Site-directed mutagenesis of the mecA gene from a methicillin-resistant strain of Staphylococcus aureus

The mecA-27r gene from Staphylococcus aureus 27r encodes penicillin-binding protein 2a (PBP2a-27r), which causes this strain to be methicillin resistant. Removal or replacement of the N-terminal transmembrane domain had no effect on binding of penicillin, but removal of portions of the putative transglycosylase domain (144, 245, or 341 amino acids after the transmembrane region) destroyed penicillin-binding activity. The SXXK, SXN, and KSG motifs, present in all penicillin-interacting enzymes, were found in the expected linear spatial arrangement within the putative transpeptidase region of PBP2a-27r. Alterations of amino acids in all three of these motifs resulted in elimination of penicillin-binding activity, confirming their roles in the interaction with penicillin.

The value of captopril renal scintigraphy in assessing the results of percutaneous transluminal renal angioplasty and in following up renovascular hypertension--a case report

Percutaneous transluminal renal angioplasty (PTRA) was performed in a patient with bilateral renal artery stenoses diagnosed noninvasively by captopril renal scintigraphy and confirmed by renal arteriography. The captopril renal scintigraphy parameters returned to normal in correlation with improved blood pressure response fifteen days after PTRA. Five months later hypertension reappeared and the repeated captopril renal scintigraphy suggested left renal artery stenosis. PTRA was repeated and a stent was implanted with reversal of blood pressure, and captopril renal scintigraphy findings returned to normal levels. Six months after second PTRA, the blood pressure increased to hypertensive levels, and captopril renal scintigraphy indicated left renal artery stenosis. The renal arteriography, however, revealed a new stenosis at the left renal artery ostium. The PTRA with a second stent implantation was performed successfully. The captopril renal scintigraphic parameters and the blood pressure were again normalized after the last intervention and remained normal for thirteen months of follow-up.

Quinolones in treatment of human brucellosis: comparative trial of ofloxacin-rifampin versus doxycycline-rifampin

Quinolones have been reported to be active against Brucella species in vitro. In this prospective randomized study, the efficacy and safety of the combination of ofloxacin plus rifampin were compared with the efficacy and safety of doxycycline plus rifampin, both combinations administered for a 6-week period in treatment of brucellosis. Sixty-one patients were enrolled in the study, and 49 had blood or bone marrow cultures positive for Brucella melitensis. Thirty patients received 200 mg of doxycycline plus 600 mg of rifampin once daily, and 31 patients were treated with 400 mg of ofloxacin plus 600 mg of rifampin once daily for 6 weeks. Nine patients in each group had complications of the disease. There was one therapeutic failure in the ofloxacin-rifampin treatment group, and one patient from each group relapsed (3.3% of those in the doxycycline-rifampin treatment group versus 3.2% of those in the ofloxacin-rifampin treatment group). Gastric discomfort was the major side effect observed in 13 patients (43.3%) who received doxycycline plus rifampin, whereas only 2 patients (6.5%) treated with ofloxacin plus rifampin complained of gastric irritation. These results suggest that the combination of ofloxacin plus rifampin administered for 6 weeks is as effective as doxycycline plus rifampin given for the same period, regardless of the presence of complications of the disease.

A gene conferring resistance to vancomycin but not teicoplanin in isolates of Enterococcus faecalis and Enterococcus faecium demonstrates homology with vanB, vanA, and vanC genes of enterococci

We report the sequence of a 630-bp fragment of a gene associated with resistance to high levels of vancomycin in a clinical isolate of Enterococcus faecalis which retained susceptibility to teicoplanin. This gene was similar to the recently sequenced vanB and partially homologous with vanA, but it showed less-marked similarity to vanC. A DNA probe, derived from this polymerase chain reaction-amplified gene fragment, hybridized specifically with genomic DNA from Enterococcus faecium and E. faecalis isolates which were vancomycin resistant (MICs ranged from 8 to 512 micrograms/ml) but susceptible to teicoplanin. Curing of vancomycin resistance was associated with loss of DNA hybridization with the gene probe. Transfer of DNA which hybridized with the probe accompanied transfer of vancomycin resistance to a susceptible recipient strain. Neither curing nor transfer of vancomycin resistance was consistently related to loss or acquisition, respectively, of plasmid DNA.

