Biomedical subjects

W C Ko

Publications and source records attributed to W C Ko.

At least 19 recordsLinked to original sources

PubMed2006

Endocarditis and pericarditis complicating pneumococcal bacteraemia, with special reference to the adhesive abilities of pneumococci: results from a prospective study.

The incidence of pneumococcal cardiac infections is unknown and the pathogenicity of such complications is poorly understood. In a prospective, international, observational study, eight of 844 patients hospitalised with Streptococcus pneumoniae bacteraemia developed endocarditis (n = 5) or pericarditis (n = 3). The clinical and microbiological characteristics of these patients were compared with those of control patients. The corresponding incidence of pneumococcal endocarditis was c. 1-3/1 million inhabitants/year. There was no common pattern in the medical history of patients with an infectious cardiac complication. The severity of illness upon admission was comparable with that for patients without infectious cardiac complications, as was the 14-day mortality rate (25% and 17%, respectively). For encapsulated S. pneumoniae, no significant differences were found between patients with infectious cardiac complications and controls in adherence assays. However, non-encapsulated S. pneumoniae showed higher hydrophobicity and increased adherence to human epithelial cells.

Adolescent↗

PubMed2006

Feasibility of transradial coronary angiography and angioplasty in Chinese patients.

OBJECTIVE: To assess the clinical applicability, efficacy, and safety of coronary angiography and angioplasty via a transradial approach in local Chinese patients. DESIGN: Prospective case series. SETTING: Regional hospital, Hong Kong. PATIENTS: All patients undergoing coronary angiography and coronary angioplasty between 1 January and 30 June 2004. INTERVENTIONS: Transradial coronary angiography and coronary angioplasty. MAIN OUTCOME MEASURES: Feasibility, success rate, and complications. RESULTS: A total of 268 coronary angiographies (62% of all coronary angiographies) and 118 coronary angioplasties (48% of all coronary angioplasties) were performed via a transradial approach. The procedural success rate for coronary angiography was 93.7% with a mean duration of 21.8 (standard deviation, 13.5) minutes compared with 17.9 (10.0) minutes for angiography via a femoral approach. Most (99%) patients were free from any complications. Of those patients who underwent elective transradial coronary angiography in the morning, 64% were discharged on the same day. Comparison of data in the first half of the study period with those in the second half revealed a significant increase in the percentage of coronary angiographies performed via a transradial approach (from 52% to 73%, P<0.0001), and an improved procedural success rate (from 91.5% to 95.3%, P=0.1). For transradial coronary angioplasty, the procedural success rate was 98%. A total of 246 lesions (2.08 lesions per patient) were treated with no procedure-related complications. CONCLUSIONS: Transradial coronary angiography and angioplasty are feasible in a significant proportion of local Chinese patients and achieve a high success rate and low complication rate. It tends to prolong procedural duration, but improves patients' comfort and permits earlier ambulation and discharge. The procedural success rate improves with accumulating experience.

Aged↗

PubMed2005

Klebsiella pneumoniae fascial space infections of the head and neck in Taiwan: emphasis on diabetic patients and repetitive infections.

OBJECTIVES: To assess the epidemiological features, clinical characteristics, treatment, and outcome of head and neck infections caused by Klebsiella pneumoniae. METHODS: We reviewed records of four common aerobic pathogens isolated by the microbiological laboratory of a teaching hospital in Taiwan from July 1995 to December 1999. Patients aged 14 or older with community-acquired fascial space infections of head and neck were identified by review of medical records and included in the study. RESULTS: A total of 100 cases were identified, and K. pneumoniae was the most common pathogen of monomicrobial infections (48%), followed by viridans streptococci (15%). Polymicrobial infections were noted in 35 cases. In comparison with patients with infections not caused by K. pneumoniae, those with monomicrobial K. pneumoniae infections were older (P = 0.04) and had a higher prevalence of diabetes mellitus (P < 0.001), a longer duration of antimicrobial therapy (P = 0.007), a longer hospital stay (P = 0.001), and more repetitive infections (P = 0.001). All but one of K. pneumoniae isolates were susceptible to first generation cephalosporins and aminoglycosides. CONCLUSIONS: K. pneumoniae is an important endemic pathogen of fascial space infections of head and neck in Taiwan, especially among diabetics. Physicians should be aware of the tendency of this organism to cause repetitive infection.

