The microbiological characteristics of intestinal dysbacteriosis in children and adults in the city of Moscow

The bacteriological analysis of 302 children has revealed that dysbacteriosis with the increased content of hemolytic Escherichia in the intestine develops more frequently in the presence of the deficiency of bifido- and lactobacteria. The development of other kinds of dysbacteriosis with the increased content of different opportunistic enterobacteria, staphylococci, enterococci and fungi, as well as dysbacteriosis with the decreased content of Escherichia, does not practically depend on the deficiency of bifido- and lactobacteria. In patients with the increased content of Escherichia an increase in the content of opportunistic enterobacteria, staphylococci and fungi is observed more frequently than in patients with the low content of Escherichia.     

Data to substantiate the early immunological diagnosis of dysentery]

The interaction of the whole blood from patients with dysentery and gastrointestinal diseases of non-dysenteric etiology, with the causative agents of dysentery, Sh. sonnei and Sh. flexneri, and saprophytic, staphylococci labeled with radioactive isotopes was studied in vitro. In dysentery an increase in the capacity of the blood for Shigella fixation was observed from the beginning of the disease. During the 1st week of the disease this reaction was strictly specific and accompanied by a decrease in the fixation of staphylococci, but later the reaction became relatively specific. An increase in Shigella fixation occurred considerably earlier than immune antibody formation, as revealed by the indirect hemagglutination test. This research substantiates the possibility of an earlier immunological diagnosis of dysentery as compared with the serological methods.     

肠球菌溶血及非溶血菌株对小鼠巨噬细胞表达TNF-a的影响

【目的】探讨肠球菌溶血菌株及非溶血菌株对小鼠巨噬细胞RAW264.7表达TNF-а的影响。【方法】用多粘菌素B抑制排除内毒素污染对实验的影响。肠球菌溶血菌株、非溶血菌株各11株,以菌/细胞比 30∶1 感染RAW264.7细胞1 h,加入200 mg/mL氨苄青霉素继续培养24 h,分别于感染后3、6、9、24 h,用ELISA方法检测不同观测点细胞培养液中肿瘤坏死因子TNF-a的含量,并用逆转录-聚合酶链反应方法（RT-PCR）比较肠球菌溶血、非溶血菌株感染6 h后TNF-a mRNA表达的差异。【结果】未感染的RAW264.7细胞培养液中检测不到TNF-a。肠球菌溶血株感染组细胞培养上清液中各观测点的TNF-a的平均含量 (pg/mL) 均比非溶血株性组高。经t检验,P<0.01,差别有显著性。RT-PCR法检测其mRNA的表达也有相同结果：TNF-a mRNA在肠球菌溶血株感染细胞中的相对表达量比非溶血株感染的细胞高,经t检验,P<0.05,差别有统计学意义。【结论】肠球菌溶血株比非溶血株更能促进小鼠巨噬细胞RAW264.7产生TNF-а炎症因子。     

Manifestations of the cyclic nature of the epidemic process in dysentery

Different forms of dysentery, especially those caused by Sh. sonnei and Sh. flexneri, have been found to differ considerably in their cyclic recurrence. The development cycles of the epidemic processes of dysentery have an objective character, occur in the presence of any tendencies in the morbidity rate, and depend on the natural factors. Thus, the cycles of increase and decrease in morbidity are 3, 6, 9, 12 years for dysentery caused by Sh. sonnei and 6, 7, 8 years for dysentery caused by Sh. flexneri.     

Characteristics of a Bacteriocin Derived from Streptococcus faecalis var. zymogenes Antagonistic to Diplococcus peumoniae

A bacteriocin-producing strain of Streptococcus faecalis var. zymogenes (E-1) was isolated from clinical material (conjunctiva). The active substance differed from bacteriocins described by other investigators primarily in its spectrum of antibacterial activity, especially by its marked inhibition of Diplococcus pneumoniae. The E-1 bacteriocin also inhibited nonhemolytic strains of enterococci as well as one-third of the Viridans group of streptococcal strains investigated. The degree of inhibition, however, as indicated by the size of the zones against the latter organisms, was significantly reduced. No activity was detected against any of the strains belonging to the following groups of bacteria: hemolytic enterococci, beta-hemolytic streptococci, nonhemolytic streptococci, staphylococci, and various gram-negative species. Similarly, three strains each of Bacillus cereus and Listeria monocytogenes and one strain of Erysipelothrix insidiosa were not inhibited. The bacteriocin was able to diffuse through bacterial membranes as well as cellulose dialyzer tubing. It was inactivated by heating to 80 C for 20 min but resisted inactivation by either trypsin or chloroform.     

