Pylephlebitis Associated with Acute Infected Choledocholithiasis

Pylephlebitis, also called septic thrombophlebitis of the portal vein, is a life-threatening complication of intra-abdominal infection. Although rare, it remains a less recognized entity with a high rate of mortality. We present a 66-year-old man with acute infected choledocholithiasis complicated with Bacteroides fragilis bacteremia. The contrast-enhanced computed tomography scan of the abdomen showed nearly total thrombotic occlusion of the left portal vein. The comprehensive studies for hypercoagulation disorders all yielded negative results. After endoscopic extraction of bile duct stones and broad-spectrum antibiotic therapy, the patient recuperated with complete recanalization of the occluded portal vein. To our knowledge, pylephlebitis associated with acute infected choledocholithiasis has never been reported. This report details the clinical features, radiographic findings, pathogenesis, and treatment of this distinctly unusual manifestation. Early identification of pylephlebitis and underlying intra-abdominal infection can be achieved by exquisite imaging studies with raised awareness in the clinical setting. Eradication of infectious foci and judicious administration of antimicrobials are essential to reduce the catastrophic morbidity and mortality of pylephlebitis.

Characterization of acquired beta-lactamases and their genetic support in multidrug-resistant Pseudomonas aeruginosa isolates in Taiwan: the prevalence of unusual integrons

OBJECTIVES

The present study was conducted to investigate acquired beta-lactamases and their genetic support in 26 Pseudomonas aeruginosa isolates that were resistant to nearly all antipseudomonal drugs from six medical centres in Taiwan.

METHODS

Acquired beta-lactamases and their genetic support were determined by PCR-based strategies.

RESULTS

Four and 16 of the 26 isolates were found to produce VIM-2 and VIM-3 metallo-beta-lactamases (MBLs), respectively, and 1, 1 and 2 isolates produced OXA-17, OXA-10 and PSE-1, respectively. These bla genes are all in class 1 integrons that are probably chromosomally located. The bla(VIM-3)-containing integron, with a deletion between int1 and the bla(VIM-3) structural gene, has six gene cassettes, bla(VIM-3), a probable fosfomycin resistance determinant, aacA4, aacA4, aadB and aacA4. The bla(VIM-2)-containing integron, without detectable 5'-conserved segment, contains four genes cassettes (aacA7-bla(VIM-2)-dhfr-aacA5) and is ended by tniC. The bla(OXA-10)-containing integron includes a catB3 cassette and a fused gene cassette, which is made up of bla(OXA-17) and a novel streptomycin-spectinomycin gene, designated aadA15. The bla(OXA-17)-containing integron has three gene cassettes (aacA4-catB2-bla(OXA-17)) but the 59-base element of the bla(OXA-17) cassette is interrupted by a putative transposase gene. The bla(PSE-1)-containing integron has three gene cassettes, aacA4, an aadA3-related gene designated aadA3b and bla(PSE-1). PFGE revealed genetic diversity among the multidrug-resistant isolates from different hospitals.

CONCLUSIONS

This study demonstrated the high prevalence of VIM-type MBLs and the presence of unusual bla-encoding integrons in multidrug-resistant P. aeruginosa isolates in Taiwan. The spread of bla(VIM-2)-related genes by horizontal transfer might have occurred.

Extended-spectrum beta-lactamases and plasmid-mediated AmpC enzymes among clinical isolates of Escherichia coli and Klebsiella pneumoniae from seven medical centers in Taiwan

Production of extended-spectrum beta-lactamases and plasmid-mediated AmpC enzymes was investigated among 291 Escherichia coli and 282 Klebsiella pneumoniae isolates that showed decreased susceptibilities to extended-spectrum cephalosporins from seven Taiwanese medical centers. CTX-M-type and SHV-type enzymes were the most prevalent extended-spectrum beta-lactamases. CMY-2-like and DHA-1-like beta-lactamases were the most prevalent AmpC-type enzymes.