Adult↗

PubMed2003

FT-IR microspectroscopic study of shot formation in melt-blown webs.

We used Fourier transform infrared (FT-IR) microspectroscopy to investigate the chemical nature of fibers and defects called "shot" in melt-blown webs. Spectral differences were observed and evaluated in light of known thermal and oxidative degradation reactions for conditions comparable to those we used for melt blowing. Three different isotactic polypropylene polymers were evaluated in terms of the amount of shot produced and the amount of oxidative degradation exhibited by fibers and shot particles from each polymer. Little oxidative degradation was observed in fibers and the amount of degradation in fibers varied little for the three polymers we evaluated. Substantially more degradation was observed in shot particles, and the amount of degradation varied among the three polymers. Compared to polymer bound for fibers, we concluded that high temperature and mechanical shear in the extruder may introduce more chain scission in polymer bound for shot particles. Autoxidation reactions may occur after melt exits the die, and our data indicated that more oxidative degradation occurred in polymer that became shot particles than polymer that became fibers. The most favorable site for oxidation seemed to be tertiary rather than methylene hydrogen. Overall, the thermal history of polymer that becomes shot particles may be significantly different than the thermal history of polymer that becomes fibers, and this difference may have influenced shot formation.

Hot Temperature↗

PubMed2001

Serotyping and antimicrobial susceptibility of group B Streptococcus over an eight-year period in southern Taiwan.

The increase in penicillin resistance among pneumococci and viridans streptococci and the development of serotype-specific conjugate vaccine have increased the need for knowledge of the antimicrobial susceptibility and the capsular serotypes of group B streptococci. Over an 8-year period, 351 group B streptococcal isolates from southern Taiwan were tested for antimicrobial susceptibility and serotype determination. Eighty-seven percent of the isolates were typeable. Types III (28.5%) and V (27.1%) were the most common serotypes. The occurrence of type V isolates increased with age, while that of type III isolates decreased with age, showing a predominance in children less than 1 year of age. Of 118 isolates from cases of invasive infection, types Ia, Ib, II, III, IV, and V accounted for 12.7, 11.9, 0.8, 33, 1.7, and 26.3%, respectively. Using the agar dilution method, all isolates were found to be susceptible to penicillin, cefotaxime, and vancomycin, 99.4% to ofloxacin, 78.1% to chloramphenicol, 63.2% to azithromycin, 62.6% to erythromycin, 57.3% to clindamycin, and 2.8% to tetracycline. Chloramphenicol resistance was associated with type III isolates (59 of 100, 59%) and erythromycin and azithromycin resistance with type Ib isolates (25 of 33 176%], and 21 of 33 [64%], respectively). Thus, 72% of the isolates from invasive infections were serotype III, V, or Ia, and penicillin remains the drug of choice for treatment or prophylaxis of group B streptococcal infections in southern Taiwan, despite the high prevalence of penicillin resistance among Streptococcus pneumoniae and viridans streptococci.

Adolescent↗

PubMed2001

New method for predicting efficiency of heating by measuring bioimpedance during radiofrequency catheter ablation in humans.

