Direct rapid genetic diagnosis by RT-PCR as well as virus isolation was performed on the 122 patients with hand, foot and mouth disease (HFMD) in Osaka Prefecture in 2000, followed by molecular epidemiological analyses of the isolated viruses. MRC-5 cells showed the highest sensitivity for virus isolation, recovering 59 strains of viruses from 80 virus-positive patients. By RT-PCR using newly designed primers spanning VP4 and VP2, corresponding genome regions of coxsackievirus type A16 (CA16) and enterovirus 71 (EV71) isolates were amplified only with primers specific to respective viruses. On the other hand, none of the genomes of prototype enteroviruses of other 49 serotypes were detected with these primers. From the sequence analyses, all of the 22 isolates of CA16 belonged to the same genotype and 33 isolates of EV71 were classified into two genetic groups. The results showed that 3 different genotypes of viruses were prevailing in the epidemic of HFMD in Osaka Prefecture in 2000.

View full abstract

In June 2000, many cases with persistent cough were observed among inpatients and the staff of a ward for severely retarded. Some of them had symptoms suggestive of pertussis, such as whooping, post-tussive apnea. We performed a retrospective investigation to assess symptoms and serological findings suspicious of pertussis. There were a total of 14 cases of persistent cough over 3 weeks (4 to 9 weeks). 6 cases were inpatients and 8 were hospital staff. Of those, serological test for pertussis infection was performed in 10 cases and 6 cases were diagnosed as serologically confirmed pertussis. The other cases with persistent cough were also considered to be probable pertussis as they have had intensive contact with serologically confirmed cases. 12 cases were treated by antibiotics, but they all failed to respond.
It was suggested that Bordetella pertussis must be considered as a causal organism of persistent cough even in adults. To prevent nosocomial transmission of pertussis, droplet precautions and macrolide treatment should be provided for patients with symptoms highly suggestive of pertussis.

View full abstract

One hundred and fourteen Shigella sonnei strains obtained in 1991 to 2000 were tested for their susceptibilities to 12 antimicrobial agents. Nalidixic acid (NA) resistance was found in 2 of 15 strains (13.3%) in 1993, 2 of 8 strains (25%) in 1996, one of 5 strains (20%) in 1998, 7 of 21 strains (33.3%) in 1999 and 6 of 12 strains (50%) in 2000. The incidence of resistance to NA in S. sonnei strains increased significantly during this period. Among those 19 NA resistant strains, 11 strains were derived from patients with traveler's diarrhea and 8 strains were derived from patients who had not traveled abroad before the infection, namely domestic patients. PFGE analysis with Xba I revealed that all strains tested differentiated into two major clonal clusters, one cluster consisted of strains derived from patients who had traveled to India after 1993, and another cluster included strains derived from domestic patients.
Mechanism of NA resistance was examined by sequencing the quinolone resistance-determining region (QRDR) of gyrA gene. Among 19 NA resistant strains tested, 11 strains presented a change at Ser-83 to Leu and 7 strains presented a change at Asp-87 to Try (5 strains) or Asn (2 strains), whereas 3 NA sensitive strains had no change in the region. These findings indicated that this mutation in gyrA plays an important role in acquisition of Nalidixic-acid resistance in clinical isolates of S. sonne.

View full abstract

We surveyed the epidemiology of purulent meningitis in pediatrics for 3 years between July 1997 and June 2000 in Japan and obtained the following results. The number of cases of purulent meningitis was 428, which was equivalent to 1.1-1.7 children out of 1, 000 hospitalized those in pediatrics per year. The age-distribution for the infections was the highest under 1 year of age and it decreased as the age increased. Under 1 year of age, the highest distribution was observed in one month of age and under 1 month of age, the highest distribution was observed in 7 days of or younger ages. Haemophilus influenzae was the most common pathogen causing the infections, followed by Streptococcus pneumoniae, group B streptococcus, and Escherichia coli. Relationship betweencausing pathogens and age-distribution was as follows: group B streptococcus and E. coli were major pathogens under 4 months of age and H. influenzae and S. pneumoniae were major pathogens over 3 months of age. Susceptibility tests performed at each facility demonstrated that 25.3% of H. influenzae isolates and 38.7% of S. pneumoniae isolates were drug-resistant. Analysis of resistant genes for H. influenzae and S. pneumoniae isolates, which were stored and sent, demonstrated higher rates of resistance than those observed in susceptibility tests. These results suggest that the increase in insufficient efficacy of usual treatment with combination of ampicillin and cefotaxime is predictableagainst the infections. Therefore, the treatment for the infections should be reconsidered.