Calcium effect on fermentative hydrogen production in an anaerobic up-flow sludge blanket system

The effects of calcium ions on a granular fermentative hydrogen production system were investigated in four lab-scale UASB reactors that fed on sucrose (20 g COD/L). The reactors were seeded with anaerobic sewage sludge microflora and operated at a temperature of 35 +/- 1 degrees, pH of 6.7 with hydraulic retention times (HRTs) of 24-6h. The experimental results indicated that calcium ion addition (75 - 150 mg/L) could enhance the granulation and elevate hydrogen production efficiency. However, an overly-high calcium concentration (300 mg-Ca(+2)/L) deteriorated the hydrogen productivity. A calcium concentration of 150 mg-Ca(+2)/L resulted in a peak HP of 3.6 mol H2/mol-sucrose and HPR of 807 mmol-H2/L-d at HRTs of 8 and 6 h, respectively. The EPS concentration of biohydrogenic biomass was higher than that of the aerobic or methanogenic biomass. The protein/carbon-ratio ranged from 0.17 to 0.26%. The multinomial regression analysis shows that the 75 - 150 mg-Ca(+2)/L calcium concentrations and HRT of 6 h were the optimal operating conditions to efficiently produce hydrogen.

Lemierre's syndrome

Lemierre's syndrome is a rare, potentially severe disease consisting of septic emboli from an internal jugular vein thrombus after oropharyngeal infection. We report a 20-year-old man who had a tonsillitis with fever for 3 days. After a 2-day defervescence, fever relapsed as well as painful swelling over the left side of the neck. Computed tomography scan and sonography of the neck revealed thrombosis of left internal jugular vein and swelling of surrounding soft tissue. Chest radiograph demonstrated cavitary infiltrates over the left upper lobe. Septic thrombophlebitis of the internal jugular vein and metastatic pulmonary emboli was highly suspected. Intravenous ceftriaxone and metronidazole were given empirically. Fusobacterium necrophorum was isolated from the blood culture with susceptibility to metronidazole. Complete defervescence and resolution of the neck swelling and pulmonary infiltrates occurred after antibiotic administration for 21 days. Lemierre's syndrome should be considered when encountering a febrile patient with painful neck swelling.

Rapidly progressive necrotizing fasciitis caused by Staphylococcus aureus

Necrotizing fasciitis (NF) is a rapidly progressive life-threatening infection located in the deep fascia, with secondary necrosis of the subcutaneous tissues. Staphylococcus aureus as a single etiologic agent is rare. The pathogenicity of S. aureus infections is related to various bacterial surface components and extracellular proteins. A 56-year-old man developed fever, hypotension, impaired renal and hepatic functions, disseminated intravascular coagulation, and rapidly progressive NF affecting the 4 extremities due to methicillin-susceptible S. aureus (MSSA). The initial presenting symptoms were general weakness and muscular pain over bilateral thighs and left shoulder, and gradual onset of weakness of the limbs. On the third hospital day, multiple red-purplish discoloration spread across the right lower leg and left forearm. Fasciotomy and debridement was performed on the fifth hospital day, and the diagnosis of NF was confirmed. MSSA was the only pathogen isolated from 4 sets of blood cultures taken on admission and cultures of tissues collected during surgical debridement. The disease progressed rapidly over the 4 extremities despite appropriate antibiotic treatment. He recovered after multiple extensive surgical interventions and 8 weeks of intensive medical care. Early diagnosis, intensive surgical intervention, antibiotic treatment and intensive medical care are crucial for a successful outcome in patients with septic shock and extensive NF caused by S. aureus.

Experience of using convalescent plasma for severe acute respiratory syndrome among healthcare workers in a Taiwan hospital

OBJECTIVES

To describe the immunological responses and clinical outcome of coronavirus (SARS) infected healthcare workers (HCW) who had been administered with convalescent plasma as a treatment.

