PubMed Health⌕ Search

Biomedical subjects

Cheng-Hsun Chiu

Publications and source records attributed to Cheng-Hsun Chiu.

81 records · Page 5Linked to original sources
PubMed2002

Nucleotide and amino acid sequences of oriT-traM-traJ-traY-traA-traL regions and mobilization of virulence plasmids of Salmonella enterica serovars enteritidis, gallinarum-pullorum, and typhimurium.

The virulence plasmid of Salmonella enterica serovar Gallinarum-Pullorum (pSPV) but not those of Salmonella enterica serovars Enteritidis (pSEV) and Typhimurium (pSTV) can be readily mobilized by an F or F-like conjugative plasmid. To investigate the reason for the difference, the oriT-traM-traJ-traY-traA-traL regions of the three salmonella virulence plasmids (pSVs) were cloned and their nucleotide and deduced amino acid sequences were examined. The cloned fragments were generally mobilized more readily than the corresponding full-length pSVs, but the recombinant plasmid containing the oriT of pSPV was, as expected, more readily mobilized, with up to 100-fold higher frequency than the recombinant plasmids containing the oriT of the other two pSVs. The nucleotide sequences of the oriT-traM-traJ-traY-traA-traL region of pSEV and pSTV were almost identical (only 4 bp differences), but differed from that of pSPV. Major nucleotide sequence variations were found in traJ, traY, and the Tra protein binding sites sby and sbm. sby of pSPV showed higher similarity than that of pSEV or pSTV to that of the F plasmid. The reverse was true for sbm: similarity was higher with pSEV and pSTV than with pSPV. In the deduced amino acid sequences of the five Tra proteins, major differences were found in TraY: pSEV's TraY was 75 amino acids, pSTV's was 106 amino acids, and pSPV's was 133 amino acids; and there were duplicate consensus betaalphaalpha fragments in the TraY of pSPV and F plasmid, whereas there was only a single betaalphaalpha fragment in that of pSEV and pSTV.

Amino Acid Sequence↗
PubMed2002

Mycobacterium marinum infection in Taiwan.

Mycobacterium marinum often causes skin infections, tenosynovitis, arthritis, and osteomyelitis, and occasionally results in severe disseminated infections in immunocompromised patients. In this study, the clinical features of 14 cases of M. marinum infection were retrospectively analyzed. One patient had septic arthritis, the other 13 had skin infections and/or tenosynovitis. It usually took 2 months or longer for a definite diagnosis to be made in these patients. Three of the 14 patients were cured using clarithromycin alone or in combination with rifampin plus ethambutol. Most patients did not respond to conventional antituberculosis agents. Pulsed-field gel electrophoresis and infrequent-restriction-site polymerase chain reaction are efficient tools for the molecular typing of M. marinum. Both methods yielded a concordant result, and 4 of 12 isolates were genetically closely related to each other based on their banding patterns. This study indicates that these isolates were derived from the same clone. Because M. marinum infection is curable, early diagnosis is important. Poor healing of wounds after exposure to aquatic animals appears to be the most important clinical clue indicating the need for culture and inclusion of M. marinum infection in the differential diagnosis.

Adolescent↗
PubMed2002

Successful treatment of meningitis caused by highly-penicillin-resistant Streptococcus mitis in a leukemic child.

In recent years, viridans streptococci have been reported with increasing frequency to cause infections in neutropenic cancer patients. Streptococcus mitis, one of the species included among viridans streptococci, is the most resistant to beta-lactam antibiotics in this group. Bacterial meningitis presenting without pleocytosis in the cerebrospinal fluid (CSF) is rare, and this situation could be confusing to physicians. It is also an uncommon infectious complication in leukemic patients with neutropenia. In patients with leukopenia caused by myelosuppression after chemotherapy, bacterial meningitis must be considered a possibility when a patient develops meningeal signs, even if no pleocytosis is found in the CSF. We report on a 6-year-old boy with leukemia and neutropenia who developed sepsis and meningitis caused by S. mitis with high-level resistance to penicillin and cephalosporins (MIC of both, >2 mg/l); he was a long-term survivor receiving chronic trimethoprim-sulfamethoxazole prophylaxis. The patient was successfully treated with a combination of vancomycin, ceftriaxone, and granulocyte-colony-stimulating factor.

Bacteremia↗
PubMed2002

Multidrug-resistant non-typhoid Salmonella infections in a medical center.

Due to the high incidence of antimicrobial-resistant Salmonella in Taiwan, the emergence of multidrug-resistant Salmonella has become of particular concern. This retrospective study assessed the clinical features of patients with multidrug-resistant Salmonella treated from January 1998 through June 2000. A total of 201 children and 33 adults with multidrug-resistant Salmonella infections treated during a 2.5-year period were included. Sixty-percent of these patients had used antibiotics before multidrug-resistant Salmonella infection developed. The incidence of extra-intestinal infections was higher in adults (51.4%) than in children (4.9%). Infection with an invasive serotype of Salmonella, such as Salmonella choleraesuis, and host factors appeared to be predisposing factors for bacteremia or extra-intestinal infections. None of the patients had mortality attributable to multidrug-resistant salmonellosis. The increasing rate of resistance to third-generation cephalosporins and fluoroquinolones and the high multidrug-resistant rate of S. choleraesuis found in this study indicate the importance of judicious use of antimicrobial agents in both humans and animals to reduce the selection and spread of resistant strains.

