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Cheng-Hsun Chiu

Publications and source records attributed to Cheng-Hsun Chiu.

At least 37 records · Page 2Linked to original sources

Bacterial enteric infections in children: etiology, clinical manifestations and antimicrobial therapy.

Bacterial enteric infections have a huge impact on human health, particularly among the pediatric population. Despite the explosion of knowledge of the pathogenesis of bacterial enteric infections experienced in the past decade, the number of diarrheal episodes and childhood deaths reported continues to increase in many areas of the world. Specific antimicrobial therapy is indicated for certain confirmed infections, notably shigellosis, enterotoxigenic and enteroinvasive Escherichia coli infections, typhoid fever and cholera. Antimicrobial therapy may have a role in severe and prolonged gastrointestinal illness caused by nontyphoid Salmonella and Campylobacter. However, the use of antimicrobial agents may increase the risk of hemolytic uremic syndrome in children with E. coli O157:H7 infection. Bacterial genome sequencing and better understanding of the pathogenic mechanisms involved in the onset of diarrhea are leading to new preventive interventions, such as enteric vaccines, which may have a significant impact on the magnitude of this human plague.

Anti-Bacterial Agents↗

Invasion of murine respiratory tract epithelial cells by Chryseobacterium meningosepticum and identification of genes present specifically in an invasive strain.

Chryseobacterium meningosepticum causes severe infections in infants or adults with underlying illness. The species is highly heterogeneous, genetically composed of subgroups with different pathogenicity. Eight strains of C. meningosepticum, representing four different genomic subgroups, were evaluated for their ability to penetrate Madin-Darby Canine Kidney (MDCK) epithelial cell monolayers and serum resistance. None of the strains showed cytotoxicity or penetration to the MDCK cells. All displayed resistance to the bactericidal activity of various normal human sera. A murine pulmonary infection model was used to compare the pathogenicity between a clinical isolate and an environmental isolate. C. meningosepticum were cleared from the lung of infected mice within 7 days following the intratracheal challenge. Electron microscopy demonstrated the large membrane protrusions, indicative of ruffles, and smaller, less organized membrane structures of the respiratory epithelial cells induced by the clinical isolate. Bacteria were observed to enter the cells as single entities in spacious vacuoles. Suppressive subtraction hybridization identified in the invasive isolate 35 distinct sequences associated with systems of energy production and conversion, transport, and secretion. In most cases, the identities between the references and the amino acid sequences deduced were low, suggesting that the functions of these sequences remain unknown.

Animals↗

Kawasaki disease in infants three months of age or younger.

BACKGROUND AND PURPOSE: Kawasaki disease (KD) is rare in infants < or =3 months of age. This study analyzed the features of KD in 25 infants < or =3 months of age treated from February 1994 to December 2004. METHODS: Basic characteristics, clinical, laboratory, echocardiographic, therapeutic, and follow-up data of the infants were obtained from chart records. RESULTS: There were 19 male and 6 female infants in this cohort. The frequency of the 5 principal clinical features was as follows: changes in lips and oral cavity, 84%; bilateral bulbar conjunctival injection without exudates, 80%; polymorphous exanthem, 68%; cervical lymphadenopathy, 28%; and changes in extremities, 24%. Six infants (24%) fulfilled criteria for KD including fever which persists for 5 or more days with at least 4 of the principal clinical criteria, and the remaining infants were classified as having incomplete KD (all of whom showed coronary involvement). Coronary artery dilatation was found in 20 infants (80%). One infant developed a medium-size aneurysm (5.2 mm), while the others had only coronary arterial ectasia or small aneurysms. Coronary artery aneurysms regressed within 1-year follow-up in all but one infant. No fatal or recurrent case was observed during the study period. CONCLUSIONS: Infants < or =3 months of age with KD usually presented with incomplete clinical features. A high proportion of coronary artery involvement was observed in this series. Echocardiography should be considered in very young infants with unexplained prolonged fever who do not present all of the principal clinical features of KD.

Coronary Vessels↗

Complete nucleotide sequence of pSCV50, the virulence plasmid of Salmonella enterica serovar Choleraesuis SC-B67.

