[Dysbacteriosis from the standpoint of a microbiologist].

The paper discusses the name "dysbacteriosis" as a microbiological, ecological, and clinical term.

[Automated microbiological systems in a clinical laboratory: advantages and problems associated with their use].

The paper gives the author's experience in using the automated microbiology systems to provide optimal working practice, which includes their choice, laboratory conditions, the purchase of optional equipment, and organizational measures to reduce the time taken for clinicians to have results.

[Antimicrobial drug susceptibility of 365 Streptococcus agalactiae strains isolated in 1999-2006].

In vitro resistance to antimicrobials and its dynamics were evaluated in 365 strains of group B. Streptococcus agalactiae (SGB) isolated in 1999-2006 from female patients in an obstetrics and gynecology clinic of Moscow. Susceptibility to ampicillin, cefazolin, clindamycin, erythromycin, ofloxacin, penicillin, tetracycline and vancomycin was tested with the automatic Vitek 1 system and disk diffusion and double disk method according to CLSI/NCCLS. All the isolates were susceptible to ampicillin, cefazolin, penicillin and vancomycin. Tetracycline, erythromycin, clindamycin and ofloxacin resistance was detected in 78.1, 20.8, 9.0 and 1.1% of the isolates respectively. Three out of 19 strains resistant to erythromycin and susceptible to clindamycin showed inducible resistance to clindamycin in the D test with the Vitek 1 system. No significant differences in the resistance of the SGB strains isolated from diverse clinical materials were observed. Analysis of the resistance of the strains isolated in 1999-2006 demonstrated that resistance to erythromycin increased from 15.6% in 1999-2002 to 24.1% in 2003-2006 (p < 0.05). The tetracycline resistance within the same period lowered from 87.9 to 71.9% (p < 0.01). Therefore, penicillin remained to be the drug of choice for the prophylaxis and treatment of diseases due to SGB. The high of the SGB resistance to erythromycin and clindamycin suggested the use of non-beta-lactam antibiotics by the results of the in vitro susceptibility tests alone. The D-test should be routine in determination of the SGB susceptibility to clindamycin in clinical diagnostic laboratories.

[A case of the long-term carrier state of Pseudomonas aeruginosa on the hand skin of a nurse in a resuscitation department]. / Sluchai dlitel'nogo nositel'stva Pseudomonas aeruginosa na kozhe ruk meditsinskoi sestry otdeleniia reanimatsii novorozhdennykh.

A case of a three-month carrier-state of P. aeruginosa in the hands' skin of a nurse in a newborns reanimation department is described. The carrier state did not seize after the nurse was isolated from work and was related with colonization of the dermal tissue, therefore, it could be detected only after the hands' skin was treated with a detergent solution. The carrier state was arrested after a chemotherapy course with cyprofloxacyn administered both locally and perorally.

[Microbial ecology and a retrospective assessment of the possibility of predicting an outbreak of suppurative meningitis caused by a Serratia marcescens strain in a hospital for the nursing care of premature infants]. / Mikrobnaia ékologiia i retrospektivnaia otsenka vozmozhnosti prognoza vspyshki gnoinykh meningitov, vyzvannoi shtammom Serratia marcescens, v statsionare dlia vykhazhivaniia nedonoshennykh detei.

An outbreak of purulent meningitides in a hospital ward for preterm babies, caused by Serratia marcescens strain of serovar 05/13 with multiple resistance, is described. Data on the results of the long-term observation of the ward showed that during three months preceding the outbreak the consecutive spread of the infective strain and its colonization of the intestine of children occurred. At the moment of the outbreak S. marcescens 05/13 was the dominating intestinal microflora in 37% of children in the ward and constituted 30% of the total aerobic flora in the intestine of the examined children. No S. marcescens strains were isolated from the feces and urine of the medical personnel and mothers. The importance of the observation of microflora colonizing newborn infants in the ward for the evaluation and prognostication of the epidemiological situation is discussed.

[Microbiological control of drug resistance of causative agents in suppurative-septic infections in newborn infants]. / Mikrobiologicheskii kontrol' za lekarstvennoi ustoichivost'iu vozbuditelei gnoino-septicheskikh infektsii novorozhdennykh detei.

Resistance of the main causative agents of purulent septic infections such as pneumonia, meningitis, sepsis, etc. to 11 chemotherapeutic drugs was studied. The pathogens were isolated from autopsies of 203 newborns who died within 1981 to 1987. Among 2978 isolates belonging to Enterobacteriaceae (2466 strains) and Pseudomonadaceae (512 strains) which constituted 88% of all the isolates, strains with multiple resistance predominated: 90% of the strains resistant to 4 or more antibiotics, 77% of the strains resistant to 6 or more antibiotics and 48% of the strains resistant to 8 or more antibiotics. The highest number of the isolates were resistant to 8 and 9 chemotherapeutics (19 and 20%, respectively). 84% of all the isolates belonged to 4 genera: Klebsiella (34%), Escherichia (21%), Serratia (14%) and Pseudomonas (15%). They were characterized by the highest resistance spectra. In all the cases massive colonization of the intestine by the strains with multiple resistance which caused purulent septic infections was observed. The most frequent variants of the drug resistance combination were determined. In the total frequency of the isolate with multiple resistance no significant differences were detected in 1981 and thereafter. In 1986-1987 the frequency of S. marcescens strains increased 3-5 times with simultaneous broadening of their drug resistance spectra. Strains of S. marcescens and K. pneumoniae with multiple drug resistance endemic for definite hospitals were detected.