METHODS

Convalescent plasma (500 mL) was obtained from each of three SARS patients and transfused into the three infected HCW. Donors were blood type O and seronegative for hepatitis B and C, HIV, syphilis and human T-cell lymphotropic virus types I and II (HTLV-I and -II). Serum antibody (IgG) titre was >640. Apharesis was performed with a CS 3000 plus cell separator followed by the forming of the convalescent phase plasma. As part of the routine check with donated plasma, the convalescent plasma was confirmed free of residual SARS-CoV by RT-PCR. Serial serum samples obtained from the recipients of the convalescent plasma were collected to undertake real-time quantitative RT-PCR for SARS-CoV for direct measurement of viral concentration. Specific immunoglobulin IgM and IgG concentrations were titrated using an antigen microarray developed in-house.

RESULTS

Viral load dropped from 495 x 10(3), 76 x 10(3) or 650 x 10(3) copies/mL to zero or 1 copy/mL one day after transfusion. Anti-SARS-CoV IgM and IgG also increased in a time-dependent manner following transfusion. All three patients survived. One HCW became pregnant subsequently, delivering 13 months after discharge. Positive anti-SARS-CoV IgG was detected in the newborn. Passive transfer of anti-SARS-CoV antibody from the mother was considered as a possibility.

CONCLUSIONS

All infected HCW whose condition had progressed severely and who had failed to respond to the available treatment, survived after transfusion with convalescent plasma.

Variety of TEM-, SHV-, and CTX-M-type beta-lactamases present in recent clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae from Taiwan

A total of 171 hospitals' isolates of E. coli, K. pneumoniae, and E. cloacae with a minimum inhibitory concentration (MIC) of > or =2 microg/ml for ceftazidime or cefotaxime were evaluated for the production of beta-lactamases. PCR amplification with specific primers for the bla (SHV), bla (TEM), and bla (CTX) genes revealed that a total of 53, 81, and 43 of these genes were amplified, respectively. Sequencing results confirmed that TEM-1, CTX-M-3 and -14, SHV-1, -5, -11, -12, and -33, OXY-1a, and LEN-1 were presented among these isolates. No specific large cluster of isolates carried the same beta-lactamases, indicating the wide diversity of the collected strains. Plasmid spread between E. coli and K. pneumoniae was identified in few isolates. Combinations of TEM, SHV, and CTX beta-lactamase genes, including extended-spectrum beta-lactamase genes, were observed in all three species.

Acute quadriplegia complicating critical illness polyneuropathy in a patient with infective endocarditis: a case report

A 75-year-old woman with infective endocarditis developed critical illness polyneuropathy (CIP) with quadriplegia after cardiac surgery. The quadriplegia resolved gradually after aggressive treatment of the underlying infection and with rehabilitation. However, a MEDLINE search of the English-language literature failed to yield results matching quadriplegia and infective endocarditis. CIP is a complication of septic syndrome and sepsis. This complication has been largely unrecognized in intensive care units owing to difficulties in performing a clinical examination or electrophysiologic studies. Difficulty in weaning from the ventilator is an important early manifestation of CIP. Electroneuromyography (ENMG) should be routinely performed to establish the diagnosis. We suggest that any septic patients with unexplained muscle weakness, paralysis, or difficulty in weaning from the ventilator should be evaluated for CIP.

Etiology of community acquired pneumonia among adult patients requiring hospitalization in Taiwan

BACKGROUND

There has not been a comprehensive multi-center study investigating the microbial profile of community acquired pneumonia (CAP) in Taiwan.

METHODS

A prospective study of adult CAP patients requiring hospitalization between December 2001 and April 2002 was carried out in 13 hospitals in Taiwan. Etiology was determined based on laboratory data from blood and sputum cultures plus serology from paired serum and urine antigen detection tests.