We carried out comparative analysis on the sequences of two 50-kb virulence plasmids of Salmonella enterica serovar Choleraesuis strains SC-B67 (pSCV50) and RF-1 (pKDSC50). The two plasmids share over 99% sequence similarity. Ninety-two nucleotide variations at 42 sites were detected between the two plasmids; pSCV50 contains 24 nucleotide substitutions, 6 deletions, and 62 insertions, compared to pKDSC50. Two regions in pSCV50 appeared to be more susceptible to changes: one is the non-virulence-associated transfer region (27.5-33.0 K) and the other a function-unknown region (9.0-10.5 K). We re-annotated pSCV50 using more advanced tools and the up-to-date databases and corrected the inaccurate annotation in pKDSC50. The results indicate that virulence-related genes on the 50-kb plasmid are under negative selection, suggesting that they play important roles in the expression of virulence during the process of infection, while other genes in this plasmid tend to evolve neutrally.

Chromosome Mapping↗

Increasing ceftriaxone resistance in Salmonella isolates from a university hospital in Taiwan.

OBJECTIVES: Salmonella infection is a distressing health problem worldwide. This study reports the changing epidemiology of Salmonella infections in Taiwan during 1999-2003, with emphasis on increasing ceftriaxone resistance. METHODS: Records of Salmonella clinical isolates in Chang Gung Memorial Hospital during 1999-2003 were reviewed. All isolates were identified and antimicrobial susceptibility determined by standard methods. A total of 22 ceftriaxone-resistant isolates were investigated by PCR sequencing of the bla(TEM), bla(SHV), bla(CTX-M) and ampC genes. Southern-blot hybridization was used to localize the ampC gene. Infrequent-restriction-site PCR was used to genotype these isolates. RESULTS: A total of 3635 Salmonella isolates, including 3592 (98.8%) non-typhoid Salmonella, were identified. Serogroup B (55.6%) remained the most predominant, but the prevalence has been decreasing. In contrast, serogroup D infections have increased significantly from 13.6 to 22.8%. Overall resistance to ampicillin and chloramphenicol remained high, with the highest rate (91% to both drugs) observed in Salmonella enterica serotype Choleraesuis in 2003. A sudden upsurge of ciprofloxacin resistance from zero to 69% was found in S. Choleraesuis. Ceftriaxone resistance increased in several serogroups (0.8-2.1%; average, 1.5%). The resistance was associated with plasmid-mediated bla(CMY-2) in 14 cases and extended-spectrum beta-lactamases (ESBLs), including CTX-M-3 (n=6), SHV-2a (n=1) and SHV-12 (n=1), in others. Diverse serotypes and genotypes were found among the ceftriaxone-resistant isolates. CONCLUSIONS: Increasing ceftriaxone resistance in non-typhoid Salmonella appears to link to the spread of plasmid-mediated ampC or ESBL genes. Effective measures should be taken to prevent the problem worsening.

Adolescent↗

The genome sequence of Salmonella enterica serovar Choleraesuis, a highly invasive and resistant zoonotic pathogen.

Salmonella enterica serovar Choleraesuis (S. Choleraesuis), a highly invasive serovar among non-typhoidal Salmonella, usually causes sepsis or extra-intestinal focal infections in humans. S. Choleraesuis infections have now become particularly difficult to treat because of the emergence of resistance to multiple antimicrobial agents. The 4.7 Mb genome sequence of a multidrug-resistant S. Choleraesuis strain SC-B67 was determined. Genome wide comparison of three sequenced Salmonella genomes revealed that more deletion events occurred in S. Choleraesuis SC-B67 and S.Typhi CT18 relative to S. Typhimurium LT2. S. Choleraesuis has 151 pseudogenes, which, among the three Salmonella genomes, include the highest percentage of pseudogenes arising from the genes involved in bacterial chemotaxis signal-transduction pathways. Mutations in these genes may increase smooth swimming of the bacteria, potentially allowing more effective interactions with and invasion of host cells to occur. A key regulatory gene of TetR/AcrR family, acrR, was inactivated through the introduction of an internal stop codon resulting in overexpression of AcrAB that appears to be associated with ciprofloxacin resistance. While lateral gene transfer providing basic functions to allow niche expansion in the host and environment is maintained during the evolution of different serovars of Salmonella, genes providing little overall selective benefit may be lost rapidly. Our findings suggest that the formation of pseudogenes may provide a simple evolutionary pathway that complements gene acquisition to enhance virulence and antimicrobial resistance in S. Choleraesuis.

