Search

Objective: To assess the relevance of urine test (UT), urine culture (UC) and stone culture (SC) for postoperative infections and to investigate the optimal perioperative antibiotic treatment strategy in association with percutaneous nephrolithotomy (PCNL) in patients with renal calculi. Materials and methods: Between September 2016 and September 2018 1,060 patients treated with PCNL were included in the study. The results of UT, UC and SC were reviewed. The details of perioperatively administered antibiotics and postoperative infections were recorded. Results: A positive UT was associated with an increased incidence of infection; this was also the case in patients with negative UC (p < 0.05). There was no significant difference in incidence of infection between patients who were given a single dose of antibiotics compared with those given multiple doses when UC was negative, whether UT was positive or negative (all p > 0.05). The incidence of infection was decreased when pre-operative antibiotics were administered according to the sensitivity pattern based on UC (p < 0.05). This outcome was particularly evident when the treatment duration exceeded 7 days (p < 0.05). A positive SC was associated with increased incidence of infection, even if the patient had a negative UC and UT (p < 0.05). The incidence of infection was significantly decreased when antibiotic treatment was administered based on the results of SC (p < 0.05). Conclusion: Pre-operative prophylaxis with a single-dose antibiotic was sufficient in patients with negative UC, whether UT was positive or negative. Pre-operative treatment with antibiotics according to the bacterial sensitivity pattern should be administered for ≥7 days in patients with positive UC. The postoperative antibiotic treatment strategy should be tailored according to the SC results.

Emergence of extended spectrum beta lactamases (ESBLs) producing strains of gram negative bacteria, as one of the leading cause of septicaemia often complicates the clinical and therapeutic outcome. The present study was undertaken to investigate the prevalence of ESBLs in bacteria isolated from neonatal septicaemic cases along with their antimicrobial sensitivity pattern. Blood samples were collected from 243 suspected cases of neonatal septicaemia. Apart from susceptibility testing, all the gram negative isolates were subjected to phenotypic tests for ESBL production. Amongst the positive test samples (n = 115), 84 were gram negative rods. ESBL was detected in 26 (32%) isolates. Results indicate that routine ESBL detection should be made imperative and empirical use of third generation cephalosporins must be discouraged.

One hundred cases of enteric fever in the age group of 6 months to 12 years were analysed with respect to culture sensitivity pattern and treatment outcome. Patients were divided into 5 treatment groups – chloramphenicol, amoxycillin, trimethoprim-sulfamethoxazole + furazolidine, gentamicin + cephalexin and ciprofloxacin. Out of 91 culture positive cases, 100% were sensitive to ciprofloxacin followed by gentamicin (84.9%), cephalexin (83.6%), furazolidine (36.6%), trimethoprim-sulfamethoxazole (34.1%), chloramphenicol (34.0%) and amoxycillin (23.8%). In 60 cases resistant to chloramphenicol, resistance to other drugs varied from 20 to 88.3%. The treatment response was 100% to ciprofloxacin, 72.7% to chloramphenicol, 50% to gentamicin + cephalexin, 38.5% to trimethoprim-sulfamethoxazole + furazolidine and 12.5% to amoxycillin. Out of 48 cases who did not respond to initial regimen, 33 were treated successfully with ciprofloxacin and remaining with other drug regimens. Time taken for defervescence was shortest with gentamicin + cephalexin (4.6±2.0 days) followed by ciprofloxacin (6.1±2.5 days) and chloramphenicol (6.4±3.5 days). There were 3 deaths in this study.

In MRI (Magnetic Resonance Imaging), the signal-to-noise ratio with nuclear magnetic resonance signals received by a surface coil from an excited body is considerably larger than with corresponding signals received by a body coil in the relevant region. The sensitivity pattern of a surface coil is very non-uniform, however. By correction of a reconstructed image from MR signals received by a surface coil by a corresponding image from MR signals received by a body coil, in which event the surface coil has an arbitrary shape and occupies an arbitrary position with respect to the body, the non-uniformity in the surface coil image is brought back to the uniformity of the body coil image.

Four microbiological acute toxicity screening test methods with Microtox, Spirillum volutans, Pseudomonas fluorescens and Aeromonas hydrophila were compared using solutions of mixed toxic chemicals. Each toxicity screening test appeared to have its own sensitivity pattern and it would appear unwise to try to assess the presence of toxicants in waters or effluents by a single species test. The battery approach, encompassing two or three genera and involving two to four species, is recommended to assess the potential presence of toxicants more thoroughly.