RESULTS

Etiology was assigned to 99 (58.9%) of the 168 patients having the most complete data for etiology determination, with mixed infection in 21 (12.5%) patients. More than half (51.8%) of the patients were>60 years and 63.7% of the patients were males. The most common etiologic agent was Streptococcus pneumoniae (40, 23.8%), the majority (60%, 24 cases) of which was detected by positive urine antigen test. Other common agents included Mycoplasma pneumoniae (24, 14.3%), Chlamydia pneumoniae (12, 7.1%), Influenza A virus (11, 6.5%), Klebsiella pneumoniae (8, 4.8%) and Haemophilus influenzae (8, 4.8%). The prevalence of S. pneumoniae and M. pneumoniae was highest in patients>60 years (25/87, 28.7%), and<44 years (12/59, 19%), respectively; while K. pneumoniae comprised a larger proportion (4/22, 18%) in the 45-59 years group.

CONCLUSIONS

S. pneumoniae was the most common etiology agent in adult patients hospitalized due to CAP in Taiwan and the spectrum of other major pathogens was similar to studies conducted elsewhere in the world. Empiric treatment recommendations developed in other parts of the world may be appropriately adapted for local use after taking into account local resistance profiles. Our data also support the recommendation that urine antigen test be added as an adjunct to adult CAP etiology diagnosis protocol.

Novel SHV-derived extended-spectrum beta-lactamase, SHV-57, that confers resistance to ceftazidime but not cefazolin

A new SHV-derived extended-spectrum beta-lactamase, SHV-57, that confers high-level resistance to ceftazidime but not cefotaxime or cefazolin was identified from a national surveillance study conducted in Taiwan in 1998. An Escherichia coli isolate resistant to ampicillin, cephalothin, and ceftazidime but sensitive to cefoxitin, ceftriaxone, cefotaxime, imipenem, and a narrow-spectrum cephem (cefazolin) was isolated from the urine of a patient treated with beta-lactam antibiotics. Resistance to beta-lactams was conjugatively transferred with a plasmid of about 50 kbp. The pI of this enzyme was 8.3. The sequence of the gene was determined, and the open reading frame of the gene was found to consist of 861 bases (GenBank accession number AY223863). Kinetic parameters showed that SHV-57 had a poor affinity to cefazolin. The K(m) value toward cefazolin (5.57 x 10(3) muM) was extremely high in comparison to those toward ceftazidime (30.9 muM) and penicillin G (67 muM), indicating its low affinity to cefazolin. Although the K(m) value of the beta-lactamase inhibitor was too high for the study of catalytic activity (k(cat)), indicating the low k(cat) of SHV-57, the SHV-57 carrier was highly susceptible to a beta-lactam-beta-lactamase inhibitor combination. Comparison of the three-dimensional molecular model of SHV-57 with that of the SHV-1 beta-lactamase suggests that the substitution of arginine for leucine-169 in the Omega loop is important for the substrate specificity.

High prevalence of phagocytic-resistant capsular serotypes of Klebsiella pneumoniae in liver abscess

To better understand the role of capsular polysaccharide (CPS) K1 or K2 in Klebsiella pneumoniae liver abscess as well as the development of metastasis to eye, neutrophil phagocytosis of 70 CPS isolates including K1 (n = 23)/K2 (n = 10), non-K1/K2 (n = 37) was evaluated by flow cytometry, fluorescence imaging, and electron microscopy. K1/K2 isolates were significantly more resistant to phagocytosis (P < 0.0001) than non-K1/K2 isolates and displayed increased resistance to intracellular killing. Although mucoid phenotype (M-type) K1/K2 isolates were significantly more resistant to phagocytosis (P = 0.0029) than M-type non-K1/K2, no significant difference in the phagocytosis rate was observed between K1/K2 isolates with M-type and non-M-type (P = 0.0924). Mucoidy is an associated factor that was predominant in K1/K2 isolates, but which itself is not an independent influence on phagocytic resistance. The K1/K2 CPS proved significantly more resistant to phagocytosis than non-K1/K2 CPS in liver abscess isolates (P < 0.0001) and non-abscess isolates (P = 0.0001), suggesting that K1/K2 isolates were generally more virulent in both liver abscess and in non-liver abscess conditions. These findings indicate that resistance of CPS K1 or K2 K. pneumoniae to phagocytosis and intracellular killing presumably contributes to their high prevalence in liver abscess and uniquely in endophthalmitis.