Bacterial Proteins↗

Resistance to fluoroquinolones linked to gyrA and par C mutations and overexpression of acr AB efflux pump in Salmonella enterica serotype Choleraesuis.

Between 2000 and 2002, 60 clinical isolates of Salmonella enterica serotype Choleraesuis were collected to investigate the mechanism of fluoroquinolone resistance. PCR and sequencing were performed to identify mutations in gyrA, gyrB, par C, the Acr AB-TolC efflux pump regulator, acr R, and the global regulons mar RAB and sox RS. All resistant strains showed mutations in the target genes leading to amino acid changes of Ser 83 Phe and Asp 87 Asn in GyrA and Ser 80 Ile in Par C. A mutation in gyrB was linked to the serotype genetic diversity but not to fluoroquinolone resistance. An efflux pump inhibitor, Phe-Arg-beta-naphthylamide, caused fourfold lower MIC of ciprofloxacin in the resistant isolates, indicating that efflux systems are involved in fluoroquinolone resistance. Western blot analysis showed moderate overproduction of Acr A in fluoroquinolone- resistant isolates. A mutation in acr R gave rise to an internal stop codon in both ciprofloxacin-resistant and -susceptible isolates, suggesting another serotype genetic diversity. No mutations were detected in mar RAB and sox RS among the isolates examined. Cross-resistance to three fluoroquinolones was observed, but gatifloxacin demonstrated relatively lower MICs than those of ciprofloxacin and levofloxacin. Fluoroquinolone resistance in S. Choleraesuis appears to be the combination effect of multiple mutations in various target genes and overexpression of the Acr AB-TolC efflux pump.

Blotting, Western↗

Clinical features and genotyping analysis of community-acquired methicillin-resistant Staphylococcus aureus infections in Taiwanese children.

BACKGROUND: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection in children without health care-associated risk factors has emerged. To evaluate the clinical features and genotyping analysis of CA-MRSA in children in Taiwan, we conducted this study. METHODS: Between July 2000 and June 2001, 198 episodes of S. aureus infection were identified in 191 children hospitalized at Chang-Gung Children's Hospital. The medical records of these children were retrospectively reviewed. The MRSA clinical isolates from each episode of infection, if available, were collected for pulsed-field gel electrophoresis (PFGE) typing and staphylococcal cassette chromosome mec (SCCmec) type determination. RESULTS: Among the 198 episodes of S. aureus infection, MRSA accounted for 47% of 114 CA infections and 62% of 84 hospital-acquired (HA) infections, respectively. Among 54 CA-MRSA infections, 32 episodes (59%) occurred in children without risk factors. Similar to HA-MRSA isolates, these CA-MRSA isolates were also multiresistant, with a high rate of resistance to clindamycin (93%) and erythromycin (94%), but 91% of them were susceptible to trimethoprim/sulfamethoxazole. Superficial soft tissue infection was the most common presentation, accounting for 65% of CA-MRSA infections. All 54 children with CA-MRSA infection recovered without sequelae, though 63% of 35 children with superficial soft tissue infection were treated with in vitro nonsusceptible antibiotics. Of the 83 clinical isolates (40 CA, 22 with no identified risk) available for analysis, 6 genotypes with 30 subtypes were identified. Three major PFGE patterns were identified, accounting for 94% of the isolates (92.5% for CA isolates, 95% for HA isolates). Type IV SCCmec was carried by 25 and 40% of CA and HA isolates, respectively. CONCLUSION: In Taiwan, MRSA was prevalent among pathogens of CA infections in children, and these CA isolates were multiresistant and genetically associated with HA isolates. In an area with a high prevalence of methicillin resistance, for children with putative S. aureus infection, even community-acquired, a glycopeptide-containing regimen should be considered for initial empirical therapy in the case of serious infection.

Adolescent↗

Clinical and laboratory manifestations of Kikuchi's disease in children and differences between patients with and without prolonged fever.

