Stress mitigating and growth enhancing effect of dietary tryptophan in rohu (Labeo rohita, Hamilton, 1822) fingerlings.

An experiment was conducted to study the stress mitigation and growth enhancing role of dietary L-tryptophan (TRP) under thermal stress in rohu, Labeo rohita fingerlings for 45 days. Seven hundred and twenty fishes were distributed in three major groups that are ambient temperature (26 °C), 34 and 38 °C in triplicate following a complete randomized design. Acclimation of fishes to 34 and 38 °C over average ambient temperatures were carried out at 1 °C/day. Each group was fed with a diet supplemented with 0, 0.36, 0.72 or 1.42 % L-TRP. Results showed that blood glucose and serum cortisol level were found to be significantly higher (p < 0.05) in the higher temperature groups than the ambient temperature group. Similarly, aminotransferase, lactate dehydrogenase, malate dehydrogenase, CAT, superoxide dismutase activities were found to be significantly higher (p < 0.05) in the control groups (0 % L-TRP) and decreasing activities of these enzymes were observed with the increasing level of dietary L-TRP. In different temperature groups, L-TRP-supplemented groups were found to have higher (p < 0.05) growth, RGR and PER. The results obtained in the present study indicate that dietary L-TRP mitigates thermal stress and enhances growth. From the present study, we can conclude that dietary supplementation of L-TRP at the 0.72 % level in the diet is found to be optimum to reduce thermal stress even up to 38 °C in rohu, L. rohita. The baseline data obtained here could be useful for the farmers to formulate feeds to culture the fish in different agro-climatic zones.

Single-daily ceftriaxone plus amikacin versus thrice-daily ceftazidime plus amikacin as empirical treatment of febrile neutropenia in children with cancer.

OBJECTIVE: Empirical antibiotic treatment for febrile neutropenic patients has been the mainstay of treatment for many years. Beta-lactam antibiotics and aminoglycosides have been the most frequently used drug combination. The purpose of this study was to evaluate the efficacy, safety, tolerance and costs of single-daily ceftriaxone plus amikacin versus thrice-daily dose of ceftazidime plus amikacin. METHODOLOGY: One hundred and ninety-one episodes of fever and neutropenia in 128 patients from October 1997 to December 1998 were included in a prospective, open-label, single-centre study. Patients were randomly assigned to either treatment group and evaluated as successes or failures according to defined criteria. Daily assessments were made on all patients and all adverse events recorded. Univariate and multivariate analysis of outcomes and a cost analysis were carried out. RESULTS: There were 176 evaluable patient-episodes with 51.1% in the single-daily ceftriaxone-amikacin group and 48.9% in the ceftazidime-amikacin group. There were 50 positive blood cultures: 12 Gram-positive bacteria, 33 Gram-negative bacteria and five fungi. Pseudomonas aeruginosa (P. aeruginosa) accounted for 14% of total isolates. The overall success rate was 55.5% in the ceftriaxone group compared to 51.2% in the ceftazidime group (P = 0.56). Mean time to defervescence was 4.2 days in the single-daily group and 4.3 days in the thrice-daily group. There were nine infection-related deaths; five in the single-daily ceftriaxone group. The daily cost of the once-daily regime was 42 Malaysian Ringgit less than the thrice-daily regime. There was a low incidence of adverse effects in both groups, although ototoxicity was not evaluable. CONCLUSIONS: The once-daily regime of ceftriaxone plus amikacin was as effective as the 'standard' combination of thrice-daily ceftazidime and amikacin with no significant adverse effects in either group. The convenience and substantial cost benefit of the once-daily regime will be particularly useful in developing countries with limited health resources and in centres with a low prevalence of P. aeruginosa.

Ceftazidime-resistant Klebsiella pneumoniae bloodstream infection in children with febrile neutropenia.