Prospective randomized comparison of single-dose versus 1-day cefazolin for prophylaxis in gynecologic surgery

BACKGROUND

The purpose of this prospective, randomized study was to compare the efficacy of single-dose versus 1-day cefazolin prophylaxis for the prevention of postoperative gynecologic infections.

METHODS

From June 2001 to January 2003, 548 patients were randomized to receive either single-dose (1 g of cefazolin intravenously before surgery, 273 patients) or 1-day cefazolin (1 g intravenously before surgery and three more doses every 6 hr after surgery, 275 patients) prophylaxis.

RESULTS

A total of 531 (267 patients in the single-dose group and 264 in the 1-day group) completed the study. Only one of 267 (0.37%) patients in the single-dose group developed a trocar wound infection and one of 264 (0.37%) patients in the 1-day group developed a vaginal cuff infection. Had a single dose of prophylactic antibiotics been administered to all patients, the antibiotic cost would have been reduced by 75-80%.

CONCLUSIONS

The use of single-dose preoperative cefazolin prophylaxis was as effective as four doses of cefazolin for preventing serious infectious morbidity among our patients. Shortening the duration of antibiotics prophylaxis also reduced medical costs and microorganism resistance.

Rapid creation of a temporary isolation ward for patients with severe acute respiratory syndrome in Taiwan

OBJECTIVES

To rapidly establish a temporary isolation ward to handle an unexpected sudden outbreak of severe acute respiratory syndrome (SARS) and to evaluate the implementation of exposure control measures by healthcare workers (HCWs) for SARS patients.

DESIGN

Rapid creation of 60 relatively negative pressure isolation rooms for 196 suspected SARS patients transferred from 19 hospitals and daily temperature recordings of 180 volunteer HCWs from 6 medical centers.

SETTING

A military hospital.

RESULTS

Of the 196 patients, 34 (17.3%) met the World Health Organization criteria for probable SARS with positive results of serologic testing for SARS-associated coronavirus (SARS-CoV), reverse transcriptase polymerase chain reaction (RT-PCR) from nasopharyngeal or throat swabs for SARS-CoV, or both. Seventy-four patients had suspected SARS based on unprotected exposure to SARS patients; three of them had positive results on RT-PCR but negative serologic results. The remaining 88 patients did not meet the criteria for a probable or suspected SARS diagnosis. Of the 34 patients with probable SARS, 13 were transferred to medical centers to receive mechanical ventilation due to rapid deterioration of chest x-ray results, and three patients died of SARS despite intensive therapy in medical centers. During the study period, one nurse developed probable SARS due to violation of infection control measures, but there was no evidence of cross-transmission to other HCWs.

CONCLUSIONS

Despite the use of full personal protection equipment, the facility failed to totally prevent exposures of HCWs to SARS but minimized the risk of nosocomial transmission. Better training and improvements in infection control infrastructure may limit the impact of SARS.

Plasma proteome of severe acute respiratory syndrome analyzed by two-dimensional gel electrophoresis and mass spectrometry

We have investigated the plasma proteome by using 2D gel electrophoresis and MS from patients with severe acute respiratory syndrome (SARS). A complete proteomic analysis was performed on four patients with SARS in different time courses, and a total of 38 differential spots were selected for protein identification. Most of the proteins identified are acute phase proteins, and their presence represents the consequence of serial cascades initiated by SARS-coronavirus infection. There are several proteins that have never been identified in plasma before using 2D gel electrophoresis, among which peroxiredoxin II was chosen for further study by analyzing additional 20 plasma samples from patients with probable and suspected SARS and patients with fever, respectively. The results showed that the level of plasma peroxiredoxin II in patients with SARS is significantly high and could be secreted by T cells. Taken together, our findings indicate that active innate immune responses, along with the oxidation-associated injuries, may play a major role in the pathogenesis of SARS.