[The health of newborn infants as a microbiological problem]. / Zdorov'e novorozhdennykh kak mikrobiologicheskaia problema.

The data provided are concerned with the etiological relation of the gravest pyoseptic infections in children of the first months of life, including cases of intrahospital epidemic outbreaks, to the disturbances in microflora formation and colonization of the intestine of the newborn staying at obstetrical and children's hospitals with hospital strains of gram-negative bacteria possessing multiple drug resistance (primarily K. pneumoniae, E. coli, S. marcescens, P. aeruginosa). The microbiological approach to the prevention of pyoseptic infections in children of the first year of life should guarantee that neonates are supplied with sources of normal body microflora and that the control is exercised over the spreading of hospital bacterial strains in obstetrical and children's hospitals.

[Genetic control and the mechanism of the spread of gentamycin resistance among Enterobacteriaceae strains in a hospital]. / Geneticheskii kontrol' i mekhanizm rasprostraneniia ustoichivosti k gentamitsinu sredi shtammov Enterobacteriaceae v statsionare.

Strains of K. pneumoniae belonging to serowars K10, K3, K16 and K62 and two strains of E. coli with multiple drug resistance including newly detected resistance to gentamicin were isolated in succession within the 2-year period of microbiological survey of a hospital department for premature infants. Resistance to gentamicin in the first isolate of K. pneumoniae was due to the non-conjugated plasmid pP12140 with a molecular weight of 15 MD. This plasmid also controlled resistance to streptomycin and sulfanilamides and was physically independent of the other large (about 80 MD) conjugative R plasmid controlling resistance to kanamycin, tetracycline, chloramphenicol and ampicillin. In the strains of K. pneumoniae and E. coli isolated within the following 2 years the marker of gentamicin resistance was included into large (80-120 MD) conjugative R plasmids controlling 6-7 resistance types. DNA of such plasmids was used for transformation of the recipient strain C600 of E. coli. In addition to the transformants with the acquired R plasmids possessing all the resistance markers there were isolated transformants carrying plasmids with the molecular weight of 15 MD controlling resistance to gentamicin, streptomycin and sulfanilamides and capable of self-replication. Analysis of the plasmids with the help of endonucleases EcoR1 and Pst1 revealed complete identity of plasmid pP12140 and similar plasmids of the transformants isolated with the use of DNA of the plasmids of the other K. pneumoniae strains. Marked relation with the plasmids of the transformants isolated with the use of the plasmid DNA of E. coli was also revealed.(ABSTRACT TRUNCATED AT 250 WORDS)

[Polyresistant Enterobacteriaceae strains and their plasmids in a hospital. Medical and theoretical aspects]. / Mnozhestvennoustoichivye shtammy semeistva Enterobacteriaceae i ikh plazmidy v statsionare. Meditsinskie i teoreticheskie aspekty.

The properties and origin of multiple resistant strains of Enterobacteriaceae found in the intestine and nasopharynx of infants admitted to the hospital for premature infants were studied. The strains of E. coli of different serovars isolated at various periods contained similar conjugative R plasmids with a molecular weight of 80 Md belonging to the O incompatibility group controlling resistance to kanamycin and physically independent small plasmids controlling resistance to ampicillin (7 Md) and streptomycin-sulfanilamides (4 Md). Multiple drug resistance in the strains of K. pneumoniae was controlled by single large (100-120 Md) plasmid cointegrates with 6-8 resistance markers. Such cointegrates consisted of several potentially independent plasmids, sometimes dividing on transformation of plasmid DNA of the recipient strains of E. coli K12. The small plasmids controlling resistance to ampicillin and streptomycin-sulfanilamides similar to the respective plasmids of E. coli were the constant components of the plasmids cointegrates. The multiple drug resistance in the above strains was combined with high capacity for colonization in premature infants. The medical staff and mothers were the sources of bacterial strains with single plasmids controlling definite types of resistance. It is suggested that the multiple resistant strains of Enterobacteriaceae are formed in hospital as a result of accumulation of the plasmids or plasmid markers and selection. One of the conditions for successive acquisition of new plasmid markers by definite bacterial strains was their high capacity for colonization in patients, which provided constant contacts and genetic exchange of such strains with a wide range of immigrant strains during colonization in the newly admitted patients.