Composition of AME encoding gene in Gram positive Cocci--study on spread of aminoglycoside resistance

Aminoglycoside modifying enzymes (AMEs) are major factors which confer aminoglycoside resistance on bacteria. Composition of six genes encoding AMEs (including lately described aph 2"-genes) was investigated by PCR for 16 clinical isolates of Enterococcus faecalis, 16 clinical isolates of coagulase-positive (S. aureus) and 13 clinical isolates of coagulase negative staphylococci (S. haemolyticus, S. epidermidis) collected in Gdańsk region (Northern Poland) in the years 1998-2001. Diversity of AME encoding gene profiles (composition) was used to analyze spread of AME encoding gene among and within studied group of cocci. According to presence of particular genes we distinguish eleven different AME encoding gene profiles: seven profiles were unique for particular species while the most common was shared among S. aureus, coagulase negative staphylococci and enterococci. Regarding profile frequency statistical analysis (Fstat, AMOVA, cluster analysis UPGMA) shows: the difference between S. aureus and enterococci and coagulase-negative staphylococci, lack of difference between enterococci and coagulase-negative staphylococci, higher variability within than between studied species and presence of multispecies cluster. On the basis of the reports about ability of staphylococci to synthesis enterococcal pheromones, this finding lets assume that spread of aminoglycoside resistance gene among gram (+) cocci is limited only by the ability of stains to synthesis or induction of synthesis conjugation protein.     

Intestinal colonization of newborns treated in intensive care units by multiple drug resistant microorganisms

The aim of the study was to examine the digestive tract colonisation of the newborns by multiple drug resistant bacteria during hospitalization. On the day of admission, after 5 days of hospitalization and at the day of discharge swabs from the anus of the 31 newborns hospitalized in OITiPN were taken and cultured on nutrient and selective media for staphylococci, enterococci, gram negative bacilli and fungi. Susceptibility to antibiotics of bacteria was determined, with giving attention to such resistance mechanisms as: methicillin resistant staphylococci (MRS), high level aminoglycoside resistant (HLAR) and vancomycin resistant enterococci (VRE) and the production of extended spectrum beta-lactamases (type ESBL) by gram negative bacilli. On the day of admission in 7 newborns methicillin resistant staphylococci (MRSCN) were grown in 24 no multiple drug resistant bacteria were found. Among those in 23 already after 5 days of hospitalization, colonization by multiple drug resistant strains was determined: coagulase-negative methicillin resistant staphylococci (MRSCN) were found in 16 children, strains of enterococci (HLAR) in 3 newborns and gram negative ESBL (+) bacilli also in 3 cases. On the day of discharge from hospital (after 13-141 days) in 23 out of 24 newborns enteric tract colonization by multiple drug resistant strains was assessed. In the enteric tract of 3 newborns hospitalized up to 2 weeks coagulase-negative methicillin resistant staphylococci (MRSCN) and/or HLAR enterococci were found; gram negative bacilli that produce ESBL appeared in newborns hospitalized for longer than 14 days. They were isolated in 12 out of 21 newborns. Forming of the enteric tract bacterial flora of the long hospitalized newborns depends on the time of hospitalization as well as on the used therapy.     

Opportunistic microorganisms in respiratory tract diseases in patients of the Moscow Province region

The respiratory tract microflora in patients with inflammatory processes of the upper and lower respiratory tracts in the Moscow Province region has been studied. Changes in the microflora were found to occur in patients with pyoinflammatory diseases (PID) of the upper and lower respiratory tracts have been found to occur. Gram-positive cocci, mainly staphylococci and streptococci, were shown to play the leading etiological role in the development of PID. As revealed in this study, the microorganisms detected in the inflammations of the upper and lower respiratory tracts are coagulase-negative staphylococci, mainly S. epidermidis, as well as enterococci and streptococci belonging to the group viridans.     