Vancomycin-resistant enterococcus (VRE) carriage and infection in intensive care units

From July, 1997, through December, 2001, patients who were admitted to intensive care units (ICUs) were enrolled in the study of vancomycin resistance enterococcus (VRE) colonization. Among 4,538 patients admitted to the ICUs, 363 (8.0%) patients were found to have positive culture of VRE at the day of admission to the ICUs and 453 (10.0%) of patients were negative to the first day of admission but became colonized with VRE during the stay in ICU. Among 816 patients, 9 (1.1%) with VRE isolated from sterile sites were selected for further analysis. Pulsed-field gel electrophoresis (PFGE) revealed a total of four PFGE banding patterns in the colonized and infected Enterococcus faecium isolates. Six of nine 9 were found to have an identical PFGE type Ia, suggesting the circulation of an endemic strain. All of these type Ia isolates also contained two potential virulence genes, the esp and hly genes and were first identified in Asia. After the further typing of 540 isolates that were randomly selected from each month, the endemic strain was not identified before the first patient was colonized and infected with this strain in November, 1998, but was isolated from other ICU patients during each month thereafter throughout the remainder of the study period. Although colonization of VRE is the first step toward infection, a low infection rate was observed, except in patients with prolonged hospitalization and severe illness. Use of the isolation room and reminders regarding hand hygiene failed to prevent the circulation of endemic strain. Thus, the SHEA guideline (Muto et al., Infect. Control Hosp. Epidemiol. 2003;24:362-386) for preventing nosocomial transmission of VRE should be enforced.

Community-acquired brain abscess in Taiwan: etiology and probable source of infection

Brain abscess is a life-threatening infection caused by spread from infected parameningeal or remote foci. Historically, streptococci have been the predominant organisms reported while brain abscess metastatic from liver abscess caused by Klebsiella pneumoniae has been a more recent emerging problem. This study retrospectively analyzed the characteristics of community-acquired brain abscess admitted during an 11-year period. There were 17 men and 7 women with age from 20 to 82 years (median, 41 years). The most common source of infection was liver abscess, followed by otitic infection and sinusitis. The classic triad of fever, headache and focal neurologic deficit was noted in only 25% of cases. Spread of the abscess to multiple lobes was common (n = 6). The most commonly identified organisms were Streptococcus spp. (n = 7) and K. pneumoniae (n = 5). All 5 cases of K. pneumoniae brain abscess also had concomitant pyogenic liver abscess and 4 of them had diabetes mellitus. In this study, brain abscess was common in young patients and in patients with diabetes mellitus. In Taiwan, Streptococcus spp. and K. pneumoniae are leading etiologies for community-acquired brain abscess. Liver abscess is the most likely source of K. pneumoniae brain abscess.

Resistance rates to commonly used antimicrobials among pathogens of both bacteremic and non-bacteremic community-acquired urinary tract infection

This study examined the distribution of organisms and their antimicrobial resistance in patients admitted due to acute bacteremic and non-bacteremic community-acquired urinary tract infection (UTI). During a period of 1 year and 1 month, a total of 201 patients and 253 bacterial isolates were studied. Fever higher than 38.5 degrees C was significantly more common in the bacteremic group than the non-bacteremic group (68% vs 48%; p<0.05). Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis were the most common organisms isolated. E. coli was the leading pathogen and it was significantly more predominant in bacteremic UTI than non-bacteremic UTI (73% vs 49%; p<0.01). Bacteria other than E. coli (i.e., K. pneumoniae, P. aeruginosa, Proteus spp., Morganella morganii, Enterobacter cloacae, Citrobacter spp., Acinetobacter baumannii, Serratia marcescens, and Providencia spp.) were more common in non-bacteremic UTI than bacteremic UTI (44% vs 22%; p<0.01). E. coli isolated from both bacteremic and non-bacteremic patients had a high rate of resistance to ampicillin (80%), cephalothin (59%), gentamicin (29%), piperacillin (61%), trimethoprim-sulfamethoxazole (56%), amoxicillin-clavulanic acid (34%), and ticarcillin-clavulanic acid (36%). Isolates of P. aeruginosa, K. pneumoniae, and Proteus spp. from the non-bacteremic group showed a higher proportion of resistance to extended-spectrum cephalosporins, aminoglycosides (netilmicin and amikacin) and ciprofloxacin. The emergence of a high rate of resistance to commonly used antimicrobials (ampicillin, cephalothin, gentamicin, trimethoprim-sulfamethoxazole, piperacillin, amoxicillin-clavulanic acid and ticarcillin-clavulanic acid) may have an impact on the antibiotic treatment of patients admitted due to acute community-acquired bacteremic or non-bacteremic UTI in Taiwan. Further studies are needed to clarify the impact of antimicrobial resistance on the outcome in these conditions.