Adult↗
PubMed2002

Duration of antimicrobial therapy for non-typhoid Salmonella bacteremia in healthy children.

Medical records of patients less than 17 years of age with positive blood culture for non-typhoid Salmonella from June 1996 through December 1998 at the Chang Gung Children's Hospital were collected. Patients were categorized into 3 groups according to the duration of effective antibiotic therapy they received. Group 1 received effective antibiotic therapy for less than 7 days; Group 2 for 7 to 9 days; and Group 3 for 10 days or more. Information on clinical presentations, laboratory data, and outcome were collected and analyzed. A total of 59 children were eligible, with 21 in Group 1, 17 in Group 2, and 21 in Group 3. Demographic data were similar among the 3 groups. No significant difference was found in the clinical symptoms and laboratory data among these groups, including white blood cell count, immature to total ratio of white blood cell, and serum C-reactive protein level. Salmonella group B (n = 37) were the most common isolates, followed by group D (n = 9), group C2 (n = 8), cholerasuis (n = 4), and C1 (n = 2). Third-generation cephalosporins were the final antibiotic therapy in most (90%) patients, and no isolates showed resistance to these agents in this study. No focal suppurative complications were noted at the initial evaluation and in the 1-year period after treatment. No clinical recurrent diseases were noted during a follow-up period of at least 1 year. Results suggest that for otherwise healthy children with non-typhoid Salmonella bacteremia, less than 10 days of antibiotics therapy could be adequate if they are more than 1 year old and no focal extra-intestinal infection is noted in the initial evaluation.

Anti-Bacterial Agents↗
PubMed2002

Ceftriaxone-resistant Salmonella enterica serovar Hadar: evidence for interspecies transfer of blaCMY-2 in a Taiwanese university hospital.

The emergence of resistance to extended-spectrum cephalosporins in salmonellae is an increasing clinical problem. We report the characteristics of a ceftriaxone-resistant Salmonella enterica serovar Hadar strain collected in 2001 from a patient with a postoperative wound infection in a university hospital in Taiwan. Resistance to extended-spectrum cephalosporins was found to be due to production of the plasmid-mediated CMY-2 AmpC beta-lactamase. To our knowledge, this is the first report of S. hadar harboring blaCMY-2. Seven CMY-2-producing Escherichia coli isolates collected in 2000 were investigated for comparison. Conjugation experiments and plasmid analysis showed an identical plasmid carrying blaCMY-2 in both the Salmonella isolate and one E. coli isolate, suggesting the possibility that the Salmonella isolate acquired the resistance plasmid from E. coli. These findings suggest that measures are necessary to restrict antibiotic use and so prevent the spread and development of antibiotic resistance in Taiwan.

Aged↗
PubMed2001

Adherence of Burkholderia cepacia to respiratory tract epithelial cells and inhibition with dextrans.

Adherence of Burkholderia cepacia to cells of the respiratory tract of patients with cystic fibrosis (CF) appears to be a necessary precondition for colonization and infection. To date, no effective anti-adhesive strategy has been devised for preventing B. cepacia infection in CF patients. It was found in this study that B. cepacia adhered to respiratory epithelial cells both in vitro and in vivo. However, strains with cable-like pili (Cbl) exhibited the typical clump formation on pneumocytes, whereas non-cable piliated strains predominantly showed single-cell adherence. Dextrans (nominally 4000-10000 Da) significantly inhibited adhesion of B. cepacia to A549 pneumocytes. When compared on an equal weight basis, the nominally 10000 Da dextran was most inhibitory. A dose-dependent inhibitory effect (up to 80 mg ml(-1)) was observed for most strains. Dextran exerted less of an anti-adhesive effect on the two Cbl+ strains than on the others which were Cbl-. Dextrans appeared to block the adherence in a non-specific fashion, as shown by the observations that the inhibitory effect was readily reversible and oligosaccharides composed of 2-4 glucose units with the same alpha-1,6 linkage were not inhibitory. The mean molecular masses of dextrans used in this study, as determined by gel filtration and MS, were approximately 10-fold lower than those indicated by the manufacturers. Our data suggest that dextran of nominal molecular mass 4000 Da at a concentration of 40 mg ml(-1) (10 mM according to manufacturer's quoted molecular mass) or more may be useful in patients with CF to prevent colonization and infection with B. cepacia.

Animals↗
PubMedDate not supplied

Acute lymphoblastic leukemia and posterior fossa arachnoid cyst in a five-year-old girl.

The authors experienced a case of acute lymphoblastic leukemia whose leukemic karyotypes were associated with changes in chromosome 21 ploidy, and she was also found to have an arachnoid cyst in the posterior fossa. The association between arachnoid cyst and leukemia as described in the literature appear to be quite rare. The clinical and radiologic features of arachnoid cyst as well as cytogenetic abnormalities of the leukemic clones are described in the present article.

Arachnoid Cysts↗