BACKGROUND: Kikuchi's disease (KD) is characterized by cervical lymphadenopathy with or without fever. It has been recognized worldwide but seldom reported in pediatric patients. METHODS: From January 1985 through December 2001, 64 patients younger than 18 years of age with pathologic proof of KD were enrolled in this study. The clinical manifestations, laboratory data and outcomes were reviewed. RESULTS: There were 35 male patients and 29 female patients with age ranging from 2 to 18 years and a median age of 16. All patients had cervical lymphadenopathy except 1 who had generalized lymphadenopathy. Lymph nodes of 32 patients (50%) were painful or tender or both. Lymphadenopathy was unilateral in 52 patients (82.5%). Lymphadenopathy associated with fever was observed in 21 patients (32.8%). Other signs such as skin rash, hepatomegaly or body weight loss were less common. Twenty-six patients (40.6%) had leukopenia and 2 patients had leukocytosis. Nearly one-fourth of the patients had mild liver dysfunction. Virologic or immunologic studies were normal in most patients. Patients with prolonged fever were more likely to have leukopenia (P < 0.05). All patients recovered, but 1 developed systemic lupus erythematosus 5 years later, and the other had vasculitis syndrome 2 years later. CONCLUSIONS: The clinical presentation of KD in pediatric patients is similar to that of adults. KD is a benign, self-limiting disease; prolonged fever occurred only in 32.8% of pediatric patients in our cohort. Leukopenia was the only feature significantly associated with prolonged fever.

Adolescent↗

Streptococcal toxic shock syndrome in children without skin and soft tissue infection: report of four cases.

UNLABELLED: Streptococcal toxic shock syndrome is a fulminant, highly fatal disease characterized by evidence of group A beta-haemolytic streptococcus infection and early shock with consecutive organ failure. In adults, affected individuals usually have preceding skin or soft tissue infection. However, in paediatric patients, except for varicella, the background focus is usually respiratory tract infection, and early diagnosis of streptococcal toxic shock syndrome in such patients is difficult. We report four previously healthy children with streptococcal toxic shock syndrome. Pharyngitis was identified in three cases. All of them had constitutional symptoms such as fever, vomiting, diarrhoea, abdominal pain and physical findings of tachycardia and diffuse abdominal tenderness, but no concomitant skin infection. CONCLUSION: Streptococcal toxic shock syndrome should be considered in paediatric patients with fever, vomiting, diarrhoea, abdominal pain and early shock. Early diagnosis, prompt initiation of antibiotics and aggressive fluid therapy are lifesaving for such patients.

Adolescent↗

Outbreak of dysentery associated with ceftriaxone-resistant Shigella sonnei: First report of plasmid-mediated CMY-2-type AmpC beta-lactamase resistance in S. sonnei.

We document the first report of plasmid-encoded CMY-2-type AmpC beta-lactamase identified among Shigella sonnei isolates resistant to ceftriaxone and obtained after an outbreak of bacillary dysentery in Taiwan. One hundred eighty-two children in two elementary schools in Yu-Li, Taiwan, where an outbreak occurred after a typhoon hit this area in 2001, were enrolled in this study. Clinical and epidemiologic data on the infected children were collected. Pulsed-field gel electrophoresis (PFGE) was performed on the isolates to determine the genetic relatedness of outbreak strains. Plasmid analysis and PCR were performed to identify beta-lactamase genes responsible for ceftriaxone resistance. Forty-seven children from the two elementary schools were culture positive for S. sonnei in this outbreak. Twenty-three children were asymptomatic. Of the total isolates 55.3% were resistant to ampicillin. One hundred percent of the isolates obtained from children in school A were initially susceptible to both ampicillin and ceftriaxone. Of isolates obtained from school B 96.2% were nonsusceptible to ceftriaxone. However, two isolates from school A developed resistance to ampicillin during the course of treatment. All 18 available isolates showed closely related PFGE patterns (4, 4a, 4b, and 4c). CMY-2-type AmpC beta-lactamase was responsible for ceftriaxone resistance in ceftriaxone-nonsusceptible isolates; Southern blot hybridization confirmed that such a resistance gene was located on the plasmid. This is the first report of plasmid-mediated CMY-2-type AmpC beta-lactamase in S. sonnei. Ampicillin-resistant isolates can develop during the course of antibiotic treatment.

