Carbapenemase Production of Clinical Isolates Acinetobacter baumannii and Pseudomonas aeruginosa from a Bulgarian University Hospital.

BACKGROUND: Production of Bla OXA-23, OXA-24, OXA-58 and hyperexpression of OXA-51 due to ISAba1 insertion sequence are the leading causes of carbapenem resistance in Acinetobacter baumannii. The loss of OprD transmembrane protein and the overexpression of some effl ux pumps are considered to be the main factors for carbapenem resistance in Pseudomonas aeruginosa whereas metallo-enzymes' production has a secondary role. AIM: Тo examine the carbapenem resistance due to carbapenemase production among clinically signifi cant Gram-negative non-fermenters from St George University hospital, Plovdiv: A. baumannii and P. aeruginosa. MATERIALS AND METHODS: Forty three A. baumannii and 43 P. aeruginosa isolates, resistant or with intermediate resistance to imipenem and/or meropenem were included in the study. They were collected from patients admitted in 14 various hospital wards between 2010 and 2014. Both phenotypic and genetic methods were used for identifi cation and antimicrobial susceptibility testing. RESULTS: All A. baumannii demonstrated carbapenemase production determined by a modifi ed Hodge test whereas P. aeruginosa isolates did not show this phenomenon. OXA-23 genes were determined in 97.7% (42 out of 43) of A. baumannii isolates indistinguishable from the sequence of the classical ARI-1 gene. OXA-24, OXA-58 and overexpression of OXA-51 were not registered in any of the isolates. All P. aeruginosa were negative for blaVIM and blaIMP genes. CONCLUSION: The leading cause of carbapenem resistance in A. baumannii isolates from our hospital is the carbapenemase production due to the expression of OXA- 23 gene, whereas in P. aeruginosa - the loss of transmembrane OprD protein and the effl ux pumps' hyperexpression are suspected to be the main mechanisms.

Evaluation of antimicrobial resistance among Salmonella and Shigella isolates in the University Hospital "St. George," Plovdiv, Bulgaria.

The aim of this work is to study the epidemiology and antimicrobial resistance to the most commonly used antibiotics for the treatment of acute gastroenteritis caused by Salmonella and Shigella at the largest Bulgarian hospital-University Hospital "St. George," Plovdiv-for the period 2009-2013. Two hundred ninety strains were in vitro tested for resistance to 15 antimicrobial agents. The presence of extended-spectrum beta-lactamases (ESBLs) was demonstrated by a variety of specialized tests. For comparison, a collection of 28 strains submitted by the National Reference Laboratory (NRL) "Enteric Infections" at the National Center of Infectious and Parasitic Diseases (NCIPD), Sofia, was also tested for the production of ESBLs. In isolates, phenotypically demonstrated as ESBL producers, polymerase chain reaction (PCR) detection of the genes bla-CTX-M, bla-SHV, and bla-TEM was performed. Among the 290 tested isolates, only two- Salmonella serotype Livingstone and Shigella flexneri-were phenotypically proven to be ESBL producers. Only 4 strains from the collection of 28, submitted from the NRL "Intestinal Infections" in NCIPD, Sofia, were phenotypically confirmed as ESBL producers. The presence of the bla-CTX-M gene was detected in all of the tested strains (4 from NRL, NCIPD, Sofia, and 2 from the University Hospital St. George, Plovdiv), the bla-SHV gene only in strain S. Livingstone from Plovdiv, and the bla-TEM gene in two from Sofia and one (again S. Livingstone) from Plovdiv. In conclusion, Salmonella and Shigella isolates from patients hospitalized at the University Hospital St. George, Plovdiv, with acute gastroenteritis demonstrate good susceptibility to the most commonly used antibiotic agents, including azithromycin.

Study on anti-inflammatory and immunomodulatory effects of clomipramine in carrageenan- and lipopolysaccharide-induced rat models of inflammation.