[Simplified technic of determining the Enterobacteriaceae R-plasmid incompatibility groups suitable for epidemiologic studies]. / Uproshchennaia tekhnika opredeleniia grupp nesovmestimosti R-plazmid Enterobacteriaceae, prigodnaia dlia épidemiologicheskikh issledovanii.

An economical technique for classification of newly isolated R plasmids according to the incompatibility groups with the use of a set of standard test-plasmids is described. The plasmid under study is transferred into E. coli P678 nal-r or C600 rif-r and crossed with the carrier strains sensitive to nalidixic acid and rifampicin of the standard test plasmids. The crossed strains are subjected to mixed cultivation in separate sectors of the dishes with full-value agar. After incubation the bacterial growth is transferred from the sectors with a velvet replicator onto the agar containing rifampicin or nalidixic acid and antibiotics for isolation of transconjugants carrying the standard test-plasmids with different resistance markers in addition to the plasmid being studied. The transconjugants are incubated and additionally twice replicated onto an analogous fresh selection medium with incubation each time for 6-16 hours at 37 degrees C. In case of incompatibility with one of the standard plasmids the plasmid being studied segregates in the transconjugant in the respective sectors during the replications and growth. Segregation of the plasmid is detected when the transconjugant is replicated from the sectors of the third selection dish onto the agar with the antibiotics, resistance to which is controlled by the R plasmid being studied. The growth is determined until the 4th-6th hour of growth at 37 degrees C. After that period retardation in the growth of the transconjugants is most evident in the sector where segregation of the plasmid being studied takes place. The transconjugant growth in the other sectors is used as control.

[Genetic study of plasmid-associated high-frequency mutations to streptomycin resistance in Escherichia coli]. / Geneticheskoe izuchenie assotsiirovannoi s plazmidoi vysokoi chastoty mutatsii k streptomitsinrezistentnosti u Escherichia coli.

Escherichia coli CTR1(RT1)RHfm1) carrying two H-factors and having unusually high frequency of mutation to high level streptomycin resistance is studied. The high frequency of mutation (about 10(-6) to streptomycin resistance is connected with the presence of R factor RHfm1, controlling the resistance to chloramphenicol and low level streptomacin resistance, but not with RT1, controlling the resistance to tetracycline. Spontaneous or ethidium bromide-induced loss of RHfm1 is accompanied by a decrease of the mutation frequency to 10(-9). RHfm1 is efficiently transmissible to other strains at 28 degrees C. The acquisition of RHfm1 by strains of E. coli K-12 ans S. typhimurium LT2 was followed by a 1000--10000-fold increase of the frequejcy of mutation to streptomycin resistance. Some streptomycin resistant mutants were isolated, and chromosome location of the mutations was demonstrated. The streptomycin resistant mutants were unable to transmit high level of resistance to streptomycin with R factor, but only low level one. The loss of RHfm1 by streptomycin resistant mutants was accompanied by the return to the streptomycin sensitivity of the initial R- strans (E. coli K-12 mutants) or by a decrease of the streptomycin resistance to the level, only 2-fold higher than that of R- wild type (E. coli CTR1 mutant). Thus, the mutantions had practically no effect on streptomycin resistance of R- strains, but could lead to high resistance phenotypes in the presence of RHfm1. The mutant loci in all three studied strains were found to be closely linked to the locus "fus" on the genetic map of E. coli.

[Study of the transmissibility of multiple drug resistance and the capacity to ferment lactose in a clinical strain of Kl. pneumoniae]. / Issledovanie transmissivnosti mnozhestvennoi lekarstvennoi ustoichivosti i sposobnosti fermentirovat' laktozu u klinicheskogo stamma pneumonirobial. Kl.

The donor properties of K. pneumoniae PI 220 with multiple drug resistance were studied. It was shown that the above strain carried 2 plasmids, i.e. R-plasmid pPI 220 controling resistance to ampicillin, streptomycin, tetracycline, chloramphenicol, kanamycin and sulphanylamides and plasmid pPI 221 controlling lactose fermentation. Both plasmids can be transfered on conjugation to strain E. coli P678 at a temperture of 28 degrees C at a rate of 10(-5) for pPI 220 and 10(-4) for pPI 221. The drug resistance controlled by pPI 221 was transfered mainly in a "blocks" simultaneously to 6 drugs. Deletion of plasmid pPI 220 was observed rarely. The donor properties of the strain were defined by the conjugative plasmid pPI 220 controlling the self-transfer and mobilization of plasmid pPI 221 incapable of the self-transfer. E. coli P678 (pPI 220) (PPI 221) acquired the donor properties and transfered both plasmids to E. coli J62 on crossing simultaneously at a rate of 10(-2), as well as to S. typhimurium LT2 and P. rettgeri at a rate of 10(-5). In all the recipient strains studied the transfered plasmids were unstable and segregated also simultaneously at a rate being the highest for P. retgari PI 230. The clones with stable preservation of the plasmids could be obtained by selection.