[Annual changes in antimicrobial susceptibility of Campylobacter jejuni and Campylobacter coli isolated from acute diarrheic patients].

Two hundred thirty-one Campylobacter were isolated from acute diarrheic patients between January 2001 and December 2005. We evaluated annual changes in identified species of Campylobacter and their susceptibilities against antibiotics. Campylobacter jejuni (219 strains; 94.8%) and Campylobacter coli (12 strains; 5.2%) were identified to the species. Susceptibilities to four antimicrobial agents, minocycline (MINO), levofloxacin (LVFX), erythromycin (EM) and clindamycin (CLDM) were examined. The resistant rates of four antimicrobial agents in C. coli were significantly higher than that in C. jejuni. The susceptibility of C. jejuni to LVFX was variable, and MICs gave a bimodal distribution. The resistant rate against EM was estimated to be 9.2% in C. jejuni, 66.7% in C. coli. Moreover, young people ranging from 19 to 24 years old were predominant (47.7%) among the Campylobacter enteritis patients.

Regional variation in the prevalence of extended-spectrum beta-lactamase-producing clinical isolates in the Asia-Pacific region (SENTRY 1998-2002).

We examined the prevalence of extended-spectrum beta-lactamase (ESBL)-producing strains of Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Proteus mirabilis, Citrobacter koseri, and Salmonella spp. that were isolated as part of the SENTRY Asia-Pacific Surveillance Program between 1998 and 2002. During the study period, a total of 6,388 strains were gathered from 17 medical centers in 7 countries and examined for ESBL production and hyperproduction of K. oxytoca chromosomal K1 beta-lactamase enzyme. High rates of confirmed ESBL-producing isolates were found in K. pneumoniae strains from Singapore (35.6%), followed by those from mainland China (30.7%), South Africa (28.1%), and the Philippines (21.9%), whereas the rates were less than 10% in Japan and Australia. ESBL-producing E. coli strains were also prominent in mainland China (24.5%), Hong Kong (14.3%), and Singapore (11.3%). ESBL-producing K. oxytoca were common in the Philippines (38.5%), Singapore (33.3%), and China (30.0%). Hyperproduction of K. oxytoca chromosomal K1 beta-lactamase enzyme was common in Australia and Japan. P. mirabilis strains from Singapore produced ESBL (17.9%) despite the low prevalence (0-8.1%) in other countries. Few ESBL-producing C. koseri and Salmonella spp. strains were found in Japan, Singapore, Taiwan, and South Africa. Although there was variation among countries in substrate preference, ceftazidime was more likely to detect presumptive ESBL phenotype in K. pneumoniae and aztreonam more likely in E. coli, whereas ceftriaxone was the best substrate for the confirmation of ESBL production. ESBL-producing strains showed high levels of co-resistance to aminoglycosides, tetracycline, trimethoprim-sulfamethoxazole, and ciprofloxacin. Imipenem retained activity against all ESBL-producing strains. Organisms expressing ESBLs are widely distributed in the Asia-Pacific region, although prevalence rates vary significantly.

Evaluation of the contemporary occurrence rates of metallo-beta-lactamases in multidrug-resistant Gram-negative bacilli in Japan: report from the SENTRY Antimicrobial Surveillance Program (1998-2002).