Patient data, early SARS epidemic, Taiwan

Of the first 10 patients in the epidemic of severe acute respiratory syndrome (SARS) in Taiwan, 4 were closely associated with a SARS patient in an airplane. Loose stools or diarrhea, hemophagocytosis syndrome, and high serum levels of interleukin (IL)-6, IL-8, and tumor necrosis factor-a associated with lung lesions were found in all 10 patients.

Ciprofloxacin-resistant Salmonella enterica Typhimurium and Choleraesuis from pigs to humans, Taiwan

We evaluated the disk susceptibility data of 671 nontyphoid Salmonella isolates collected from different parts of Taiwan from March 2001 to August 2001 and 1,261 nontyphoid Salmonella isolates from the National Taiwan University Hospital from 1996 to 2001. Overall, ciprofloxacn resistance was found in 2.7% (18/671) of all nontyphoid Salmonella isolates, in 1.4% (5/347) of Salmonella enterica serotype Typhimurium and in 7.5% (8/107) in S. enterica serotype Choleraesuis nationwide. MICs of six newer fluoroquinolones were determined for the following isolates: 37 isolates of ciprofloxacin-resistant (human) S. enterica Typhimurium (N = 26) and Choleraesuis (N = 11), 10 isolates of ciprofloxacin-susceptible (MIC <1 μg/mL) (human) isolates of these two serotypes, and 15 swine isolates from S. enterica Choleraesuis (N = 13) and Typhmurium (N = 2) with reduced susceptibility to ciprofloxacin (MIC >0.12 μg/mL). Sequence analysis of the gryA, gyrB, parC, parE, and acrR genes, ciprofloxacin accumulation; and genotypes generated by pulsed-field gel electrophoresis with three restriction enzymes (SpeI, XbaI, and BlnI) were performed. All 26 S. enterica Typhimurium isolates from humans and pigs belonged to genotype I. For S. enterica Choleraesuis isolates, 91% (10/11) of human isolates and 54% (7/13) of swine isolates belonged to genotype B. These two genotypes isolates from humans all exhibited a high-level of resistance to ciprofloxacin (MIC 16–64 μg/mL). They had two-base substitutions in the gyrA gene at codons 83 (Ser83Phe) and 87 (Asp87Gly or Asp87Asn) and in the parC gene at codon 80 (Ser80Arg, Ser80Ile, or Ser84Lys). Our investigation documented that not only did these two S. enterica isolates have a high prevalence of ciprofloxacin resistance nationwide but also that some closely related ciprofloxacin-resistant strains are disseminated from pigs to humans.

Persistent retention of acetic acid is associated with complete tumour necrosis in patients with hepatocellular carcinoma undergoing percutaneous acetic acid injection

BACKGROUND

Ultrasound (US)-guided percutaneous acetic acid injection therapy (PAIT) is effective for patients with hepatocellular carcinoma (HCC). This study aimed to determine the occurrence and predictive value of persistent intra-tumoral retention of acetic acid after PAIT.

METHODS

We prospectively studied 60 (52 M, mean age 68 +/- 10 years) patients with 72 HCC nodules (45 < or = 3 cm) treated with PAIT. The presence of post-treatment persistent retention of acetic acid, defined as a homogeneous and highly hyperechoid mass in US appearance 3 days after completion of the treatment, was correlated with the treatment response.