View full abstract

MRSA infection or colonization developed in eleven patients with neoplastic disease including malignant lymphoma (5 cases), soft tissue sarcoma (2 cases), acute myeloblastic leukemia (one), myelodysplastic syndrome (one), multiple myeloma (one), and mesothelioma (one) at our ward from October to December 1999. The infections were pneumonia (six cases), enteritis (three), bacteremia (one), and wound infection (one). Ten of 11 cases received antimicrobial agent (s) during one month before isolation of MRSA, suggesting selection of MRSA. Five cases improved and survived, but six cases died of infection. At the isolation of MRSA, the neutrophil count (NC) of the alive cases was 1, 500/μl or more but the NC of five cases who died was less than 1, 000/μl, especially less than 100/μl in three cases who had just received a cancer chemotherapy. Pulsed-field gel electrophoresis, performed in 9 cases, showed an identical DNA-pattern of MRSA in 7 cases, indicating a nosocomial infection. Our method to prevent spread of MRSA targeting solely the patients with MRSA infection was obviously unsatisfactory. We should target also the cases of MRSA colonization and make an effort to wash hands more vigorously. Furthermore, radical reformation such as increasing single sickrooms drastically and increasing the number of nursing staff is also required.

View full abstract

We detected the metallo-β-lactamase gene bla_IMP positive strains of the gram-negative rods (GNR) isolated in Oita Medical University Hospital between 1993 and 1999 and studied the clinical characteristics of patients infected or colonized with bla_IMP positive GNR. 25 strains (20 Pseudomonas aeruginosa and 5 Serratia marcescens) were detected and most of them were isolated from urinary samples after 1997. In the studies of antimicrobial susceptibility, some strains had sensitivity to aztreonum or imipenem although most of the strains showed multidrug resistance.
When bla_IMP positive GNR were isolated from patients, these strains were thought to have caused infection in 88% of the patients. About half of the patients were over 65 years old and had malignant diseases. Most of the patients had inserted urinary tract catheters, intratracheal tube or intravernous catheters. It was suggested that the insertion of the catheters were related to infection of bla_IMP positive GNRs. Two patients were not treated with any antibiotics before the isolation of Ham, positive GNRs although more than half of the patients were administered carbapenems and cephems. Most of strains were isolated in the same department and showed the same genotype by pulsed field gel electrophoresis.

View full abstract

We attempted to isolate TDH-producing Vibrio parahaemolyticus O3: K6 from shellfish. Asari samples were incubated with TSB supplemented with 2% (w/v) NaCl for 6h, and then the 6-h cultures were incubated with salt polymyxin broth for 18h. After the two-step enrichment, a 1ml portion of the culture was treated with magnetic beads coated with K6 antibody for immunoconcentration ofV. parahaemolyticus O3: K6. The immunoconcentrated and untreated cultures were plated onto a chromogenic agar and TCBS agar media for isolation of V. parahaemolyticus. TDH-producing V. parahaemolyticus O3: K6 was isolated from 3 out of 66 lots (4.5%) of naturally contaminated Asari. Six of 4, 265 colonies suspected as V. parahaemolyticus (0.14%) were TDH-producing V. parahaemolyticusO3: K6.

View full abstract

We have performed transtracheal aspiration (TTA) in 1, 416 patients, who were suspected to have bronchopulmonary infection, in order to collect non-contaminated specimens directly from the lower airway. The overall isolation rates in 1, 416 TTA were 68.7%for any microorganisms. Aerobes had a high incidence but many kinds of microorganisms were associated with bronchopulmonary infections.
Haemophilus influenzae was the major pathogen in patients with acute bronchitis. Streptococcus pneumoniae was the most important pathogen and mycoplasma was often isolated in patients with community-acquired pneumonia. Major pathogens of nosocomial pneumonia consisted of α-streptococcus spp., anaerobes and Pseudomonas aeruginosa. Anaerobes were isolated from transtracheal aspirates in 20 of 33 episodes of lung abscesses. H. influenzae and P. aeruginosa were the main persistent pathogens and H. influenzae, S. pneumoniae and anaerobes were important exacerbated pathogens in patients with chronic lower respiratory tract infection.
S. pneumoniae was isolated more from TTA than expectorated sputa. Oropharyngeal flora bacteria were easily isolated in the culture of expectorated sputa.
We assessed the final diagnosis or causative factor in 443 patients whom no microorganism was isolated from transtracheal aspirates. The final diagnosis was infectious diseases in 52 patients (11.7%) and non-infectious diseases in 80 patients (18.1%), respectively. The causative factor was unsuited TTA sample in 81 patients (18.3%), preceding antimicrobial chemotherapy in 95 patients (21.4%) and unknown in 135 patients (30.5%), respectively.
The pathogenesis of bronchopulmonary infections is complex and various microorganisms are associated with pathogens of bronchopulmonary infections. Therefore, we should accurately diagnose the pathogens in patients with bronchopulmonary infections. TTA is one of the useful methods that we can accurately detect the respiratory pathogens.

