The first NDM metallo-ß-lactamase-producing Enterobacteriaceae isolate in Poland: evolution of IncFII-type plasmids carrying the bla(NDM-1) gene.

Poland's first Enterobacteriaceae isolate producing the New Delhi metallo-ß-lactamase (NDM) was identified in August 2011. Escherichia coli sequence type ST410 NDM-1 was cultured from a critically ill patient who had been transferred directly from the Congo. The blaNDM-1 gene was carried by conjugative IncFII-type plasmid pMC-NDM (87,619 bp), which showed structural similarity to plasmid pGUE-NDM, which was identified earlier in France in an E. coli ST131 isolate of Indian origin.

[A Polish multicenter survey of antimicrobial susceptibility and prevalence of beta-lactamase production among bacterial pathogens isolated from hospitalized and ambulatory patients]. / Ocena opornosci na antybiotyki i czestosci wystepowania beta-laktamazy wsród szczepów bakterii izolowanych od chorych leczonych w szpitalu i ambulatoryjnie Polskie badania wieloosrodkowe.

The aim of the study was to establish the frequency of occurrence of bacterial pathogens with beta-lactamase activity, and pattern of resistance among aerobic and anaerobic strains isolated from: respiratory tract, urinary tract, skin and soft tissues (hospitalized patients) and throat swabs (ambulatory patients). The study was conducted in 1994 year in 6 bacteriological laboratories in four Polish towns (Warszawa, Kraków, Katowice, Gdansk) according to the protocol. Sensitivity of bacteria was tested by the disc method on the Müeller-Hinton agar or chocolate agar according to NCCLS, activity of beta-lactamase was tested with nitrocephin. A total 2038 clinical strains--1869 aerobic and 169 anaerobic was well-defined and tested for susceptibility to ten antibiotics--amoxicilin, augmentin, ofloxacin, gentamycin, cefradin, erythromycin, cefuroxim, kotrimoxazol, cefalexin and cefaclor. Among the isolated aerobes Staphylococcus aureus (25.1%), E. coli (23.2%) and Haemophilus influenzae (14.0%) were most frequent, and in the group of anaerobes the most frequent were Bacteroides spp (40.8%) We have found 45.8% of all tested aerobic strains with beta-lactamase production, the highest proportion in pathogens isolated from respiratory tract--51.4%, 46.6% from urinary tract, and 48.4% from skin and soft tissues. Among the isolated anaerobic--68.8% of Bacteroides and 28.6% others produced beta-lactamase. Forty percentage of all strains were sensitive to amoxicilin, 70-90% of aerobic bacteria were sensitive to augmentin. Augmentin had a high activity against anaerobic bacteria too. Only a small proportion of the tested aerobic bacteria (12.2%) were resistant to ofloxacin, gentamycin showed a sufficient activity against tested strains (24.4% were resistant). The most frequent pathogen--Staphylococcus aureus was resistant to amoxicilin in 83.1% hospitalized patients, and in 73.9% in ambulatory patients.

Inhibition of vaccinia virus replication in RK-13 cells by N,N'-bis(methylisatin-beta-thiosemicarbazone)-2-methylpiperazine.

N,N'-bis(methylisatin-beta-thiosemicarbazone)-2-methylpiperazine in a 100 mumol/l concentration inhibited the reproduction of vaccinia virus in RK-13 cells by about 90%. This compound (bis-IBTMP) had no influence on virus adsorption and on early stages of virus multiplication, but affected virus reproduction from 12 to 24 hr post-infection (p.i.). The incorporation of 3H-thymidine into infected cells increased during first 10 hr p.i., decreasing gradually afterwards. In the infected cells treated with bis-IBTMP the same tendency was observed up to 10 hr p.i., but later on the incorporation level remained unchanged. The uptake of 14C-amino acids in the presence of bis-IBTMP was reduced both in vaccinia virus-infected and non-infected RK-13 cells.

[Dipyridamole as an inhibitor of vaccinia virus replication]. / Dipiridamol kak ingibitor razmnozheniia virusa vaktsiny.

Dipyridamole in concentration of 25 microM inhibited the multiplication of vaccinia virus in about 90% of cells. In the presence of this substance, [3H]-uptake was sharply reduced both in uninfected and infected RK13 cells, while [14C]-uptake was not inhibited incorporation of [3H]-thymidine and [14C]-amino acids into viral particles. The present findings suggest that the antiviral character of dipyridamole is related with the inhibition of the substrate transport through the cell membrane.

Preparation of rubella virus haemagglutinating antigen by polyethlene glycol precipitation.

Polyethylene glycol (PEG) was used for precipitation of rubella virus haemagglutinating (HA) antigen from the fluid phase of infected Vero cell cultures, maintained with or without calf serum. In both cases potent antigen preparation were obtained. When the antigen was precipitated from serum-containing medium, higher titres were obtained, provided that substrate or final product were treated with Tween 80 and ether. HA antigen obtained by PET precipitation was entirely valuable in the haemagglutination-inhibition test, as compared with antigens prepared by other methods.

Growth of rubella virus in primary rabbit kidney cell cultures maintained with and without calf serum.

Rubella virus growth was tested in primary rabbit kidney cell cultures, maintained with or without calf serum. In fluid phase of the cultures maintained with 1.5% of heat-inactivated calf serum, the infectious virus titers were much higher than in the system without serum. The differences reached 1.5-2.0 log10 TCID50/ml. Virus multiplication curves also ran different courses. In serum-containing system virus titer increased up to the 9th day post infection, while without serum--only up to 4-5 days. The time of appearance and the type of cytopathic effect were not affected by the absence of serum or by its presence in a concentration of 1.5%.