The using of the polymerase chain reaction for the detection of resistance genes in gram-negative bacteria in routine practice in a pediatric hospital.

Objective - assessment of RT-PCR for the detection of carbapenem-resistance genes in gram-negative bacteria. A total, 499 strains of gram-negative microorganisms isolated in two pediatric hospitals in 2019-2020 were studied. Species identification was performed using MALDI-ToF mass-spectrometry (Bruker Daltonics, Germany). Meropenem and imipenem minimal inhibitory concentration (MIC) was determined by E-test method (BioMerieux, France). The presence of acquired carbapenemase genes of IMP, NDM, VIM, KPC, OXA-48, OXA-23, OXA-40, OXA-58-groups was determined by RT-PCR. Klebsiella pneumoniae (34%), Escherichia coli (4%), Serratia marcescens (6%) and other members of Enterobacterales (6%), also gram-negative non-glucose-fermenting bacteria Acinetobacter baumannii (14%), Pseudomonas aeruginosa (36%) were found among selected strains. Carbapenemase production was found in 385 isolates (77%). The main mechanism determining carbapenem resistance in P. aeruginosa was the production of blaVIM (100%). A. baumanii strains harbored OXA-23 (55%) and OXA-40 (45%) carbapenemases. The major determinant of carbapenem resistance in K. pneumoniae isolates was OXA-48 carbapenemase, detected in 63% strains, 13% of the strains possessed blaNDM-group, 16% isolates had a combination of blaNDM-group and blaOXA-48-like. Carbapenemase of KPC-group was found in 8% K. pneumoniae strains. OXA-48 carbapenemase prevailed (95%) among S. marcescens strains. Most of E. coli isolates harbored metallo-beta-lactamase NDM (89%). Other members of Enterobacterales most often had OXA-48 carbapenemase (57%), 39% of the isolates carried blaNDM-group. In one strain, a combination of blaNDM-group and blaOXA-48-like was discovered. RT-PCR is a fast and reliable method for the detection of acquired carbapenemases and can be recommended for routine use in bacteriological laboratories.

Evaluation of monomeric prolactin level by TRACE method and precipitation with polyethylene glycol.

Prolactin exists in various forms including the monomeric biologically active form (23kDa) and a higher molecular weight form, bound most commonly to IgG, known as macroprolactin (>100kDa). Macroprolactin lacks biological activity and is one of the causes of false-positive results. In Russian Federation the most common method for macroprolactin determination is PEG precipitation test. We had conducted a retrospective analysis of 37 samples of patients with hyperprolactinemia (3 of them were males). The mean age was 30 [25;35] years. Prolactin level was measured by the immunoenzyme method with manual PEG precipitation and TRACE. The mean values found by the immunoenzyme method with manual PEG precipitation were 461,6 [375,0;821,2] mU/l, by TRACE - 449,9 [357,2;749,2] mU/l. The number of patients with normal prolactin levels was 30% (11) confirmed by two methods, high prolactin level at 46% (17). The prevalence of clinical symptoms of hyperprolactinemia was not differ depend the groups. The phenomenon of macroprolactinemia was registered in 32% (12) of patients. In 8 persons of this group normal prolactin level was revealed and in 4 patients hyperprolactinemia was found by TRACE. Measurements of prolactin levels by the TRACE method is useful for correct diagnosis in patients with equivocal results received by traditional method with PEG precipitation.

[Abdominal sepsis and oxidative stress].

INTRODUCTION: Oxidative stress deserves special attention in the pathogenesis of sepsis. MATERIAL AND METHODS: The study included 96 patients with abdominal sepsis caused by advanced suppurative peritonitis and destructive pancreatitis. All patients were divided into 3 groups depending on the severity of sepsis. Level of malondialdehyde (MDA) was determined to evaluate the intensity of lipid peroxidation (LPO). Proteins oxidative modification was assessed according to level of sulfhydryl groups (SH-groups) and carbonyls in proteins. State of anti-oxidant system (AOS) was defined based on activity of catalase, peroxidase, superoxide dismutase and glutathione peroxidase in erythrocytes. RESULTS AND DISCUSSION: There was no relationship between severity of multiple organ failure, MDA concentration, SH-groups and anti-oxidant enzymes levels. At the same time positive correlation between severity of multiple organ failure and carbonyls content in proteins was revealed. CONCLUSION: In surgical patients sepsis develops on background of oxidative stress. Significant reduction of SH-groups in proteins by the moment of sepsis diagnosis is an unfavorable factor for outcome. The degree of multiple organ failure in patients with abdominal sepsis correlates with oxidative injury of proteinic structures.

[Comparative effectiveness of different treatment methods of liver failure].

It was analyzed the results of treatment of 217 patients (139 men, 78 women) with chronic liver failure in case of liver cirrhosis of various etiology for study of degree of hepatic encephalopathyregression. All patients were divided into 3 groups. In the first group the drug therapy was used. In the second group additionallyplasma exchange was performed, in the third group - alsomolecular absorbent recirculating system was used (effectiveness of MARS-therapy).The results showed that the use of extracorporeal treatment techniques can effectively reduce the severity of hepatic encephalopathy in patients with liver cirrhosis. MARS-therapy improved the neurological status of patientsmore significantly in this case. It is considered that the inclusion of MARS-therapy in the combined treatment of patients leads to a significant reduction of hepatic encephalopathyseverity (1-2 points), in comparison with other methods of treatment.