Adolescent↗

Epidemiologic relationship between fluoroquinolone-resistant Salmonella enterica Serovar Choleraesuis strains isolated from humans and pigs in Taiwan (1997 to 2002).

The emergence of ciprofloxacin-resistant Salmonella enterica serovar Choleraesuis in recent years has become an important public health issue in Taiwan. The resistant strains that cause human infections are considered to be from pigs. In this study, we characterized 157 swine and 42 human Salmonella serovar Choleraesuis isolates by pulsed-field gel electrophoresis (PFGE) and drug susceptibility testing to investigate the epidemiologic relationship among the isolates. By PFGE analyses, two major clusters (clusters GA and GB) were identified. Isolates in cluster GA were of both human and swine origins, while those in cluster GB were from pigs only. Among the various genotypes identified, genotype gt-1a was the most prevalent, which was found in 71% (30 of 42) and 48% (76 of 157) of human and swine isolates, respectively. The susceptibility tests for the 106 gt-1a isolates identified 44 susceptibility profiles and showed that 73% of human isolates and 34% of swine isolates were resistant to three fluoroquinolones (ciprofloxacin, enrofloxacin, and norfloxacin). Our findings indicate that a clonal group of Salmonella serovar Choleraesuis may have been circulating in human and swine populations in Taiwan for years and that the fluoroquinolone-resistant Salmonella serovar Choleraesuis strains most likely evolved from a gt-1a clone that emerged in 2000 and that then caused widespread infections in humans and pigs. Nevertheless, it is still debatable whether those Salmonella infections in humans are caused by isolates derived from pigs, on the basis of the higher fluoroquinolone and other antimicrobial resistance percentages in human isolates than in pig isolates.

Animals↗

Development of a multiplex PCR and SHV melting-curve mutation detection system for detection of some SHV and CTX-M beta-lactamases of Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae in Taiwan.

Infection by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae has been increasing in Taiwan. Accurate identification of the ESBL genes is necessary for surveillance and for epidemiological studies of the mode of transmission in the hospital setting. We describe herein the development of a novel system, which consists of a multiplex PCR to identify bla(SHV), bla(CTX-M-3)-like, and bla(CTX-M-14)-like genes and a modified SHV melting-curve mutation detection method to rapidly distinguish six prevalent bla(SHV) genes (bla(SHV-1), bla(SHV-2), bla(SHV-2a), bla(SHV-5), bla(SHV-11), and bla(SHV-12)) in Taiwan. Sixty-five clinical isolates, which had been characterized by nucleotide sequencing of the bla(SHV) and bla(CTX-M) genes, were identified by the system. The system was then used to genotype the ESBLs from 199 clinical isolates, including 40 Enterobacter cloacae, 68 Escherichia coli, and 91 Klebsiella pneumoniae, collected between August 2002 and March 2003. SHV-12 (80 isolates) was the most prevalent type of ESBL identified, followed in order of frequency by CTX-M-3 (65 isolates) and CTX-M-14 (36 isolates). Seventeen (9%) of the 199 clinical isolates harbored both SHV- and CTX-M-type ESBLs. In contrast to Enterobacter cloacae, the majority of which produced SHV-type ESBLs, E. coli and K. pneumoniae were more likely to possess CTX-M-type ESBLs. Three rare CTX-M types were identified through sequencing of the bla(CTX-M-3)-like (CTX-M-15) and bla(CTX-M-14)-like (CTX-M-9 and CTX-M-13) genes. The system appears to provide an efficient differentiation of ESBLs among E. coli, K. pneumoniae, and Enterobacter cloacae in Taiwan. Moreover, the design of the system can be easily adapted for similar purposes in areas where different ESBLs are prevalent.

Enterobacter cloacae↗

Community-acquired disseminated methicillin-resistant Staphylococcus aureus infection: case report and clinical implications.

A 6-year-old girl with community-acquired disseminated infection caused by methicillin-resistant Staphylococcus aureus (MRSA) is described. She had sepsis, meningo-encephalitis, pyomyositis, osteomyelitis, pericarditis and pulmonary embolisation caused by a multi-resistant strain of MRSA. Vancomycin is not routinely recommended as the first-line antimicrobial agent for suspected Staphylococcus aureus infection; however, it should be considered pending susceptibility results in patients presenting with severe sepsis in areas where the prevalence of MRSA is high.