In-vitro synergy and mechanism of interaction between vancomycin and ciprofloxacin against enterococcal isolates

In-vitro synergy between vancomycin and ciprofloxacin against 44 enterococcal isolates was studied. Synergy occurred in chequerboard MIC determinations with six Enterococcus faecium strains resistant to both vancomycin and ciprofloxacin. The combination was additive for strains susceptible to one or both antibiotics. Time-kill studies involving selected strains with different susceptibility patterns confirmed the chequerboard results. The effect of ciprofloxacin on the induction of vancomycin resistance was compared in two vancomycin-resistant strains of E. faecium. Sub-inhibitory concentrations of ciprofloxacin prevented induction of vancomycin resistance in a ciprofloxacin-resistant strain, but not in a ciprofloxacin-susceptible strain. Membranes isolated from vancomycin-resistant ciprofloxacin-resistant cultures grown with vancomycin and ciprofloxacin at < or = 8 mg/L (0.125 x MIC) expressed a 39.5-kDa membrane protein involved in the expression of vancomycin resistance, but the protein was not detected in membranes from cultures grown in ciprofloxacin 16 mg/L. These findings indicated that a vancomycin-ciprofloxacin combination can be synergic against enterococci resistant to both vancomycin and ciprofloxacin, but would be unlikely to offer any advantage in the treatment of enterococcal infections because of the high concentrations required.

A combined percutaneous-endoscopic method of placing biliary endoprothesis

Endoscopic biliary drainage is an effective and harmless method for biliary obstructions of malign origin. Percutaneous biliary external drainage (PBED) could be attempted if endoscopic drainage is unsuccessful. The percutaneous route has some unwanted effect. We have PBED into internal endoprotheses in 8 malign patients successfully without any complications.

Factors influencing prognosis in bacteremia due to gram-negative organisms: evaluation of 448 episodes in a Turkish university hospital

A total of 448 episodes of bacteremia due to gram-negative organisms observed during the 7-year period between 1983 and 1989 at Hacettepe University Hospitals were studied for evaluating the factors influencing the prognosis. The overall mortality rate was 45.0%. The mortality rates were not significantly different in "rapidly fatal" and "ultimately fatal" disease groups (48.3% and 45.5%, respectively), whereas it was significantly less (34.8%) in the "nonfatal" disease group compared with the "rapidly fatal" category. There were great differences in the mortality rates among different diseases within the same disease category. Shock, multi-organ failure, source of infection, hospital service, appropriateness of antibiotic therapy, and place of acquisition of infection were found to affect prognosis significantly in multivariate analysis. In conclusion, the identification of prognostic factors is a further step for making necessary interventions in reducing the mortality rate associated with bacteremia due to gram-negative organisms. Underlying disease is still an important prognostic factor; however, a new approach is needed for classification of underlying diseases.

Detection of methicillin-resistant staphylococci by using the polymerase chain reaction

A polymerase chain reaction (PCR)-based test was developed for the detection of mecA in staphylococci. To facilitate this process, a rapid cell lysis procedure was established for the release of DNA from staphylococcal strains. Primers based on the DNA sequence of the mecA gene from Staphylococcus aureus were used in PCRs to screen for the presence of this gene in a total of 98 staphylococcal isolates. Fifty-one isolates were mecA positive (17 S. aureus strains and 34 coagulase-negative staphylococci including S. epidermidis, S. haemolyticus, and S. simulans). Results obtained with PCRs were generally consistent with those of standard microbiological assays. PCRs designed to detect the femA gene (factor essential for methicillin resistance) revealed the presence of the gene in all S. aureus strains examined regardless of the susceptibility profiles of the strains to methicillin. In contrast, femA could not be detected in coagulase-negative staphylococci by PCR with the same primers. Low-stringency hybridization suggested the presence of a gene structurally related to femA in S. epidermidis and other coagulase-negative staphylococci examined.

HLA B27 and clinical features in Reiter's syndrome

HLA B27 and other clinical findings were investigated in 18 Turkish patients with Reiter's syndrome (mean age 35.8 +/- 8.09). Male/female ratio was 2/1. All 18 patients were seronegative, 12 (66.6%) presenting with an asymmetrical oligoarticular arthritis. Radiological sacroiliitis and enthesopathy was found in 9 (50%) and 7 (45.6%) patients respectively. HLA B27 was present in 11 (61.1%) patients.

