Bacterial enteric pathogens in children with acute dysentery in Thailand: increasing importance of quinolone-resistant Campylobacter.

Current data on pathogen prevalence and drug resistance patterns are important for treatment and vaccine-development strategies. An etiologic study of acute bacterial dysentery was conducted in children up to 12 years of age in 2 major hospitals in and around Bangkok. Stool samples or rectal swabs and clinical data were collected. Standard microbiological methods were used to detect Salmonella, Shigella, Campylobacter, Vibrio, Aeromonas and Plesiomonas. Pathogenic E. coli (ETEC, EIEC, STEC) was identified by digoxigenin-labeled probes. A total of 623 cases were enrolled: median age 11.0 months (range 1 month-12 years). At least one bacterial pathogen was isolated in 55% of cases. Campylobacter was the most common pathogen found (28%), whereas Salmonella, Shigella and ETEC were isolated from 18%, 9% and 6% respectively. EIEC, Vibrio and Plesiomonas were isolated from <1% and no STEC was detected. C. jejuni serotypes 36, 4 and 11 were the most common. The mean age of cases with Campylobacter was significantly lower than with Shigella (17.9 vs 52.8 months, p<0.001). Clinical presentations of Campylobacter and Shigella infections were compared: fever (28% vs 37%), abdominal colic (62% vs 80%, p<0.05), vomiting (38% vs 70%, p<0.001) and bloody stools (52% vs 48%). The Campylobacter isolates (80% C. jejuni, 20% C. coli) were 90% resistant to ciprofloxacin but sensitive to macrolides. All the Shigella isolates (70% S. sonnei) were sensitive to quinolones. Our study illustrates the increasing importance of quinolone-resistant Campylobacter and the decline of Shigella in the etiology of dysentery in Thailand. The clinical presentation of campylobacteriosis is similar to that of shigellosis, except that the patients may be younger and there may be less association with colic and vomiting; having fecal leukocytes will be >10/HPF. The use of macrolide antibiotics rather than quinolones would be reasonable in children <24 months of age; fluoroquinolones will be ineffective in at least half of culture-positive cases.

Quinolones and Salmonella septic arthritis.

Salmonella septic arthritis is an infrequent infectious disease but can cause progressive joint destruction resulting in disability. The authors retrospectively reviewed cases with culture proved Salmonella septic arthritis in Srinagarind Hospital, Khon Kaen from 1994 to 2000. There were 23 episodes in 16 cases; all had underlying diseases and a history of steroid abuse or steroid and immunosuppressive therapy. Systemic lupus erythematosus was the most commonly found underlying disease (56%). Salmonella group D and group B were isolated in 13 and 3 cases. Most first episodes had acute onset of monoarthritis. The antibiotics used as initial treatment of the first episodes were beta lactam, cotrimoxazole or quinolones. There were 8 cases with disabled sequelae and 7 cases with relapse. For 13 evaluable first episodes, relapse occurred in 3 cases in the cephalosporin/penicillin and 4 cases in the cotrimoxazole treated group but none in the quinolones. Six relapse cases were treated successfully with quinolones as well as one with cotrimoxazole. Although 5 relapse cases treated with quinolones had previous progressive joint destruction or avascular necrosis, there was no further joint damage after re-treatment with quinolones. In conclusion, quinolones were more effective than beta-lactams and cotrimoxazole for the treatment of Salmonella septic arthritis to prevent relapse and progressive joint destruction.

Clinical and Microbiological Characteristics of Spontaneous Bacterial Peritonitis (SBP) in A Recent Five Year Period / 대한간학회지

BACKGROUNDS/AIMS: Recently, treatment failure with the third generation of cephalosporin was increasingly noted in patients with spontaneous bacterial peritonitis (SBP). We therefore were to evaluate the pattern of antibiotic resistance and its clinical significance. METHODS: We retrospectively analyzed 580 episodes of SBP occurring between 1995 and 1999. There were 87 episodes of SBP in 1995, 222 in 1998, and 271 in 1999. The pattern of isolated organisms and antibiotic resistance, and prognostic factors for survival, were analyzed. RESULTS: Microorganisms were isolated in 41% of total episodes. The three most frequently isolated organisms were E. coli (48%), K. pneumoniae (15%), and Aeromonas (8%). The percentage of resistant strains to cefotaxime (9%, 14%, 32%) and ciprofloxacin (13%, 21%, 32%) significantly increased. The proportion of E. coli producing extended spectrum beta-lactamase (ESBL) also increased significantly (0%, 16%, 33%). The need of secondary antibiotics such as imipenem due to treatment failure was significantly increased from 0% in 1995 to 33% in 1999. Overall in-hospital mortality, however, was not changed (20%, 20%, 24%, respectively). The factor affecting early mortality was renal failure at diagnosis. Prognostic factors for long-term survival were the presence of associated malignancy and ESBL-producing microorganisms. CONCLUSION: Microorgansims resistant to third generation cephalosporin and quinolone were increasingly isolated over the 5 years in patients with SBP. Measures to prevent in-hospital spread of resistant strains and indiscreet use of antibiotics should therefore be instituted.