OBJECTIVES: To evaluate prevalence of ceftazidime-resistant Klebsiella pneumoniae (CRKP) in the pediatric oncology unit of University Hospital, Kuala, Lumpur, and to identify differences between febrile neutropenic pediatric patients with CRKP and ceftazidime-sensitive K. pneumoniae (CSKP) bacteremia. MATERIALS AND METHODS: Febrile neutropenic patients treated between January 1996 and December 1997 at the pediatric oncology unit of University Hospital, Kuala Lumpur, were prospectively studied. Empirical antibiotic therapy consisted of ceftazidime and amikacin. Those who developed K. pneumoniae bacteremia were identified, and clinical features analyzed. Ceftazidime-resistance was documented via disk-diffusion testing. Production of extended-spectrum beta-lactamase (ESBL) was inferred on the basis of synergy between ceftazidime and amoxicillin-clavulanic acid. The different features between the two groups and variables associated with the development of CRKP bacteremia were analyzed using chi-square and t-tests and calculation of odds ratios. A multivariate analysis was used to identify independent factors for CRKP development. RESULTS: Ceftazidime-resistance was seen in 51.6% of all K. pneumoniae isolates, and all these isolates were inferred to be ESBL producers. All isolates were sensitive to imipenem. Susceptibility to gentamicin was 90.5%. The mean continuous hospital stay prior to the detection of bacteremia was 13.7 days overall, but significantly longer in the CRKP group (21.9 d) compared to the CSKP group (4.3 d) (P = 0.003). Children with CRKP were more likely to have received antibiotics in the 2 weeks prior to detection of bacteremia (87.5% of cases) than the CSKP group (20.0% of cases) (P = 0.0008). Sepsis-related mortality was higher in those with CRKP (50.0%) than in the CSKP group (13.3%) (P = 0.02). Patients who did not receive CRKP-directed antibiotics within 48 hours of admission were more likely to have a fatal outcome than those who did (P = 0.009). Logistic regression analysis identified use of third-generation cephalosporins 2 weeks prior to presentation and a hospital stay of 2 weeks or more as independent risk factors for development of CRKP. CONCLUSIONS: More than half of total K. pneumoniae isolated from blood cultures in the unit were ceftazidime-resistant. Children with febrile neutropenia with prolonged hospital stay and recent prior antibiotic exposure are at high risk of developing CRKP bacteremia. Mortality was significantly higher in this group. Early commencement of appropriate antibiotics (e.g., imipenem with or without gentamicin), according to susceptibility study results, may be beneficial in such circumstances.

Epidemiology and molecular characterization of nosocomially transmitted multidrug-resistant Klebsiella pneumoniae.

OBJECTIVES: To describe the epidemiology, antimicrobial susceptibility, genomic profiles, and control of a nosocomial outbreak of multidrug-resistant Klebsiella pneumoniae (MRKP) that occurred in the pediatric oncology unit of the University of Malaya Medical Centre in Kuala Lumpur. MATERIALS AND METHODS: A prospective epidemiologic and microbiologic study was conducted of MRKP isolated from the blood and wound of a boy with necrotizing fasciitis after a 7-day course of ceftazidime and amikacin. In the following 2 weeks, phenotypically similar MRKP were isolated from the blood cultures of four other patients and rectal swabs of another three patients and two liquid soap samples located in the same ward. RESULTS: Antimicrobial profiles demonstrated that all the isolates were resistant to ceftazidime, sensitive to imipenem and ciprofloxacin, and confirmed to be extended-spectrum beta-lactamase producers. Plasmids of varying molecular weights were present in all isolates. In eight of these isolates, which included four from blood, there were common large molecular weight plasmids ranging from 80 kb to 100 kb. Pulsed-field gel electrophoresis analysis using XbaI demonstrated six different DNA profiles, A to F. Profile A was shared by two blood culture isolates and were related by 91%. Profile B was found in one rectal swab isolate and one isolate from liquid soap and were related by 94%. Profile C was shared by one blood isolate and one liquid soap isolate and showed 100% relatedness. Profiles D, E, and F each were demonstrated by one blood isolate and two rectal swab isolates, respectively. These showed only 65% relatedness. CONCLUSIONS: The MRKP strains in this outbreak were not clonal in origin. The decline of the outbreak after 4 weeks was attributed to the reemphasis of standard infection control procedures and the implementation of a program that addressed sites of environmental contamination.