Antimicrobial resistance among respiratory pathogens collected in Thailand during 1999-2000.

A multi-center surveillance study was conducted in Thailand during 1999-2000 to determine antimicrobial susceptibilities among the respiratory pathogens Streptococcus pneumoniae (n = 206), Haemophilus influenzae (n = 305), and Moraxella catarrhalis (n = 39). Of the S. pneumoniae isolates collected, 33.5% were penicillin-susceptible, 27.2% intermediate and 39.3% resistant. Expectedly, resistance rates to beta-lactams were higher among penicillin-resistant (ceftriaxone, 14.8%; amoxicillin-clavulanate, 42.0%; cefuroxime, 100%) than penicillin-susceptible (ceftriaxone, 0%; amoxicillin-clavulanate, 0%; cefuroxime, 0%) isolates. Likewise, azithromycin and clarithromycin resistances were 4.3% and 5.8% among penicillin-susceptible isolates, and 77.8% and 95.1% among penicillin-resistant isolates. All S. pneumoniae remained susceptible to vancomycin and 99.5% were susceptible to levofloxacin. Multidrug resistance (resistance to >3 antimicrobial classes) was present in 25.2% of pneumococcal isolates (n = 52), with resistance to azithromycin, penicillin and trimethoprim-sulfamethoxazole the most common phenotype (40/52 isolates; 77.0%). Among the isolates of H. influenzae, the prevalence of beta-lactamase production was 45.2%. All isolates of H. influenzae were susceptible to amoxicillin-clavulanate, azithromycin, ceftriaxone, cefuroxime and levofloxacin while 49.5% were resistant to trimethoprim-sulfamethoxazole. All 39 isolates of M. catarrhalis produced beta-lactamase. Azithromycin (MIC90, < or = 0.03 microg/ml) and levofloxacin (MIC90, 0.03 microg/ml) were the most active agents tested against M. catarrhalis. The results of this study may serve as a baseline for future studies to monitor antimicrobial susceptibilities among respiratory pathogens in Thailand.

Efficacy and safety of twice daily administration of cefpirome in the empiric treatment of sepsis.

Cefpirome is a fourth-generation cephalosporin with good activity against both gram-positive and gram-negative bacteria. A multicentre trial was performed to study the efficacy and safety of cefpirome 2 g twice daily in the treatment of sepsis. Sixty-three cases were recruited from 10 hospitals from April 1996 to January 1998. Fifty seven cases could be evaluated according to the protocol. The APACHE II score was used to measure severity of illness, with 46.9 per cent of patients having APACHE II score more than 10 and two patients more than 20; both were cured. The most common pathogens were gram-negative bacteria with E. coli predominating 16/40 (40.0%), followed by Klebsiella 8/40 (20.0%). The overall clinical success rates were 54 out of 57 patients (94.7%). In patients with positive blood culture, the clinical cures were achieved for 20/22 (90.9%). Cefpirome showed good efficacy and safety in the empirical treatment of suspected bacteremia or sepsis.

Intravenous followed by oral antimicrobial therapy for staphylococcal endocarditis.

Nine men with ten episodes of staphylococcal endocarditis with valvular vegetation (except one) were treated with intravenous cloxacillin for an average of 10 days and followed by oral cloxacillin or dicloxacillin, both with probenecid, for a total duration of 4 wks. Monitoring of serum bactericidal titers (SBT) showed similar values between the two routes of therapy. All patients were bacteriologically and clinically cured. However, there were 3 recurrences, 2 were drug abusers. One nonabuser had the same staphylococcal species 8 months later. All survived the second episode. This preliminary study supports the contention that intravenous followed by oral therapy for staphylococcal endocarditis may be a viable and a more economical form of therapy.

Streptococcal endocarditis treated with two-week antibiotic regimen: preliminary report of a partial oral regimen.

We reported 18 consecutive patients with penicillin-sensitive streptococcal IE (infective endocarditis). Twelve were successfully treated with a 2-wk course of penicillin G sodium (PGS) and gentamicin, the dosages of which were guided by minimal inhibitory concentration, minimal bactericidal concentration and serum bactericidal titer (SBT), followed by another six who were treated equally successfully with a one week PGS followed by a second week of amoxycillin together with the usual 2 wks of gentamicin. It is believed that oral therapy, after the initial 2-3 days of parenteral antimicrobial, may be adequate for penicillin-sensitive streptococcal IE.

Empirical antibiotic therapy in febrile neutropenic patients with single-daily dose amikacin plus ceftriaxone.

Hematologic malignancies and cancer patients who become neutropenic as a result of disease or myelosuppressive cytotoxic therapy are at a high risk of developing life-threatening infections, and hence empirical antibiotic therapy is administered promptly. We investigated once daily regimen of amikacin, for dose-dependent bactericidal activity and post-antibiotic effects, plus ceftriaxone, with a long-half life to maximise time-dependent bactericidal activity. Microbiologically proven septicemia were 11 out of 49 febrile episodes (22.5%) and 10 (91%) of these were due to gram-negative bacilli, mostly Enterobacteriaceae. The overall success of the regimen was 63.3 per cent of patients, with no significant toxicity. In conclusion, our findings suggest that once-daily administration of amikacin plus ceftriaxone in the initial treatment of febrile episodes in neutropenic patients produces satisfactory results and more cost-effective compared with other antibiotic regimens requiring 3-4 doses a day.

Murine typhus in Thailand: clinical features, diagnosis and treatment.

One hundred and thirty-seven patients with murine typhus were reviewed. A history of direct contact with rats was rare, and none gave a history of flea bite. No seasonal trend was observed. Clinical presentations included fever (100%), hepatomegaly (24%), rash (20%) and non-specific signs. Complications were uncommon but included jaundice, pneumonia, renal insufficiency and meningitis. Only two patients died. A single 200 mg dose of doxycycline significantly shortened the duration of fever: 79% were afebrile in 48 h, compared to 15% of the untreated group.

Sequential intravenous/oral ciprofloxacin in the treatment of severe multiresistant gram-negative infections.

Twenty-one patients with severe multiresistant gram-negative bacillary infections were treated with ciprofloxacin, intravenously followed by oral. The mean duration of therapy was 13 days. Causative organisms were Klebsiella pneumoniae (18 patients), Pseudomonas aeruginosa (2) and Salmonella enteritidis (1). The overall clinical improvement was 85 per cent, with a bacteriologic improvement of 90 per cent. Three patients died, one had fungemia, another had persistent bacteremia, and a third had progressive lung infiltration despite eradication of bacteremia. Superinfections occurred in 2 patients, and the other 2 had colonization of the wounds. It is shown that this treatment is effective and safe for the treatment of severe multiresistant gram-negative infections.

Lung cavities from Pneumocystis carinii in a patient with systemic lupus erythematosus.

A patient with SLE developed pneumonia due to Pneumocystis carinii. The unusual presentation was the multiple lung cavities. There appeared to be a temporal relationship between the lung infection and reducing steroid intake in this patient.

Scrub typhus pneumonitis: an entity which is frequently missed.

Four cases of scrub typhus pneumonitis are reported. Diagnosis was confirmed by positive Weil-Felix OX-K reaction and immunofluorescent antibody test for Rickettsia tsutsugamushi. Two patients presented with atypical pneumonia and two had overwhelming pneumonia resembling adult respiratory distress syndrome. All patients made a full recovery after appropriate treatment.