We investigated the distribution of Cryptosporidium in pigs in Japan by immunofluorescence staining of fecal samples and characterization of isolates by multilocus sequencing. The 344 animals sampled on eight farms included pre-weaned piglets (<1 month old; n = 55), weaned piglets (1-2 months old; n = 65), finished pigs (2-4 months old, n = 105) and of 4-6 months old (n = 67), sows (n = 36), and boars (n = 16). Average prevalence of Cryptosporidium on farms was 32.6%, ranging from 4.9 to 58.1%, decreasing with animal age (prevalences of <1 month old, 1-2 months old, 2-4 months old, 4-6 months old, sows, and boars were 27.3, 47.7, 41.9, 22.4, 11.1, 18.8%, respectively). Piglets (<1 and 1-2 months old) showing signs of diarrhea shed relatively more oocysts (5.28 in average log scale of oocysts per gram) in feces than piglets with normal or loose stools (those of 4.90). Thirty seven successful sequencing of the 18S ribosomal RNA gene among 62 examined samples revealed that all of the identified isolates were Cryptosporidium suis or Cryptosporidium scrofarum, which are generally specific to pigs, and that other species, such as zoonotic Cryptosporidium parvum, were absent. Interestingly, C. suis was frequently found in piglets younger than 2 months old, while C. scrofarum infection was more prevalent in older pigs which also showed increased prevalence of mixed C. suis and C. scrofarum infections. Sequencing of actin gene loci revealed the existence of variants of both Cryptosporidium species in pigs in Japan. Although the number of pigs examined in this study was relatively low, our results suggest that Cryptosporidium infection is widespread among pigs in Japan. In addition, the possibility of age-related specificity and pathogenicity in pig infections is also suggested.

P o s i t i v e 9 5 % C I ＊ Nu mb e r ( %) 9 5 % C I ＊ Nu mb e r ( %) 9 5 % C I ＊ Nu mb e r ( %)

A shiga toxin-producing Escherichia coli (STEC) O26 strain resistant to cefotaxime (CTX) and cefpodoxime (but not ceftazidime) was isolated from the faecal sample of a 17-year-old outpatient with diarrhea. The double disk synergy test, twin test, polymerase chain reaction and sequence analysis confirmed that the strain produced CTX-M-3 type extended-spectrum beta-lactamase (ESBL). Conjugation experiment results suggested that the CTX resistance in this strain was determined by an approximately 85kbp plasmid that was readily transferable to a susceptible recipient E. coli strain. This is the first report from Japan of CTX-M-3type ESBL-producing STEC O26.

studies on the induction of diarrhea by protozoa 13,26 . In this study, we investigated swine parasitism by Cryptosporidium, Giardia, Balantidium, and coccidium by calculating the number of oocysts and cysts per gram of stools in 334 pigs and analyzing the relationships between the detection rate and age group. The stool condition score was also analyzed to investigate the relationship between infection and diarrhea. Using the results of this, the first systematically classified study of swine protozoan infection, we clarified the status of Cryptosporidium and other protozoan infections and investigated their relationships with diseases. IntroductionParasitic protozoa that inhabit the gastrointestinal tracts of pigs include Cryptosporidium, Giardia, Balantidium, coccidium, Chilomastix, Entamoeba, Iodamoeba, and Tritrichomonas 16 . Of coccidium species, Eimeria scabra 6 , Isospora suis 23, and Balantidium coli 25 are known to cause diarrhea in pigs. Cryptosporidium species (C. suis, C. pig genotype II) has been reported as having weakly pathogenic results in pigs 4,20,21,27 . However, the pathogenicity of Cryptosporidium species remains unclear, and there have been only a few pathological AbstractWe surveyed the rates of internal infection of swine with gastrointestinal tract protozoa by checking the stools of 334 pigs (suckling pigs, growing pigs aged 1 to 6 months and sows or sow candidates) on 8 hog farms in Saitama, Japan from September to November 2009. Oocysts and cysts per gram of stools in all pigs were calculated. Parasite detection rates were statistically analyzed for each of the farms, age groups, and stool condition scores, and the relationship between parasitic infection and diarrhea was investigated. Cryptosporidium was detected in 79 pigs (23.7%) of all pigs checked, Giardia was found in 53 (15.9%), Balantidium in 155 (46.4%), and coccidium in 20 (6.0%). The rate of Cryptosporidium infection was higher in the 2-and 3-month-old groups (55.6 to 60.0%) than in the others (2.5 to 27.6%) (P < 0.05): oocysts per gram of stools of 10 4 to 10 5 were detected in a total of 33 suckling pigs and 2-and 3-month-old pigs, including 10 of an outdoor farm. There was a correlation between the infection rate and diarrhea in five piglets aged 1 month or younger. In addition, the number of 6-month-old pigs infected with Giardia was 40.0%, as opposed to just 5.1% (P < 0.05) of suckling pigs. Detection rates differed among farms. The Balantidium infection rate was high in pigs older than 4 months (45.0 to 78.9%), as opposed to 15.4 to 17.2% (P < 0.05) in pigs younger than 1 month.

DNA sequences encoding the GroES and GroEL proteins of Orientia tsutsugamushi were amplified by the PCR and sequenced. Pairwise alignment of full-length groES and groEL gene sequences indicated high sequence similarity (90.4-100% and 90.3-100%) in O. tsutsugamushi, suggesting that these genes are good candidates for the molecular diagnosis and phylogenetic analysis of scrub typhus. Comparisons of the 56-kD type-specific antigen (TSA) protein gene and the groES and groEL genes showed that genotypes based on the 56-kD TSA gene were not related to a cluster containing the groES and groEL genes in a dendrogram, suggesting that a gene rearrangement may be associated with homologous recombination in mites.