RESULTS

The mean size of the treated tumour was 2.9 +/- 1.0 cm (range 1.5-5 cm). Thirty (42%) HCC nodules showed complete tumour necrosis demonstrated by contrast-enhanced dynamic CT. Complete response was found in 22 (69%) of 32 nodules showing persistent intra-tumoral retention of acetic acid (P < 0.001). Small (< or = 3 cm) tumour size was also significantly associated with complete tumour necrosis (P = 0.001). There were no significant differences of the injection volume and treatment sessions between those with and without complete tumour necrosis in either small or large (> 3 cm) HCC (P > 0.1). Multivariate logistic regression analysis showed that persistent retention of acetic acid (odds ratio (OR) 10.4, 95% confidence interval (CI) 3.1-34.7; P < 0.001) and tumour size < or = 3 cm (OR 6.8, 95%, CI 1.8-25.8; P = 0.002) were independent factors predicting complete tumour necrosis.

CONCLUSIONS

The presence of persistent retention of acetic acid is associated with a favourable response and may predict complete tumour necrosis after PAIT.

Community-acquired methicillin-resistant Staphylococcus aureus bacteremia in Taiwan: risk factors for acquisition, clinical features and outcome

The prevalence of community-acquired infection caused by methicillin-resistant Staphylococcus aureus (MRSA) in Taiwan has increased markedly in the past decade. This study investigated the risk factors for acquisition, the clinical features, and the outcome of community-acquired MRSA bacteremia. Data were collected from records of 86 patients with community-acquired S. aureus bacteremia admitted to a tertiary teaching hospital in Taipei from January 1994 to December 1999. MRSA accounted for 26% (22/86) of isolated pathogens. Over 90% of patients with S. aureus bacteremia had one or more underlying diseases. Significantly more patients with MRSA bacteremia [vs methicillin-susceptible S. aureus (MSSA) bacteremia] had congenital and valvular heart diseases (18% vs 0%, p=0.004), an initial presentation of acute respiratory failure (32% vs 11%, p=0.022), an implant as a portal of entry (9% vs 0%, p=0.014), and mortality (41% vs 20%, p=0.05). Acute Physiology and Chronic Health Evaluation (APACHE) III score was significantly higher in patients who died than in patients who survived in both the MRSA and MSSA bacteremia groups. Inappropriate treatment was more frequent in patients with MRSA bacteremia than in MSSA bacteremia. When a Gram-positive coccemia is initially noted in a patient with high APACHE III score and/or acute respiratory failure, early and aggressive treatment including glycopeptide should be considered.

Mutations of the rpoB gene in rifampicin-resistant Streptococcus pneumoniae in Taiwan

OBJECTIVE

To determine the mechanism of rifampicin resistance in Streptococcus pneumoniae in Taiwan.

METHODS

Rifampicin resistance was investigated with respect to the rpoB gene in 23 invasive S. pneumoniae isolates collected from 1996 to 2001. PCR and molecular typing were used for genetic and epidemiological analyses. Transformation was used to determine the functional gene for resistance.

RESULTS

Twenty-two of 23 isolates carried at least one mutation at either cluster I or III of rpoB; the most frequent mutation found in 21 isolates (91%) was histidine (H499) to asparagine or tyrosine at position 499, followed by isoleucine to valine (I624V) at position 624 in 16 isolates (70%), tyrosine to phenylalanine (Y589F) at position 589 in 14 isolates (60.9%) and isoleucine to valine (I608V) at position 608 in 13 isolates (56.5%). Less-frequent mutations were also identified: D489V, R597F, N623E, N623S, N669D, Q671K, Y674F and A683V. High-level rifampicin resistance was observed in isolates with a mutation at position 499 or 489. Mutations other than at position 499 or 489 played little role in or had no relation to rifampicin resistance. No dominant epidemic strain was observed with ribotyping, multilocus sequence typing, or serotyping.

CONCLUSIONS

Rifampicin resistance among multidrug-resistant S. pneumoniae in Taiwan was mostly caused by rpoB mutations.