SUMMARY: Toxoplasma gondii genotypes were isolated and characterized from cephalic muscle samples collected from 24 goats slaughtered at an abattoir in Okinawa between 2008 and 2009. Of the 24 samples assayed using latex agglutination, 18 were seropositive, 2 were pseudo-positive, and 4 were seronegative against T. gondii antibodies. The samples were then inoculated into laboratory mice to isolate the parasite. Among the isolated samples, 13 (72.2z of the 18 seropositive strains in the latex agglutination assay) were seropositive, 1 (50z) was pseudo-positive, and none were seronegative. However, after being frozen and stored at -209 C, all samples were found to be T. gondii-free. Of the 14 isolates of the GRA6 genotype, 6 were of type I, 7 were of type II, and 1 was of type III; the genotype distribution ratio was similar to that of T. gondii strains isolated from locally raised pigs. Moreover, no sulfonamide-tolerant dhps gene mutant of T. gondii was detected

Laboratory diagnostic, epidemiological, and clinical characteristics of human leptospirosis in Okinawa Prefecture, Japan, 2003-2020.

BackgroundLeptospirosis is considered an endemic disease among agricultural workers in Okinawa Prefecture, which is the southernmost part of Japan and has a subtropical climate, but data on the current status and trend of this disease are scarce.Methodology/principal findingsWe conducted a retrospective study of clinically suspected leptospirosis patients whose sample and information were sent to the Okinawa Prefectural Institute of Health and Environment from November 2003 to December 2020. Laboratory diagnosis was established using culture, nested polymerase chain reaction (PCR), and/or microscopic agglutination test (MAT) with blood, cerebrospinal fluid, and/or urine samples. Statistical analyses were performed to compare the epidemiological information, clinical features, and sensitivities of diagnostic methods among laboratory-confirmed cases. Serogroups and the species of Leptospira isolates were determined by MAT using 13 antisera and flaB sequencing. A total of 531 clinically suspected patients were recruited, among whom 246 (46.3%) were laboratory confirmed to have leptospirosis. Among the confirmed cases, patients aged 20-29 years (22.4%) and male patients (85.7%) were the most common. The most common estimated sources of infection were recreation (44.5%) and labor (27.8%) in rivers. Approximately half of the isolates were of the L. interrogans serogroup Hebdomadis. The main clinical symptoms were fever (97.1%), myalgia (56.3%), and conjunctival hyperemia (52.2%). Headache occurred significantly more often in patients with Hebdomadis serogroup infections than those with other serogroup infections. The sensitivities of culture and PCR exceeded 65% during the first 6 days, while the sensitivity of MAT surpassed that of culture and PCR in the second week after onset. PCR using blood samples was a preferable method for the early diagnosis of leptospirosis.Conclusions/significanceThe results of this study will support clinicians in the diagnosis and treatment of undifferentiated febrile patients in Okinawa Prefecture as well as patients returning from Okinawa Prefecture

Childhood leptospirosis in an industrialized country: Population-based study in Okinawa, Japan.

Leptospirosis is considered underdiagnosed because of its nonspecific presentation and lack of proper understanding of its epidemiology. Early diagnosis and treatment are crucial. However, few data are available on confirmed leptospirosis cases in children in industrialized countries. We therefore aimed to describe epidemiologic and clinical characteristics of laboratory-confirmed childhood leptospirosis in Okinawa, Japan. We reviewed the national surveillance data of pediatric leptospirosis in Okinawa, Japan from January 2003 through December 2015. The database included all of laboratory-confirmed leptospirosis diagnosed at the only central laboratory for leptospirosis in the region. There were 44 children (0-20 years of age) with laboratory-confirmed leptospirosis. Of these, 90% were male, 91% were 10-20 years of age, and 96% of cases occurred in August and September. The number of laboratory-confirmed patients ranged from 0 to 11 per year (mean: 3.3 per year), and the estimated annual rate was 1.0 per 100,000 pediatric populations. In all cases, the presumed infection route was recreational exposure to river water. Commonly observed manifestations include fever (95%), myalgia (52%), and conjunctival suffusion (52%). Childhood leptospirosis in Okinawa, Japan occurred predominantly in teenage boys after freshwater exposure in summer, and most patients had characteristic conjunctival suffusion. Cohort studies would be helpful to better understand more detailed clinical manifestations in association with prognosis

Molecular and biological analysis revealed genetic diversity and high virulence strain of Toxoplasma gondii in Japan.

Toxoplasma gondii is classified into 16 haplogroups based on a worldwide genotyping study of the parasite. However, only a few isolates from Japan were included in this analysis. To conduct more precise genotyping of T. gondii, we examined the genotypes of Japanese isolates in this study. DNA sequences of 6 loci were determined in 17 Japanese isolates and compared with those of strains of 16 haplogroups. As a result, Japanese isolates were classified into four groups. We investigated the virulence of some Japanese isolates and found a highly virulent strain in mice, comparable to that of RH strain, although this Japanese isolate was sister to strains of haplogroup 2, which show moderate virulence in mice. We further investigated whether this high virulence isolate had different virulence mechanism and strategy to adapt to Japanese host from other strains by comparing the virulence-related genes, ROP5, 18 and the immunomodulatory gene, ROP16 of the isolate with those of archetypical strains (GT1, ME49 and VEG). This analysis indicated the high virulence of the isolate in mice was partly explained by gene sequences of ROP5 and ROP16. These findings lead to the elucidation of biodiversity of T. gondii and have potential to optimize the diagnostic protocol

Patient characteristics (n = 44), no. (%).

<p>Patient characteristics (n = 44), no. (%).</p

Annual number of cases.

<p>Adult leptospirosis cases reported in Okinawa [<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0006294#pntd.0006294.ref005" target="_blank">5</a>] are shown for comparison.</p

Comparison between this study and Tsuha's study, no. (%).

<p>Comparison between this study and Tsuha's study, no. (%).</p