Sputum specimens unlikely to contain M. tuberculosis or specimens artificially created as methylcellulose/egg solution were autoclaved and distributed in batches together with sputum specimens containing viable M. tuberculosis marked with an unusual drug-sensitivity pattern. These specimens were prepared in 1 East African laboratory, divided into aliquots and examined by direct smear and culture in 3 East African laboratories. Independent batches were also prepared and cultured in London. Scanty colonies of M. tuberculosis, always with the characteristic marker sensitivity pattern, were obtained from a proportion of the autoclaved specimens, ranging from 0% of 825 specimens in London to 1.3% of 2165 specimens in Kampala. Transfer of bacilli from positive to negative specimens could therefore account for some of the isolated positive cultures that occur in clinical trials. The occurrence of transfer seemed to be related more to the quality of the technician than to the detail of the technical methods. The African laboratories could be graded in their overall efficiency in smear and culture examination.

Thirteen severely burned patients were treated with amikacin (Amikin) over a two-year period, only one (7-7 per cent) died from his infection. Serum levels were found to be adequate with standard doses in the vast majority of adults and more predictable than with other aminoglycoside antibiotics. In children, greater doses were required than those recommended by the manufacturer. The necessity for monitoring serum levels and renal function in all patients is emphasized. Amikacin is recommended as first choice aminoglycoside where the sensitivity pattern is unknown but gentamicin-resistance is known to occur, or where the organism is known to be resistant to gentamicin, and should also be considered in life threatening infections even with gentamicin-sensitive organisms.

Out of three different methods used for bacteriocin sensitivity typing of Klebsiella strains, the “scarpe and streak” method was the most appropriate tool for its routine use in epidemiologic studies. The method is quite simple, reliable and does not imply any special requirements. Out of 553 Klebsiella strains tested by our set of seven bacteriocins 453 (85%) strains proved to be typable and 100 (15%) nontypable. The number of strains typable by bacteriocins was higher than of those typable by phages. In 14 of 19 outbreaks, the predominance of 1-2 distinct patterns of bacteriocin sensitivity was observed. Two large geographical areas have been delineated by two predominant distinct bacteriocin types of Klebsiella strains, each being observed in a high number of outbreaks as well as in sporadic cases belonging to the same area. Although it was not possible to establish any clear correlation between the pattern of bacteriocin sensitivity and the lysotype or serotype of the strains, the present findings offer strong reason to allow recommendation of the bacteriocin sensitivity pattern as a marker of high epidemiologic significance in monitoring Klebsiella cross-infections. Medical and auxiliary workers could play the role of reservoir to Klebsiella strains and for this reason the hospital personnel has to follow carefully strict procedures for ensuring a valid protection of patients especially when coming into direct contact with neonates, infants and debilitated patients.

The extrapolation of experimental results to amn was studied by cytogenetic bone marrow analysis and micronucleus test in mice, rats and Chinese hamsters. Futhermore, the frequency of chromosomal aberrations was compared with the frequencies of polychromatic erythrocytes containing micronuclei. Cyclophosphamide (CY) was given intraperitoneally at the doses of 5, 10, 20, 40 and 80 mg/kg b.w. to ICR mice and Wistar rats and at the doses of 10, 20, 40, 80, 120 and 160 mg/kg b.w. to Chinese hamsters. Five patients with various types of malignancies until then medically untreated, were i.v. administered 40 mg CY/kg b.w. Bone marrow cells were examined 24 h after the administration. CY induced in all rodents a clear-cut dose-effect relationship in the frequency of breaks, abnormal metaphases as well as in the frequency of micronuclei in polychromatic erythrocytes. When comparing the results in rodents and man at the dose of 40 mg CY/kg b.w., the sensitivity pattern of species was ice > rats > Chinese hamsters > man. From this aspect the possible differences in the metabolism of CY in analysed species are discussed. The presented results tend to a conclusion that micronucleus testing may be a very suitable method used for screening purposes, however, the method of classical cytogenetic analysis, especially the evaluation of breaks, still remains the most exact and reliable technique.

Newly hatched Drosophila males heterozygous for b pr and vg were exposed to 1000 rad and mated daily to fresh b pr vg females. The first crossovers appeared on day 6 (1.5 0 / 00 ). On days 7, 8 and 9 there was a peak incidence of crossovers (between 6 and 10 0 / 00 ). We conclude that these were induced in spermatocytes. There was a decline in incidence over days 10 and 11, with increasing evidence of clustering, to day 12 (2 0 / 00 ) with maximum clustering. Evidence is presented for concluding that days 10 and 11 represent irradiated secondary spermatogonia and day 12 and later, stem cells. Crossovers induced in spermatocytes have lower fertility and viability than those induced in spermatogonia, but this effect is largely due to effects of irradiation on spermatocytes which have been induced independently of the crossover event. After 3000 rad the peak of crossing-over (3%) is obtained on days 10 and 11 (secondary spermatogonia). By studying the induction of crossovers in concurrent experiments at 1, 2, 4 and 6 krad and using different markers ( dp b cn bw ) we have confirmed that the sensitivity pattern is dose-dependent. The explanation for this appears to be that whereas the yield of crossovers in spermatocytes and stem cells is linearly dependent on dose, the induction of crossovers in determinate spermatogonia is proportional to the dose to the power of 3 2 .