Some Microbiological Aspects of Staphylococcal Mastitis

(1) Mannitol fermentation is a reasonably reliable method for the detection of coagulase positive staphylococci in milk. This reliability can be improved if mannitol fermentation is carried out under anaerobic conditions.(2) Among hemolytic strains of staphylococci isolated from milk, beta hemolytic staphylococci predominate. Bovine and sheep blood agar plates give similar hemolytic patterns, but the hemolysis is more pronounced on sheep blood agar.(3) Gelatin liquefaction cannot be relied upon for the selection of coagulase positive staphylococci in milk.(4) Urease production is a feature of the majority of coagulase positive staphylococci isolated from milk.(5) Tellurite Glycine agar medium is not satisfactory for the selection of coagulase positive staphylococci in milk.     

Detection and characterization of erythromycin-resistant methylase genes in Gram-positive bacteria isolated from poultry litter

The epidemiology of four erythromycin-resistant methylase ( erm) genes, ermA, ermB, ermC and msrA, was determined in erythromycin-resistant staphylococci, enterococci and streptococci isolated from poultry litter. All isolates were resistant to multiple antibiotics. Southern hybridization indicated that 4 of the 20 staphylococci contained the ermC gene on plasmids: on a 2.2 kb plasmid in Staphylococcus hominis and S. sciuri, on a 6.0 kb plasmid in S. xylosus, and on a 7.0 kb plasmid in S. lentus. In 16 of the 20 staphylococci, the ermA gene was harbored exclusively on the chromosome, as a double chromosomal insert on 8.0 and 6.2 kb EcoRI fragments. None of the staphylococci harbored the msrA gene. Dot-blot analysis indicated that all enterococci and streptococci hybridized with a biotinylated ermB gene probe. Southern hybridization indicated that only 2 of the 19 erythromycin-resistant enterococci contained the ermB gene on plasmids. The gene was localized on 4.0 kb and 5.9 kb plasmids, respectively, in two Enterococcus faecium isolates. Results from our studies indicate that the patterns of occurrence of erm genes, the sizes of the plasmids and the copy numbers of the inserts were different from the existing information on the presence of erm genes in clinical strains of Staphylococcus spp.     

Inhibition of ruminal staphylococci and enterococci by nisin in vitro

A collection of 59 ureolytic and lactic acid-producing ruminal staphylococci and enterococci, isolates from domestic and wild ruminants, were tested for sensitivity or resistance to lantibiotic nisin. All strains tested were sensitive with zones of inhibition, around wells containing 250 μg nisin, from 6 to 26 mm. 74.6% of isolates had zones of inhibition more than 10 mm and 11.1% more than 20 mm. Nisin was more effective against enterococci than staphylococci. Sensitivity of ruminal isolates to nisin may be used to control bacterial growth during the colonization of the rumen or to study the role of antibacterial activity in microbial interactions. Results obtained can be also used in experiments on gnotobiotic animals.     

Use of antibiotic-resistant Bifidobacterium in treating ulcerative-necrotic enterocolitis in young children

Ulceronecrotic colitis in premature children is accompanied by the development of pronounced intestinal dysbacteriosis characterized by a sharp increase in the number of Escherichia, enterococci, staphylococci and the appearance of opportunistic enterobacteria (Klebsiella, Serratia, Citrobacter, Proteus) in large amounts. Clinical convalescence was observed in 2 weeks in children receiving antibiotic-resistant bifidobacteria with antibiotics and in 3-4 weeks in children receiving commercial bifidobacteria with antibiotics, while children treated only with antibiotics showed no signs of clinical convalescence during the whole course of treatment. After the course of treatment the most effective recovery of the intestinal microflora was observed in the group of patients who had received antibiotics in combination with antibiotic-resistant bifidobacteria. It was manifested by a decrease in the number of Escherichia, Klebsiella, Proteus, Serratia, staphylococci and enterococci simultaneously with an increase in the number of endogenous lactobacilli and bifidobacteria. In those children who had received commercial bifidobacteria in combination with antibiotics or had been treated only with antibiotics the process of the recovery of the intestinal microflora was considerably less pronounced than in the patients of the first group; a decrease in the number of Escherichia, Klebsiella, Proteus and Serratia occurred to a lesser extent, and at the same time an essential increase in the number of enterococci and staphylococci was observed. The level of endogenous lactobacilli and bifidobacteria was considerably reduced. Antibiotic-resistant bifidobacteria actively took in the intestine of the patients. On day 5 after the course of treatment was over their level was (4.3 +/- 0.4) X 10(4) cells/g feces.     

