[Generation of Antibiotic Tolerant Bacterial Persisters in Immunocompromized Patients with Hematologic and Malignant Diseases: A New Problem of Health-Care Associated Infections].

Background: Antibiotic tolerance (AT) represents one of the causes of the phenomenon of antibiotic resistance that allows escape of non-replicating metabolically inert microorganisms (persisters) from any antibiotics attack because molecular targets of antibiotics are lacking thereby creating the potential for chronic infections. Aims: Determine the heterogeneity of the strains of opportunistic pathogens E. coli and P. aeruginosa isolates from children with hematologic malignancies containing bacterial persisters that cause the AT phenomenon. Methods: Children with hematological malignancies were divided into 2 groups according to the intensity of antibiotic treatment of infectious complications. Ciprofloxacin-induced persisters were quantitatively determined in the biological materials obtained from sick children. Results: Within the clinical isolates of E. coli and P. aeruginosa, about a third of the strains belong to high-persisting. The numbers of persistent forms of bacteria did not correlate with a minimal inhibitory concentration values ciprofloxacin (r=0.148, n=25, p>0.05). Interestingly, higher level of formation of persistent E. coli and P. aeruginosa, is associated with higher frequencies of infection attacks, massive antibiotic use and unfavorable course of the disease in children. Conclusions: Therefore, detecting the persistent forms of bacterial pathogens including those associated with the health-care associated infection, specifically, in immunocompromised patients, should be included into the contemporary algorithms of microbiological observation and monitoring of patients and intrahospital environment.

[The leading pathways and factors in the transmission of the causative agents of campylobacteriosis under current conditions]. / Vedushchie puti i faktory peredachi vozbuditelei kampilobakterioza v sovremennykh usloviiakh.

The authors have studied the epidemiological importance of different paths and factors of the transmission of causative agents in the foci of campylobacteriosis, as well as the character and frequency of microbial associations detected in cases of campylobacteriosis. The family foci of campylobacteriosis have been epidemiologically studied and the detected factors contributing to contacting campylobacteriosis have been analyzed. As revealed in this study, 41.6% of the foci of campylobacteriosis are linked with the active action of the alimentary factor, while 37.9% of the foci are linked with the factor of everyday contacts. High frequency of microbial associations with Campylobacter has been established (20.8%), which makes it possible for sporadic cases and especially outbreaks of campylobacteriosis to be disguised as other infections.

[The epidemiological characteristics of single cases of campylobacteriosis in urban inhabitants]. / Epidemiologicheskie kharakteristiki edinichnykh zabolevanii kampilobakteriozom gorodskikh zhitelei.

The results of the analysis of the epidemic situation in Campylobacter infection and the epidemiological markers of the strains of the infective agent have demonstrated that Campylobacter infection, registered as single cases among the residents of Vologda, has an epidemic character. An intensive and uncontrolled process among fowl (chickens) and the absence of effective measures of specific prophylaxis make it necessary that a system of hygienic measures be given priority in the complex of measures aimed at the prophylaxis of Campylobacter infection.

[Quantitative correlation of the content of Campylobacter and sanitary indicative bacteria in surface water]. / Izuchenie kolichestvennykh zavisimostei mezhdu soderzhaniem Kampilobakterii i sanitarno-pokazatelnykh bakterii v poverkhnostnykh vodakh.

Quantitative relations between campylobacteria and sanitary indicating bacteria in surface waters were studied. A correlation between numbers of campylobacteria and lactose-positive bacteria was revealed.

[The leading routes and factors in the transmission of the causative agent of campylobacteriosis under current conditions]. / Vedushchie puti i faktory peredachi vozbuditelia kampilobakterioza v sovremennykh usloviiakh.

Epidemiological investigations carried out at the foci of Campylobacter infection in Moscow and the Moscow region in 1987-1990 demonstrated that Campylobacter infection was recently registered as sporadic cases in a few foci. The alimentary route of the transmission of this infection was the main factor of its spread. A high role of everyday contacts in the spread of this infection was noted. The possibility for outbreaks and sporadic cases of Campylobacter infection to be masked by very frequently occurring associations of these bacteria is discussed.

[The epidemiological aspects of campylobacteriosis in children in arid area]. / Epidemiologicheskie aspekty kampilobakterioza u detei v aridnoi zone.

Specific epidemiological features of Campylobacter infection in children in Samarkand Province during the period of 1987-1990 are discussed. The specific proportion of this infection in the total structure of acute enteric infections was, on the average, 8.5%, and Campylobacter carriership among healthy children, 7.0%. Among children with Campylobacter infection, children aged up to 1 year constituted 71.5%. The results of the study of the biological properties of Campylobacter strains isolated from sick and healthy children and their difference from strains isolated in other regions are discussed.

[Risk factors and transmission routes of the causative agents of campylobacteriosis in commercial poultry plants]. / Faktory riska i puti peredachi vozbuditelei kampilobakterioza na promyshlennykh ptitsekompleksakh.

The study, carried out in two regions of the USSR and aimed at estimation of the contamination of products supplied by industrial poultry complexes (IPC), revealed that the contamination of these products was closely related to the Campylobacter contamination of the personnel of IPC. The causes of high Campylobacter contamination of the products of IPC at all technological stages of their production are described. The species, serovars and biovars of Campylobacter strains isolated from different sources were determined, which made it possible to carry out the specific and intraspecific differentiation of these strains.

[The laboratory diagnosis of campylobacteriosis today]. / Laboratornaia diagnostika kampilobakterioza v sovremennykh usloviiakh.

Different conditions necessary for the successful isolation and cultivation of Campylobacter (culture media, inoculation techniques, gas mixtures, etc.) are described. Of these, the most effective conditions and methods, as well as those available for practical health service, have been determined. The main trends in further improvement of the laboratory diagnosis of Campylobacter infection is presented.