INTRODUCTION: Efficiency of heating (defined as the average temperature divided by the average power) during radiofrequency (RF) catheter ablation (RFCA) can be predicted by the electrode-tissue contact pressure before RFCA. To predict the efficiency of heating during RFCA, we prospectively measured bioimpedance and correlated the bioimpedance with the efficiency of heating in patients undergoing RFCA for supraventricular tachycardias. METHOD AND RESULTS: Of 239 RF applications in 55 patients, bioimpedance was measured from the distal pair of the electrodes of the ablation catheter using an extremely low current (10 microA at 45 kHz). Tip electrode temperature was measured with a closed-loop RF generator. Efficiency of heating and the difference (delta bioimpedance) between preablation bioimpedance (measured from the target ablation site) and baseline bioimpedance (measured in the right atrium without tissue contact) were calculated. There was significant positive correlation between preablation bioimpedance and efficiency of heating (regression coefficient = 0.053; P = 0.003) and between delta bioimpedance and efficiency of heating (regression coefficient = 0.067; P = 0.003). The highest degree of correlation was found during RFCA of the accessory pathways in the left free wall (regression coefficient = 0.14; P < 0.01). With preablation delta bioimpedance >21.5 ohms, applications targeted at the left free-wall, left posteroseptal, or right septal accessory pathways had a greater likelihood of achieving effective tissue heating (defined as maximal temperature achieved >55 degrees C). CONCLUSION: Both preablation bioimpedance and delta bioimpedance have positive correlation with efficiency of heating during RFCA of supraventricular tachycardia. Measuring preablation bioimpedance appears to be a useful tool for predicting the efficiency of heating during RFCA.

Adolescent↗

PubMed2001

Mechanisms of relaxant action of S-petasin and S-isopetasin, sesquiterpenes of Petasites formosanus, in isolated guinea pig trachea.

We investigated the mechanisms of action of S-petasin and S-isopetasin, from Petasites formosanus Kitamura which is used as a folk medicine for treating hypertension, tumors, and asthma in Taiwan. The tension changes of tracheal segments were isometrically recorded on a polygraph. S-Petasin and S-isopetasin non-competitively inhibited cumulative histamine-, and carbachol-induced contractions with an exception that S-isopetasin produced a parallel, rightward shift of the concentration-response curve of carbachol in a competitive manner. S-Petasin also non-competitively inhibited cumulative Ca(2+)-induced contractions in depolarized (K+, 60 mM; histamine, 100 microM; or carbachol, 10 microM) guinea-pig tracheas. S-Isopetasin did in depolarized (K+, 60 mM) trachea too. The nifedipine (10 microM)-remaining tension of carbachol (0.2 microM)-induced precontraction was further relaxed by S-petasin or S-isopetasin, suggesting that no matter whether either blocked VDCCs or not, S-petasin or S-isopetasin may have other mechanisms of relaxant action. The relaxant effect of S-petasin or S-isopetasin was unaffected by the presence of propranolol (1 microM), 2',5'-dideoxyadenosine (10 microM), methylene blue (25 microM), glibenclamide (10 microM), N omega-nitro-L-arginine (20 microM), or alpha-chymotrypsin (1 U/ml). However, S-petasin (100-300 microM), but not S-isopetasin, significantly inhibited cAMP-, but not cGMP-dependent PDE activity of the trachealis. The above results reveal that the mechanisms of relaxant action of S-petasin and S-isopetasin may be primarily due to its non-specific antispasmodic and antimuscarinic effects, respectively.

Animals↗

PubMed2001

Multicenter surveillance of antimicrobial resistance of major bacterial pathogens in intensive care units in 2000 in Taiwan.

A susceptibility surveillance study of 1,274 bacterial isolates recovered from various clinical specimens from patients in intensive care units (ICUs) of five major teaching hospitals was carried out from March, 2000, to June, 2000, in Taiwan. This study demonstrated a high rate (66%) of oxacillin resistance in Staphylococcus aureus (ORSA), a high rate of nonsusceptibility to penicillin (intermediate, 50% and highly resistant, 8%), and high rates of cefotaxime nonsusceptibility for S. pneumoniae (intermediate, 29% and resistant, 4%), Enterobacter cloacae (57%), Serratia marcescens (34%), and Citrobacter freundii (60%). High rate of ceftazidime nonsusceptibility for Pseudomonas aeruginosa (22%), and high rates of imipenem nonsusceptibility for P. aeruginosa (15%) and Acinetobacter baumannii (22%) were also found. The percentage (11.9%) of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli was greater than that (11.3%) for Klebsiella pneumoniae. Rates of quinupristin-dalfopristin nonsusceptibility for S. pneumoniae (42%), Enterococcus faecium (71%), and ORSA (39%) were high, but no vancomycin-resistant enterococci were found in this study. The resistance rates of some pathogen varied by institution or type of ICUs. Surveillance for antimicrobial resistance among bacterial pathogens in hospitals, particularly in ICU settings with a preexisting higher resistance burden, is mandatory in establishing and/or modifying guidelines for empirical treatment of severe infections in ICU patients caused by these antimicrobial-resistant pathogens.

