[Susceptibility to selected coagulase-negative chemotherapeutic agents of methicillin resistant staphylococci isolated from clinical materials in 1997-1998]. / Wrazliwosc na wybrane chemioterapeutyki koagulazo--ujemnych gronkowców opornych na metycyline izolowanych z materialu klinicznego w latach 1997-1998.

The study was aimed at assessment of the sensitivity of methicillin-resistant coagulase-negative staphylococci isolated from clinical material in 1997/1998 to selected chemotherapeutic agents. The investigated material comprised 96 methicillin-resistant coagulase-negative staphylococci from hospital and ambulatory infections isolated during the period from April 1997 to May 1998. Species affiliation was determined by classical identification methods and commercial diagnostic tests for identification of staphylococci. Methicillin resistance was determined by agar disk-diffusion method and screening. Sensitivity to chemotherapeutics was determined by agar disk-diffusion method and agar dilution methods. All the investigated strains were sensitive to nitrofurantoin, furazolidone and vancomycin. To teicoplanin--the second glycopeptide antibiotic--84% strains were sensitive, whereas the percentages of resistant and moderately sensitive strains amounted to 5.2% and 10.4%, respectively. 85% and 82% of coagulase-negative staphylococcal strains were sensitive to fusidic acid and mupirocin. Considerable differences were noted with respect to sensitivity to aminoglycoside group antibiotics. About 35% of strains were sensitive to gentamicin, and 90% sensitive to netilmicin. Ca. 40% of coagulase-negative staphylococci were resistant both to cotrimoxazole and trimethoprim, which, in view of 98% resistance to the second component of cotrimoxazole, may be associated with the activity of only one of the components of the drug--trimethoprim.

[Susceptibility to selected chemotherapeutics of Staphylococcus aureus strains resistant to methycyline isolated from clinical materials in the years 1991-1992 and 1997]. / Wrazliwosc na wybrane chemioterapeutyki szczepów Staphylococcus aureus opornych na metycyline izolowanych z materialu klinicznego w latach 1991-1992 i w roku 1997.

The susceptibility to selected chemotherapeutic agents was determined in 100 strains of Staphylococcus aureus methicillin-resistant (MRSA) isolated from clinical materials in 1991-1992 (50 strains) and in 1997 (50 strains). Two methods were used for the determination: disc method and antibiotic dilution in agar. The minimal inhibitory concentration (MIC) was determined for vancomycin, teicoplanin, furazolidone, nitrofurantoin, ofloxacin, gentamicin, netilmicin and trimethoprim. The concentrations of the chemotherapeutics in the substrate ranged from 0.125 to 512 mg/l. The obtained results served for drawing of the following conclusions: all studied MRSA strains isolated in 1991-1992 and in 1997 were sensitive to glycopeptide antibiotics: vancomycin and teicoplanin, to nitrofurans: nitrofurantoin and furazolidone, and to fusidic acid. MRSA strains isolated in 1991-1992 were sensitive to ofloxacin, but in 1997 about 80% of the strains were resistant to that antibiotic, and this resistance was noted in S. aureus strains with homogeneous resistance to methicillin. Increasing frequency of resistance to mupirocin was found, in 1991-1992 4% of the strains were resistant, and in 1997 the resistance of MRSA to that antibiotic was found in 12%. No changes occurred in the sensitivity of staphylococci to trimethoprim/sulfamethoxazole (cotrimoxazole). About 94% of strains in 1991-1992 and 1997 were sensitive to that drug. The sensitivity to cotrimoxazole is connected with one of its components (trimethoprim), with 94% of MRSA strains sensitive to it.

[Microbial analysis of clinical material taken from patients at the Oncology Center, Maria Sklodowkda-Curie Institute in Warsaw in 1997]. / Mikrobiologiczna analiza materialu klinicznego pobranego od pacjentów Centrum Onkologii--Instytutu im. Marii Sklodowskiej-Curie w Warszawie w 1997 roku.

An analysis was carried out of the microbiological investigations of clinical material samples obtained from the patients of two oncology centres belonging to the Warsaw Oncology Centre. Microorganisms cultured from urine, blood, catheters, smears of wounds and other materials were analysed. From 4839 clinical material samples from the Ursynów centre 1755 bacterial strains were isolated. From 423 samples from the centre in Wawelska Street 171 strains were obtained. In infections of patients from the centres the number of Gram-positive cocci was twice that of Gram-negative rods. In the investigated clinical material S. aureus was the most frequently isolated Gram-positive coccus, while E. coli was the most frequent species among Gram-negative bacteria. In the infections of oncological patients a considerable frequency was noted of yeast-like fungi, especially C. albicans. Particularly disquieting was the increasing number of isolates of C. glabrata and C. krusei strains resistant to fluconazole.

The ultrastructure of Penicillium chrysogenum in the course of benzyl-penicillin biosynthesis.

The find structures of high- and low-yield mutants of Penicillium chrysogenum, producing 100 and 10,000 units/ml of penicillin G, were compared. The cells of both mutants demonstrated a typical eukaryotic ultrastructure. In the cytoplasm nuclei, mitochondira, lipid bodies, endoplasmic reticulum, and Golgi vesicles were observed. In the cells of high-yield mutant, during the biosynthesis of penicillin, the number of lipid bodies decreased. It is possible that the lipids are metabolized in the process of biosynthesis of penicillin. In the cytoplasm more multivesicular bodies and small vesicles, about 40 nm in diameter, could be seen. These Golgi vesicles, present in largest number in cells of high-yield mutant, fuse with the cell membrane and play an important role in the transport of penicillin from the cytoplasm to the cell environment. The cell walls of the high-yield mutant become three times thicker during the antibiotic biosynthesis. No comparable changes were observed in the ultrastructure of the low-yield mutant. The cell wall thickness did not increase, the cytoplasm contained few Golgi vesicles only, and the lipid bodies can be seen in all cells.

The site of benzyl penicillin accumulation in Penicillium chrysogenum.

Benzyl penicillin was localized in cells of Penicillium chrysogenum by means of enzymatical and immunological methods, enabling the determination of minute amounts of penicillin. The reactions were performed on ultrathin sections. They allow to determine the antibiotic inside of the cells. The results indicate that benzyl penicillin is present in the vesicles belonging to the Golgi apparatus. Benzyl penicillin is transported from the cytoplasm outside the cell membrane by the Golgi vesicles.