Presentation and role of peritoneoscopy in the diagnosis of tuberculous peritonitis

This study represents the clinical and laboratory features of 135 tuberculous peritonitis cases in whom peritoneoscopic investigation was used routinely. Disease was more common in women than men (1.5:1) and was most frequently encountered in the third and fourth decades in life. The most common presenting symptoms were abdominal distension (96%), abdominal pain (82%), weight loss (80%), weakness (76%), loss of appetite (73%) and fever (69%). The most common physical findings were ascites (96%), fever (75%) and abdominal tenderness (43%). One hundred and twenty-nine cases (95.5%) showed exudative type tuberculous peritonitis with variable amounts of ascites and filmy adhesions. In six patients (4.5%) the disease was of the plastic (dry) type. Peritoneoscopic investigations of 139 patients suggested tuberculous peritonitis but four cases showed histologically proven malignancy (3%). Laparoscopic diagnoses of the remaining cases were confirmed by histology (97%). The laparoscopic appearance of scattered yellowish-white nodules, approximately 1-5 mm in size, on the peritoneal surfaces, and filmy adhesions were suggestive of tuberculous peritonitis. A non-fatal colon perforation occurred as a major complication. After antituberculous therapy patients were followed for at least 1 year. Peritoneoscopy with simultaneous biopsy is the ideal and most accurate diagnostic modality in the diagnosis of tuberculous peritonitis.

Long-term oral ciprofloxacin in the treatment of prosthetic valve endocarditis due to Pseudomonas aeruginosa

Prosthetic valve endocarditis caused by Pseudomonas aeruginosa is refractory to medical treatment alone and early valve replacement is necessary. We describe a 40-year-old patient in whom endocarditis developed in the early postoperative period, and reoperation was not considered feasible. Ciprofloxacin was administered orally in order to suppress bacteremia for 36 months. Long-term oral ciprofloxacin may provide an opportunity in the treatment of prosthetic valve endocarditis caused by Ps. aeruginosa in patients who are unfavorable candidates for reoperation.

[An epidemiologic study of the antibiotic susceptibility of bacteria isolated from patients with urinary tract infections]

This epidemiological Study is held in Sağlik Sosyal Yardim Bakanliği--Hacettepe Universitesi Tip Fakültesi Cubuk Research and Training area to find out the prevalence of urinary tract infections and to determine the antibiotic susceptibility of the causitive organisms. The prevalence of urinary tract infections in the area is 10%. E. coli is the most frequently isolated bacterium (40%). Amikacin, Cephotaxime, and Ofloxacine are the most effective antibiotics.

[Single-dose amoxicillin, TMP-SMX and ofloxacin therapy in lower urinary tract infections]

In this study the results of single-dose amoxicillin TMP-SMX, and ofloxacin therapy in ürinary tract infections have been presented. The study is held in Sağlik Sosyal Yardim Bakanliği - Hacettepe Universitesi Tip Fakültesi Cubuk Study Group Research and Training Hospital. The treatments were successful in 33% of 15 women treated with single-dose oral amoxicillin, in 60% of 15 women treated with 2 tablets DS single-dose TMP-SMX and 100% of 20 women treated with 400 mg oral single-dose ofloxacin.

Plasma trivalent chromium, glucose tolerance and insulin secretion in juvenile- and adult-onset diabetes mellitus

The relation between plasma trivalent chromium (Cr3+), glucose tolerance and insulin secretion was studied in healthy volunteers and in patients with juvenile- or adult-onset diabetes mellitus. Cr3+ levels before and during the oral glucose tolerance test were not significantly different in the three groups, whereas glucose tolerance and insulin secretion were impaired in the diabetics. Our results indicate that plasma Cr3+ behavior does not reflect impairment of glucose tolerance and insulin secretion in diabetes mellitus.

Microbodies in Germinating Fern Spores: Evidence for Glyoxysomal Activity

Enzymes of the glyoxylate cycle, isocitrate lyase and malate synthase, are active during the germination of spores of the fern Dryopteris filix-mas. Increases in activity of both enzymes are correlated with the breakdown of lipid reserves. The occurrence of these enzymes suggests that the microbodies previously described in these spores are glyoxysomes.