Bacteria↗

PubMed2001

Candidaemia in patients with dialysis-dependent acute renal failure: aetiology, predisposing and prognostic factors.

BACKGROUND: Infections remain the major cause of death among patients with acute renal failure (ARF), especially in severe ARF necessitating dialysis therapy (ARF(d)). Although the clinical features and outcomes of candidaemia in various patient populations have been described, data concerning candidaemic episodes among patients with ARF(d) are scarce. This study investigated the aetiology, predisposing, and prognostic factors for candidaemia in the ARF(d) patient population. Three patient groups were investigated in this study. METHODS: During an 8-year study period from January 1992 to December 1999, 37 candidaemic episodes that developed among 653 ARF(d) patients were assigned to ARF(d) candidaemic group, and 170 candidaemic episodes developing in patients without ARF(d) or chronic uraemia as the non-ARF(d) candidaemic group, and 28 matched ARF(d) patients without candidaemia were assigned to the ARF(d) control group. Among these groups, clinical characteristics in ARF(d) candidaemia patients, predisposing factors, and outcomes were compared. Four management strategies including central catheter removal, anti-fungal therapy, both, or neither were applied. The prognostic factors for attributable death were evaluated by univariate analysis followed by the multivariate logistic regression analysis. RESULTS: The proportion of ARF(d) patients with candidaemia was significantly higher than in patients who had no ARF(d) or chronic uraemia (5.7% vs 0.15%, P<0.001). Compared with the non-ARF(d) candidaemic group, systemic lupus erythematosus (SLE), administration of corticosteroid, and central venous catheter-associated candidaemia were more common in the ARF(d) candidaemic group (P<0.05). In matched case-control study, multiple antibiotic usage was shown to be a predisposing factor for developing candidaemia in patients with ARF(d), and corticosteroid therapy has a marginal significance (P=0.059). The occurrence of candidaemia increased the mortality rate of ARF(d) (71% vs 39.2% in ARF(d) control group, P<0.05). By multivariate logistic analysis, the variables associated with attributable death in ARF(d) candidaemic group were identified to be an APACHE II score of >or=18, and anti-fungal therapy for >48 h. Central venous catheters were removed in 32 (86.5%) of the 37 ARF(d) candidaemic patients, among whom the 18 patients who had received anti-fungal therapy for >48 h had a lower attributable death rate than those patients who had not (27.8% vs 64.3%, P<0.05). Of the remaining five patients who did not have their catheter removed, three patients subsequently died and two patients improved only after catheter removal. CONCLUSIONS: The higher prevalence of candidaemia in ARF(d) patients is due to their underlying illnesses and multiplicity of predisposing factors, rather than ARF and dialysis therapy per se. Predisposing factors include SLE, indwelling central venous catheter, multiple antibiotic usage, and corticosteroid therapy. Prompt anti-fungal therapy and catheter removal should be mandatory for ARF(d) patients with candidaemia.

Acute Kidney Injury↗

PubMed2001

In vitro and in vivo combinations of cefotaxime and minocycline against Aeromonas hydrophila.

The activities of cefotaxime and minocycline against Aeromonas hydrophila were investigated. Cefotaxime (4 times the MIC) plus minocycline (0.75 times the MIC) elicited an inhibitory effect for 48 h in a time-kill study, and more infected mice treated with both drugs survived (91%) than survived after treatment with cefotaxime (9%) or minocycline (44%) alone, suggesting that cefotaxime and minocycline act synergistically against A. hydrophila.

Aeromonas hydrophila↗

PubMed2001

Metallo-beta-lactamases in clinical Pseudomonas isolates in Taiwan and identification of VIM-3, a novel variant of the VIM-2 enzyme.