Factors Influencing the Occurrence of High Numbers of Iodine-Resistant Bacteria in Iodinated Swimming Pools

It has been shown that, although iodinated swimming-pool waters are usually free from coliform bacteria and enterococci, the total counts frequently become relatively high. Pseudomonas alcaligenes and Alcaligenes faecalis have been shown to account for most of these high counts. It was of interest, therefore, to compare the microbial flora of four alternately chlorinated and iodinated swimming pools. By means of the membrane filter method and suitable selective media, examinations were made for total viable counts, coliform bacteria, enterococci, staphylococci, Streptococcus salivarius, and P. aeruginosa. Colonies also were picked from membrane filters incubated on standard plate count agar and identified. The results showed that, although viable counts were significantly higher during the iodinated periods, the specific types of bacteria determined were either fewer than or the same as in chlorinated periods. During chlorination, the predominant microbial flora consisted of staphylococci and members of the genus Bacillus. During iodination, however, the P. alcaligenes-A. faecalis group accounted for 92 to 99% of the microbial flora. The accumulation of high numbers of these bacteria was shown to be due to their iodine resistance and their ability to grow rapidly in pool water in the absence of free iodine.     

Susceptibility of antibiotic-resistant cocci to biocides

Biocide resistance has hitherto been a poorly studied subject, possibly due to the belief that such resistance was rare and clinically insignificant. Various recent findings, however, have underlined the importance of biocide resistance as a clinically relevant phenomenon. Outbreaks of biocide-resistant organisms in hospitals have been described and the genetic mechanism for resistance to quaternary ammonium compounds (QACs) in Staphylococcus aureus has now been elucidated. Mycobacteria resistant to commonly used endoscope disinfectants are now commonly reported and have caused numerous adverse clinical events. Cross-resistance between triclosan and antituberculous drugs has been demonstrated in other strains of mycobacteria. This is related to a common mechanism of action. The work presented here describes studies into the biocide resistance of antibiotic-resistant cocci and attempts to create biocide-resistant strains in vitro. Strains of staphylococci (including methicillin-resistant Staph. aureus (MRSA)) and enterococci (including vancomycin-resistant enterococci (VRE)) had their susceptibility to biocides assayed using broth macro dilution methods and resistant strains were selected by serial subculture on biocide-containing media. Mutants were created with relative ease; for instance, triclosan minimal bactericidal concentrations (MBCs) increased from 0.002 to 3.12 mg l(-1). Some strains of MRSA which have intermediate resistance to glycopeptides were demonstrated to have decreased susceptibility to some biocides. Biocide resistance amongst enterococci was demonstrated although there was no clear correlation between biocide and antibiotic resistance. The exact mechanisms of resistance in these strains are still being studied but it is clear that biocide resistance is an important clinical phenomenon.     

Definition of the heterocyclic pharmacophore of bacterial methionyl tRNA synthetase inhibitors: potent antibacterially active non-quinolone analogues

Potent inhibitors of bacterial methionyl tRNA synthetase (MRS) have previously been reported. Through SAR of the quinolone moiety, the right hand side pharmacophore for MRS inhibition has now been defined as an NH-C-NH functionality in the context of a bicyclic heteroaromatic system. Potent antibacterial fused-pyrimidone and fused-imidazole analogues have been obtained and enantioselective activity demonstrated. Compound 46 demonstrated very good antibacterial activity against panels of antibiotic-resistant staphylococci and enterococci.     