Bone Diseases, Infectious↗

Epstein-Barr virus-associated infectious mononucleosis and risk factor analysis for complications in hospitalized children.

The characteristics of Epstein-Barr virus (EBV)-associated infectious mononucleosis (IM) in Chinese children are rarely reported. To evaluate the clinical presentations and risk factors for complications of EBV-associated IM in previously healthy children in Taiwan, hospitalized children with the diagnosis of IM due to EBV infection from January 1998 to December 2002 were enrolled. Patients had to fulfill the serologic criteria for the diagnosis of primary EBV infection [viral capsid antigen immunoglobulin M (IgM)-(+), viral capsid antigen IgG-(+), and anti-Epstein-Barr nuclear antigen (EBNA) antibody-(-) with exclusion of other concurrent infections or underlying diseases]. Ninety eight children were eligible, with 79% younger than 5 years old (mean, 4.0 +/- 2.3 years). The male-to-female ratio was 2:1. Nearly all patients suffered from fever (mean duration 10.3 +/- 6.0 days). Cough/rhinorrhea, tonsillopharyngitis, cervical lymphadenopathy and hepatosplenomegaly were found over half of the patients. Atypical lymphocytosis (mean, 12 +/- 13%) and elevated serum aspartate aminotransferase (AST; mean, 167 +/- 183 IU/L) and alanine aminotransferase (mean, 221 +/- 222 IU/L) were the most striking laboratory findings. Various complications, including hematologic, hepatobiliary, central nervous system, and obstructive airway problems occurred in about 20% of patients with significantly prolonged course of hospitalization. All patients recovered uneventfully under supportive and immunomodulating management. Female gender, no signs of tonsillopharyngitis, white blood cell count < or =10,000/mm3 and AST > or =150 IU/L were significant risk factors for the occurrence of complications. Clinicians should monitor such patients closely and give proper treatment to decrease possible morbidity or even mortality should complications occur.

Adolescent↗

Antimicrobial resistance in nontyphoid Salmonella serotypes: a global challenge.

Increasing antimicrobial resistance in nontyphoid Salmonella species has been a serious problem for public health worldwide. The high rate of resistance is hampering the use of conventional antibiotics, and growing resistance to newer antimicrobial agents is aggravating the situation. The circumstances of occurrence and spread of antimicrobial resistance are complex; however, a major cause is the widespread use of antimicrobial agents in food animals, particularly in animal feed. Genetic analysis has indicated that the source of resistance is frequently a transferable plasmid. Recent studies have revealed that some serotype-specific virulence plasmids form hybrid plasmids through recombination with resistance plasmids or acquire gene cassettes consisting of multiple resistance genes. Such evolutionary events provide a virulent strain the advantage of survival in an unfavorable drug environment. In view of the serious implications associated with drug-resistant Salmonella species, a more deliberate use of antibiotics in both human medicine and animal industry is warranted. Continued surveillance of antimicrobial resistance and use of antimicrobial agents in food animals is also indispensable.

Animals↗

Skin manifestations of Kikuchi-Fujimoto disease: case report and review.

UNLABELLED: Kikuchi-Fujimoto disease (KFD) is a histiocytic necrotising lymphadenitis, which is a benign disease of unknown aetiology. Misdiagnosing KFD as lymphoma or systemic lupus erythematosus is not uncommon due to the similarity of clinical and histopathological features of these diseases. A 12-year-old female suffered from cervical lymphadenopathy, leukocytopenia, fever and especially skin rash. The biopsy of the lymph node was compatible with KFD. The skin biopsy showed interface alterations with vacuolar degeneration of the basal cells suggesting lupus erythematosus; however, the patient did not fulfill the diagnostic criteria for systemic lupus erythematosus. After treatment with acetaminophen, fever subsided and the skin rashes disappeared without relapse during a 10-month follow-up period. CONCLUSION: The histopathological findings of cutaneous lesions in KFD are usually similar to those observed in the involved lymph nodes. This report suggests that interface change might be one of the pathological features of the cutaneous manifestations of KFD.

Biopsy↗