A total of 209 clinical isolates of Pseudomonas (193 Pseudomonas aeruginosa, 10 P. putida, 4 P. stutzeri, and 2 P. fluorescens isolates) with reduced susceptibilities to imipenem and/or ceftazidime were subjected to PCR assays with primers specific for bla(IMP-1), bla(IMP-2), bla(VIM-1), and bla(VIM-2) and sequence analysis to identify the metallo-beta-lactamases (MBLs) prevalent among these organisms in Taiwan; and 21 isolates gave positive results. Five isolates including two P. putida and three P. stutzeri isolates were found to carry bla(IMP-1), and six isolates including five P. putida and one P. stutzeri isolates harbored bla(VIM-2). The remaining 10 isolates were P. aeruginosa, and all were found to carry a novel variant of bla(VIM-2), designated bla(VIM-3). There are only two nucleotide differences between bla(VIM-2) and bla(VIM-3), leading to two amino acid alterations. Our findings indicate that VIM-2 and its variant have become the most prevalent metalloenzymes in Pseudomonas in Taiwan. Southern hybridization with the bla(VIM-2)-, bla(VIM-3)-, and bla(IMP-1 )-specific probes revealed that only two VIM-2-producing P. putida isolates appeared to carry the MBL gene on plasmids. Pulsed-field gel electrophoresis showed that six VIM-3-producing P. aeruginosa isolates and two IMP-1-producing P. stutzeri isolates were genetically related, suggesting that the spread of these MBL genes in Taiwan could be due to clonal dissemination as well as genetic exchange between different clones.

DNA Primers↗

PubMed2001

Identification of a plasmid encoding SHV-12, TEM-1, and a variant of IMP-2 metallo-beta-lactamase, IMP-8, from a clinical isolate of Klebsiella pneumoniae.

A multidrug-resistant plasmid encoding TEM-1, SHV-12, and a variant of IMP-2 metallo-beta-lactamase, designated IMP-8, was identified from a clinical isolate of Klebsiella pneumoniae. There are four nucleotide differences between bla(IMP-2) and bla(IMP-8), resulting in two amino acid differences. bla(IMP-8) was also found to be carried by an integron-borne gene cassette similar to the bla(IMP-2) cassette.

Amino Acid Sequence↗

PubMed2001

Outbreak of infection with multidrug-resistant Klebsiella pneumoniae carrying bla(IMP-8) in a university medical center in Taiwan.

Klebsiella pneumoniae strains with the transferable carbapenem-hydrolyzing metallo-beta-lactamases, which include IMP- and VIM-type enzymes, remain extremely rare. To investigate whether IMP- or VIM-producing K. pneumoniae isolates had spread at a university medical center in Taiwan, a total of 3,458 clinical isolates of K. pneumoniae consecutively collected in 1999 and 2000 were tested by the agar diffusion method, colony hybridization, PCR, and nucleotide sequencing. A total of 40 isolates (1.2%), or 17 nonrepetitive isolates, from 16 patients were found to carry bla(IMP-8), a metallo-beta-lactamase gene recently identified from a K. pneumoniae strain in Taiwan. Carriage of bla(VIM) or other bla(IMP) genes was detected in none of the remaining isolates. Of the 17 nonrepetitive bla(IMP-8)-positive isolates, 15 isolates (88.2%) appeared susceptible to imipenem (MICs, <or=4 microg/ml) and meropenem (MICs, <or=1 microg/ml), indicating the difficulty in detecting bla(IMP-8) in K. pneumoniae by routine susceptibility tests; 14 isolates (82.4%) produced SHV-12 as well; and 14 isolates (82.4%) were also resistant to fluoroquinolones. The organisms caused wound infections in eight patients and bloodstream infections in three patients. They were not directly associated with the death of nine patients. Before the recovery of the bla(IMP-8)-positive isolates, all 16 patients had undergone various surgical procedures, and 15 patients had been admitted to the surgical intensive care unit, suggesting a nosocomial outbreak. Two major patterns were observed by pulsed-field gel electrophoresis for 14 of the 17 nonrepetitive isolates, indicating that the clonal spread was mainly responsible for the outbreak.