Characteristics and trends in the development of an epidemic process of Sonne and Flexner dysentery among preschool children

The results of studies indicate that the morbidity rates of dysentery among children attending preschool institutions and children brought up at home converged in recent years. This phenomenon was most pronounced among children of the kindergarten age group. At the same time dysentery caused by Sh. sonnei and Sh. flexnery produced a higher morbidity rate among children attending nursery in comparison with that among children of the same age group brought up at home. Group infections in preschool institutions were caused by Sh. sonnei in 89.1% of cases and by Sh. flexneri in 10.9% of cases. Outbreaks due to the transfer of infection through everyday contacts were observed only in dysentery caused by Sh. sonnei, constituting 71.4% of the total number of dysentery outbreaks.     

Effects of Chronic Isoproterenol Treatment or Submandibular and Sublingual Ablation on Microflora of Mouse Tooth Surfaces

BALB/cA mice were examined for the effects of chronic isoproterenol treatment or submandibular-sublingual gland ablation on the natural patterns of oral bacterial colonization on tooth surfaces. Indigenous microflora on the tooth surfaces of BALB/cA mice was relatively simple. The predominant bacterial groups were Enterobacteriaceae (45.9%), enterococci (29.4%) and staphylococci (15.7%). Isoproterenol, which resulted in the induced synthesis of proline-rich proteins, caused a decrease in the total cultivable bacteria on the tooth surfaces. The proportion of Enterobacteriaceae in the isoproterenol-treated mice decreased, although the proportion of other bacterial groups increased. Salivary gland ablation, which caused the loss of mucins in saliva, showed essentially the same number of total bacteria as the control. Salivary gland ablation resulted in a decrease in the proportion of Enterobacteriaceae, while the proportion of Gram-positive rods and staphylococci increased.     

Presence of UDP-N-acetylmuramyl-hexapeptides and -heptapeptides in enterococci and staphylococci after treatment with ramoplanin, tunicamycin, or vancomycin.

Analyses of the peptidoglycan nucleotide precursor contents of enterococci and staphylococci treated with ramoplanin, tunicamycin, or vancomycin were carried out by high-pressure liquid chromatography coupled with mass spectrometry (MS). In all cases, a sharp increase in the UDP-N-actetylmuramoyl-pentapeptide or -pentadepsipeptide pool was observed. Concomitantly, new peptidoglycan nucleotide peptides of higher molecular masses with hexa- or heptapeptide moieties were identified: UDP-MurNAc-pentapeptide-Asp or pentadepsipeptide-Asp in enterococci and UDP-MurNAc-pentapeptide-Gly or -Ala and UDP-MurNAc-pentapeptide-Gly-Gly or -Ala-Gly in staphylococci. These new compounds are derivatives of normal UDP-MurNAc-pentapeptide or -pentadepsipeptide precursors with the extra amino acid(s) linked to the lysine epsilon-amino group as established by various analytical procedures (MS, MS-MS fragmentation, chemical analysis, and digestion with R39 D,D carboxypeptidase). Except for tunicamycin-treated cells, it was not possible to ascertain whether these unusual nucleotides were formed by direct addition of the amino acids to UDP-MurNAc-pentapeptide (or -pentadepsipeptide) or whether they arose by reverse reactions from lipid I intermediates to which the amino acids had been added.     

Etiologic structure of bacterial dysentery in the USSR in 1983-1985

The etiological structure of dysentery in the USSR in 1983-1985 is characterized. Sonne dysentery was found to prevail in the territories with adequate water supply, while dysentery caused by Shigella flexneri prevailed at the territories with unsatisfactory water supply. S. dysenteriae and S. boydii were found to play a limited role in the etiology of dysentery. In the presence of global pandemic, an increase in the isolation rate of S. dysenteriae I in the USSR is observed. The data on the biochemical structure of S. sonnei are presented.     

Regional heterogeneity of bacteria and their glycosidase activities across and along the colonic segments of rats

Numbers of Bacteroidaceae, Enterobacteriaceae and staphylococci were higher in the periphery of the colonic contents of rats than in the core. Numbers of total anaerobic bacteria, lactobacilli and enterococci did not differ among these regions. Activities of glycosidases were higher in the periphery than in the core.