The aim of the present study was to evaluate the anti-inflammatory effect of clomipramine in carrageenan- and lipopolysaccharide-induced (LPS-induced) models of inflammation by investigating the changes in serum levels of the pro-inflammatory cytokine TNF-α and the anti-inflammatory cytokines IL-10 and TGF-ß after single and repeated administration of the drug. In order to study the effect of single and repeated doses of clomipramine on carrageenan-induced paw oedema, male Wistar rats were divided in five groups (n = 8): control, positive control group and three experimental groups treated with 5, 10 and 20 mg/kg bw clomipramine, respectively. The effect of single and repeated doses of clomipramine on serum cytokine levels was studied as animals were divided in four groups: two control groups treated with saline and two experimental groups treated with clomipramine 20 mg/kg bw. Carrageenan and LPS were injected immediately after clomipramine or saline injection. Serum cytokine concentrations were tested by enzyme immunoassay. Following acute administration only the highest dose that was used inhibited the carrageenan-induced inflammation. Oedema inhibition was observed with 5, 10 and 20 mg/kg bw clomipramine after repeated administration. Single and repeated administration of clomipramine at a dose of 20 mg/kg bw did not significantly change the serum levels of TGF-1ß, IL-10 and TNF-α when compared to the controls in carrageenan-induced inflammation. Following LPS-induced inflammation clomipramine significantly increased the serum levels of TGF-1ß after repeated administration and decreased TNF-α in rats after single-dose and repeated pretreatment with 20 mg/kg bw clomipramine. A significant increase in the levels of IL-10 in relation to this inflammatory model was observed only in single dose treated animals. Clomipramine possesses an anti-inflammatory effect in the carrageenan-induced model of exudative inflammation. In LPS-induced inflammation, clomipramine showed an immunomodulatory effect, decreasing TNF-α and increasing TGF-1ß after repeated administration, and increasing IL-10 after a single dose.

A study of chemical composition and antimicrobial activity of Bulgarian propolis.

UNLABELLED: Propolis is a natural product which exhibits pronounced antimicrobial and anti-inflammatory effects. AIM: To analyze the chemical composition and antimicrobial effect of Bulgarian propolis, p-cumaric acid and ferulic acid on certain Gram-positive and Gram-negative microorganisms. MATERIAL AND METHODS: Ethanol extract of Bulgarian propolis (Propolin) and water extract of Bulgarian propolis (Propolstom), ferulic acid and p-cumaric acid were used. The chemical HPLC-analysis of propolis was performed with Varian Prostar system. Microbiological tests were done on isolates of Streptococcus beta-haemolyticus, Enterococcus faecalis, Candida albicans and Escherichia coli. Non-treated and ethanol-treated cultures of the corresponding strains were used as controls. Minimal bactericidal and bacteriostatic concentration of Propolin were determined by agar method. RESULTS: The concentration of p-cumaric acid and ferulic acid in ethanol extract of propolis is about 1%. The minimal bactericidal concentration of Bulgarian propolis against Streptococcus beta-haemolyticus is 281 +/- 89.3 microg/ml, against Enterococcus faecalis--3490 +/- 633.1 microg/ml, against Candida albicans--1375 +/- 255.2 microg/ml, and against Escherichia coli--24306 +/- 1706.4 microg/ml. The minimal bactericidal concentration of p-cumaric acid and ferulic acid against Streptococcus beta-haemolyticus is 212 +/- 6.5 microg/ml and 208 +/- 7.7 microg/ml, against Enterococcus faecalis--3013 +/- 176.6 and 3032 +/- 203.4 microg/ml, against Candida albicans--157 +/- 15.5 microg/ml and 149 +/- 23.2 microg/ml, and against Escherichia coli--798 +/- 7.7 microg/ml and 801 +/- 22.8 microg/ml, respectively. CONCLUSIONS: The phenolic compounds p-cumaric acid and ferulic acid are 10 times less extracted in water extraction than in ethanol extraction. The most susceptible strains to the Bulgarian propolis and phenolic compounds are Streptococcus beta-haemolyticus and Candida albicans and the least affected are Escherichia coli and Enterococcus faecalis.