Adult↗

PubMed2001

Outcome of cephalosporin treatment for serious infections due to apparently susceptible organisms producing extended-spectrum beta-lactamases: implications for the clinical microbiology laboratory.

Although extended-spectrum beta-lactamases (ESBLs) hydrolyze cephalosporin antibiotics, some ESBL-producing organisms are not resistant to all cephalosporins when tested in vitro. Some authors have suggested that screening klebsiellae or Escherichia coli for ESBL production is not clinically necessary, and when most recently surveyed the majority of American clinical microbiology laboratories did not make efforts to detect ESBLs. We performed a prospective, multinational study of Klebsiella pneumoniae bacteremia and identified 10 patients who were treated for ESBL-producing K. pneumoniae bacteremia with cephalosporins and whose infecting organisms were not resistant in vitro to the utilized cephalosporin. In addition, we reviewed 26 similar cases of severe infections which had previously been reported. Of these 36 patients, 4 had to be excluded from analysis. Of the remaining 32 patients, 100% (4 of 4) patients experienced clinical failure when MICs of the cephalosporin used for treatment were in the intermediate range and 54% (15 of 28) experienced failure when MICs of the cephalosporin used for treatment were in the susceptible range. Thus, it is clinically important to detect ESBL production by klebsiellae or E. coli even when cephalosporin MICs are in the susceptible range (<or = 8 microg/ml) and to report ESBL-producing organisms as resistant to aztreonam and all cephalosporins (with the exception of cephamycins).

Adolescent↗

PubMed2001

Changes in K value and microorganisms of tilapia fillet during storage at high-pressure, normal temperature.

This study determined the effect of high-pressure, normal temperature (25 degrees C) storage on tilapia fillets. After pressurization, the fillets were stored at normal condition (1 atm [1 atm = 101.29 kPa] and 25 degrees C) for 12 h to evaluate the changes of microbes and K value. The fillets stored at 2,000 atm for 12 h still kept the K value, a freshness index that represents putrefaction with the value beyond 60%, still below 40%, and the K value of the meat without pressurization was up to 92%. Total plate counts of the fillets stored at below 1,000 atm for 12 h were maintained at the value of 4.7 log CFU/g of meat, which was similar to the initial level. However, the counts were obviously decreased to about 2.0 log CFU/g of meat for the fillets stored at above 2,000 atm. The same effect was obtained for psychrophilic bacteria. Enzymes and microbes reactivated apparently after 12 h of normal condition storage of mild pressurized fillets. The study demonstrates that high-pressure storage can inhibit the putrefaction of tilapia meat but no longer after that.

Adenosine Triphosphate↗

PubMed2001

Clostridium bacteremia: emphasis on the poor prognosis in cirrhotic patients.

Bacteremic episodes caused by anaerobes are unusual and the clinical importance of Clostridium bacteremia remains unclear. This retrospective case study examined the risk factors among a group of patients who developed Clostridium bacteremia. Medical records from 73 episodes of clostridial bacteremia in 73 patients treated in a medical center during an 11-year period were reviewed. Of all episodes, 96% were community-acquired. Twelve percent of patients had polymicrobial bacteremia, with Escherichia coli being the most common accompanying bacterium. Diabetes mellitus (26%) and liver cirrhosis (25%) were the most common underlying diseases. The most common etiological organisms were Clostridium perfringens (77%), Clostridium bifermentans (9%), and Clostridium septicum (4%). Only one patient with C. septicum bacteremia had a histocytotoxic infection, which was a fatal gas gangrene. Univariate analysis of data from patients with monomicrobial Clostridium bacteremia revealed that younger age (age < 65 years), underlying liver cirrhosis, and presence of septic shock at initial presentation were associated with fatality; but only the latter two variables were independently associated with fatality in multivariate logistic regression analysis. Appropriate antimicrobial therapy for monomicrobial Clostridium bacteremia did not significantly affect clinical outcomes, which might suggest that Clostridium species in the bloodstream can be regarded as merely contaminants or transient bacteremia. This suggestion was not supported by the finding that seven of 13 cirrhotic patients with monomicrobial Clostridium bacteremia died of sepsis, of whom six had not receive appropriate antimicrobial therapy. Therefore, the clinical importance of Clostridium bacteremia should be interpreted with caution because of its high risk of mortality in susceptible hosts, particularly cirrhotic patients, who do not receive appropriate therapy timely.