Metallo-beta-lactamases (M beta L) were initially characterized in Japan, usually of the IMP-type, and found in Pseudomonas aeruginosa (PSA), Acinetobacter spp. (ACB), or Serratia marcescens (SM). The number of M beta L types has increased worldwide, but geographic dissemination within Japan has appeared limited. This study compares baseline levels of M beta L resistance from two 22-center studies (1996-1997) to the longitudinal sample (3 sites) of Japanese isolates from the SENTRY Antimicrobial Surveillance Program (1998-2002). All minimal inhibitory concentration results were determined by reference methods. A total of 26.8% PSA, 3.4% ACB, and 3.1% Enterobacteriaceae (enterobacters and SM) with resistance to monitored carbapenems (CARB) (minimal inhibitory concentration, > or =8 microg/mL) were screened for M beta L production by disk approximation tests (EDTA and 2-MPA inhibitors), CARB hydrolysis by enzyme extracts, and selected PCR primers for known M beta L types. All M beta L-positive strains (10) were sequenced to determine enzyme identification. Clonality in each center was determined by automated ribotyping and PFGE. The CARB susceptibility rates in PSA decreased (80.7% to 62.0%) over the monitored interval (1998-2002), but varied by medical center location. Among CARB-resistant isolates, 10.8% were attributed to M beta L strains (1.1% of all PSA tested). M beta L identification showed the following: five PSA (three IMP-1, two IMP-2), four SM (one IMP-1, two IMP-1 + OXA-1, and one IMP-11). Also a single ACB had an IMP-1. Eight of 10 M beta L isolations occurred between 2000 and 2002; four occurred in 2002. BRL42715, an AMP-C inhibitor, confirmed AMP-C-mediated resistance in 87.3% of PSA, and outer membrane protein changes were also discovered by membrane studies. Prior results (22 sites, 1997-1998) showed CARB resistance at 22.4-25.6% and 0.5-0.9% M beta Ls (IMP-1) overall; it was slightly elevated in this SENTRY Program sample. In conclusion, M beta L-producing strains from several species persist in Japan, but represent a distinct minority of all CARB-resistant strains (1998-2002). Although M beta L rates appear generally stable in Japan, continued surveillance for these mechanisms seems to be a prudent practice, because of the mobility of the genetic determinants and the emergence of novel enzyme types, especially among the Enterobacteriaceae.

Clinical usefulness of multiplex PCR lateral flow in MRSA detection: a novel, rapid genetic testing method.

Methicillin-resistant Staphylococcus aureus (MRSA) with exogenous cassette DNA containing the methicillin-resistant gene mecA (SCCmec) poses a problem as a drug-resistant bacterium responsible for hospital- and community-acquired infections. The frequency of MRSA detection has recently been increasing rapidly in Japan, and SCCmec has also been classified more diversely into types I-V. A rapid test is essential for early diagnosis and treatment of MRSA infections, but detection by conventional methods requires at least two days. The newly developed multiplex PCR lateral flow method allows specific amplification of femA to detect S. aureus, mecA to detect SCCmec, and kdpC to detect SCCmec type II; moreover, PCR products can be evaluated visually in about 3 h. In the present study, we developed a PCR lateral flow method for MRSA using this method and investigated its clinical usefulness in the detection of MRSA. The results showed a diagnostic concordance rate of 91.7% for MRSA and methicillin-susceptible S. aureus between bacteriological examination and PCR lateral flow, and a high level of specificity in PCR lateral flow. In addition, a higher detection rate for S. aureus using the same sample was observed for PCR lateral flow (70.2%) than for bacteriological tests (48.6%). The above results show that PCR lateral flow for MRSA detection has high sensitivity, specificity, and speed, and its clinical application as a method for early diagnosis of MRSA infections appears to be feasible.

A case of giardiasis expressing severe systemic symptoms and marked hypereosinophilia.

An 88-year-old Japanese woman was referred to our hospital due to a one-month history of face edema, aphagia, shortness of breath, and skin rush over almost her entire skin. She had no abdominal symptoms. Her peripheral blood count showed a white blood cell (WBC) count of 27.1x10(9)/L with 82.1% eosinophils. Serum non-specific Immunoglobulin E was within a normal range. Soluble interleukin-2 receptor was elevated to 4200U/mL. At first, her eosinophil count was so high that we suspected she had an eosinophilic leukemia or hypereosinophilic syndrome. After admission, cysts of Giardia duodenalis (G. duodenalis) were detected in the patient's feces by microscopic analysis, then she was diagnosed with giardiasis, and 750mg per day of metronidazole was administered for seven days. Her WBC count decreased to 6.0x10(9)/L with 10% eosinophils, and her systemic symptoms improved. At that time her serum IL-5 was within a normal range. A few months later, the patient again complained of skin rush, and G. duodenalis was once again found in her feces. Her serum IL-5 was elevated to 751pg/mL. Metronidazole was administered for two weeks, and her eosinophil count decreased. G. duodenalis is a protozoan parasite, and it is one of the most common waterborne transmission gastrointestinal parasites in the world. G. duodenalis rarely causes hypereosinophilia. To our knowledge, this is the first case report of giardiasis with extreme hypereosinophilia and severe systemic symptoms.