View full abstract

We report a patient who developed SLE during the course of diffuse panbronchiolitis (DPB) and had candidiasis later. The patient fulfilled the criteria for diagnosis of SLE after appearance of fever and general peripheral arthritis. Regarding serum virus antibody values at the time of SLE diagnosis, IgG and IgM of human Parvovirus B19 (B19) were positive by the EIA test and also by the serum PCR test. For continuously Pseudomonas aeruginozae in sputum cultures because of existing DPB, immunosuppressasnt therapy with prednisolone and mizoribine was given while suppressing proliferation of bacterial infections with antibiotics. As a result, the intensity of SLE decreased smoothly. About 1 month after beginning of the treatment, the chest X-ray revealed infiltrative densities in the lingual area of the left lobule and in S3 of the right lobule. Judging from the clinical course and various examination findings, concurrence of candidiasis was suspected. Fungal infection in this patient was progressive, so various antifungal agents were used concurrently. Futhermore, immunoglobulin therapy was supplemented while determining serum immunoglobulin levels, and doses of prednisolone and mizoribine were reduced rapidly. Afterward the patient followed a satisfactory clinical course. About 2 years later SLE recurred, aspergillosis developed concurrently and the disease progressed rapidly to its termination.
DPB itself is difficult to control and often complicated with various diseases. Therefore, immunosuppresant therapy for complications is sometimes used in addition to the treatment of DPB. More careful observations on the clinical course are necessary in dealing with this disease.

View full abstract

Eikenella corrodens is a gram-negative, facultative anaerobic rod that frequently exists as part of normal human flora in the upper respiratory tract and gastrointestinal tract. Recently, E. corrodens is reported as a rare causative agent of empyematic lesion.
We report a case of 10-year-old girl with acute subdural abscess. She developed a high grade fever, swelling of the left periorbital area, right sided partial seizure and hemiplegia. Brain CT and MRI showed left parietal subdural abscess. Because intravenous antibiotic therapy was not effective enough and her neurological symptoms progressed, surgical drainage was performed in order to decompress the brain and to determine the causative agents. Through careful bacterial cultures, E. corrodensand Streptococcus constellatus were detected from the subdural abscess. After the drainage operation and a three week course of appropriate chemotherapy, the abscess completely disappeared and no sequela remained.

View full abstract

We report an 8-year-old boy with acute focal bacterial nephritis (AFBN). At the age of 3 months, he had a history of urinary tract infection and vesicoureteral reflux. He was admitted to our hospital because of high fever and costovertebral angle pain. Although acute pyelonephritis was suspected, neither pyuria nor cultures of blood and urine were positive. An initial ultrasonogram (US) of his kidneys was normal except for bilateral hydronephrosis. Two days later, however, a computed tomogra phy (CT) revealed a poorly enhanced mass in the upper pole of the right kidney. Similar findings were also observed by US. Under the diagnosis of AFBN, he received antibiotics for 3 weeks. Voiding cystourethrogram showed both-sided vesicoureteral reflux and he underwent an operation. At present the mass of the kidney still remains, albeit its size tends to decrease.
We suggest that an early examination of US or enhanced CT is necessary in cases with fever of unknown origin, considering the possibility of AFBN even if neither pyuria nor cultures of urine are positive.

View full abstract

A 33 year-old female was admitted with facial, trunk and limb eruptions, conjunctiva intrahaemorrhage, Koplik's spots in the pharynx and severe hypoxemia after fever and upper respiratory tract symptom. Infiltrative shadow of the whole right lung was seen on chest radiography. Fine crackles were seen in the lower left lung and in the whole right lung. Severe inflammation and liver dysfunction were indicated by blood test. Measles antibody IgM was high. The abnormal interstitial shadows were confirmed in greater detail by chest computed tomography. Her condition was diagnosed as measles pneumonia. A combination therapy with steroid pulse, high dose vitamin A, and γ globulin was started, after which the patient gradually improved, indicating the effectiveness of this combination therapy for severe adult measles pneumonia.

View full abstract