Adult↗

PubMed2001

Decreased predominance of papG class II allele in Escherichia coli strains isolated from adults with acute pyelonephritis and urinary tract abnormalities.

PURPOSE: We compared the genotypes of fimbriae or adhesions of Escherichia coli causing acute pyelonephritis in adults with and without urinary tract abnormalities. MATERIALS AND METHODS: We studied a total of 92 E. coli strains isolated from 54 patients with acute pyelonephritis and a normal urinary tract, and 38 with urinary tract abnormalities. Of those with urinary tract abnormalities 13 with moderate to severe hydronephrosis were also considered a separate group for the purpose of analysis. The genes of 7 known fimbriae or adhesins of E. coli were detected by the polymerase chain reaction, including the papG class I to III alleles (PapG adhesins of P-fimbriae), sfa/foc (S-/F1C-fimbriae), fimH (type 1 fimbriae), and afa (afimbrial adhesin). Virulence genes associated with APN were identified by comparing the prevalence of each of these 7 genes in E. coli strains from 54 patients with acute pyelonephritis with a normal urinary tract to the prevalence in the strains from 37 patients with acute cystitis using univariate and multivariate analysis. Differences in the prevalence of the genes associated with acute pyelonephritis and the incidence of underlying illness were then compared in the 3 acute pyelonephritis groups. RESULTS: On univariate and multivariate analysis the papG class II allele was the only virulence gene associated with acute pyelonephritis (p <0.0001 and 0.001, respectively). No significant difference was noted in the prevalence of underlying medical disease in the 3 acute pyelonephritis groups. The papG class II allele was significantly less predominant in E. coli strains isolated from acute pyelonephritis cases with versus without urinary tract abnormalities (76% versus 93%, p = 0.03). The incidence of the papG class II allele in patients with urinary tract abnormalities and moderate to severe hydronephrosis was less than in those without urinary tract abnormalities (69% versus 93%, p = 0.04). CONCLUSIONS: Our results imply that the papG class II allele has an important role in E. coli infection in patients with acute pyelonephritis and a normal urinary tract, while urinary tract abnormalities and/or obstruction may permit ascending infection of E. coli strains with lower adhesive ability.

Acute Disease↗

PubMed2001

Klebsiella pneumoniae psoas abscess: predominance in diabetic patients and grave prognosis in gas-forming cases.

Seven cases of psoas abscess caused by Klebsiella pneumoniae were observed at the National Cheng Kung University Hospital within a period of 4.5 years. These cases constituted 25% of a total 28 episodes of non-tuberculous psoas abscess, ranking second to those caused by Staphylococcus aureus (8 cases). Eight cases of psoas abscess caused by K. pneumoniae were identified from Medline, and 5 of which were reported from Taiwan. Of these 8 cases, 1 neonatal case was excluded, and the remaining 7 adult cases were combined with the 7 cases in this series for analysis. The mean age was 53.8 years, and diabetes mellitus was the most common underlying disease. Fever and pain on the flank and back area were the common findings. The interval between the onset of symptoms and diagnosis ranged from 1 to 60 days. The most common sites of concurrent infection were the urinary tract (6 cases; 43%) and bone (3 cases; 21%). All patients received percutaneous or surgical drainage in addition to antibiotic treatment. Gas formation was present in 5 of the 12 patients recorded, and 4 of them died during hospitalization. Only 1 patient had a metastatic infection with osteomyelitis of the left radius and right humerus; he had experienced 5 episodes of recurrent K. pneumoniae infections in different sites. We concluded that K. pneumoniae should be considered as an important endemic pathogen of psoas abscess in diabetics in Taiwan. The high mortality rate in the gas-forming cases should also be highlighted. Early recognition, empiric antimicrobial coverage for K. pneumoniae, and aggressive drainage or debridement are indicated in these patients.

Adolescent↗