Decreasing clinical response of quinolones in the treatment of enteric fever.

Multidrug resistant Salmonella infections in India have been encountered since 1990, for which Quinolones were introduced at that time. However, with indiscriminate use of Quinolones, the sensitivity of these drugs when used alone, to treat S. typhi and S. paratyphi are decreasing. From 1997 to 1999, we have noted a gradual decrease in clinical efficacy of Quinolone monotherapy in enteric fever (9.3% in 1997, 20% in 1998 and 34.88% in 1999). Hence we recommend the use of multidrug therapy for Quinolone resistant and complicated enteric fever. Addition of Ceftriaxone and/or Aminoglycoside is recommended.

A retrospective study of infections in neutropenic patients.

This is a retrospective non-randomised study of 37 episodes of infections in neutropenic patients (grades III and IV myelosuppression). The commonest presentation of infection in these patients was fever which was followed by diarrhoea. Infection was documented bacteriologically in 22.6% of episodes and blood culture was positive in 5.5% of episodes only. More than half episodes (56.8%) received quinolone and aminoglycoside combination, 24.3% 3rd generation cephalosporin and aminoglycoside combination and 18.9% combination of quinolone and cephalosporin in cross over. These combinations of antibiotics were successful in 90.5% with quinolone arm, 44.4% with cephalosporin arm and 71.4% in cross over arm. This difference in success was statistically significant and is independent of grade of neutropenia.

Antimicrobial susceptibility of Salmonella typhi to quinolones & cephalosporins.

Antimicrobial sensitivity testing was carried out for 85 isolates of S. typhi by disc diffusion and microbroth dilution for estimation of minimum inhibitory concentration (MIC). The drugs used included amoxycillin, chloramphenicol, ciprofloxacin, ofloxacin, gentamicin, netilmicin, cefuroxime, ceftizoxime, cefoperazone and ceftazidime. Ninety three per cent of our isolates were resistant to amoxycillin and chloramphenicol but total susceptibility was seen to quinolones and aminoglycosides. We also found that 3 per cent of our isolates were resistant to cephalosporins and 23 per cent were in the intermediate range with an MIC of 12.5 or 25 micrograms/ml to these drugs. In spite of decreased efficacy, the strains continued to be fully susceptible to ciprofloxacin as could be seen from the extended dilutions in microbroth dilution tests. The study also revealed that there was lack of correlation between the two methods of sensitivity testing for cephalosporins. We feel that the development of resistance of S. typhi to third generation cephalosporins is a finding worth consideration for further studies.

Comparative efficacy of fluoroquinolones, aminoglycosides, ureidopenicillins & newer cephalosporins against Pseudomonas species.

A total of 74 strains of Pseudomonas aeruginosa and 18 strains of Ps. putrefaciens were tested for sensitivity to 14 different antimicrobial agents. Ps. aeruginosa were mostly sensitive to netilmicin (81%), piperacillin (78%), amikacin (73%), azlocillin (70%), ceftazidime (69%) and pefloxacin (65%). Only 66 per cent strains of Ps. putrefaciens were sensitive to netilmicin, ceftazidime and ceftriaxone. The MIC values of the different drugs for the sensitive strains were comparable with the results of susceptibility testing. The Ps. putrefaciens strains showed greater resistance than Ps. aeruginosa.

Rosoxacin in the treatment of uncomplicated acute gonococcal urethritis.

A total of 112 male patients presenting with acute gonococcal urethritis were admitted to the hospital. The diagnosis was confirmed by smear, culture, oxidase reaction and sugar fermentation tests. The patients were treated with a single 300 mg capsule of rosoxacin. All patients except one showed adequate response to rosoxacin.