The epidemiological aspects of campylobacteriosis in children in arid area]

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.     

Hemagglutinating and adhesive capacities of Klebsiella and Enterobacter strains

The authors analyze the data of studies on the hemagglutinating and adhesive capacity of 290 cultures, including 118 K. pneumoniae strains and 64 E. cloacae strains isolated from sick children, as well as 59 K. pneumoniae strains and 49 E. cloacae strains isolated from healthy children. The hemagglutinating properties of the strains were determined in the hemagglutination test with fresh, formalin- and tannin-treated red blood cells, the adhesive properties were studied by light microscopy. Among K. pneumoniae and E. cloacae strains isolated in acute intestinal infections, mannose-sensitive hemagglutination and pronounced adhesive activity were prevalent in most cases. Poorly adhesive and nonadhesive strains were characteristic of K. pneumoniae and E. cloacae cultures isolated from healthy children. The strains isolated from sick and healthy children differed only by the prevalence of adhesive cultures.     

The prevalence of Yersinia and its serologic variants in patients with acute intestinal diseases of undetermined etiology in Leningrad

Among Yersinia enterocolitica strains of 32 serovars, proposed as typing strains, some strains were found to belong to new species. Y. enterocolitica sensu stricto was represented by 21 serovars in the collection of typing strains. The occurrence of different Yersinia serovars in patients with acute enteric diseases of unknown etiology in Leningrad in 1983-1986 was determined with the use of the set of monoreceptor to 21 serovars. Out of 2,947 cultures studied by biochemical and serological methods, 81% were typed. Among them 18 Y. enterocolitica serovars were determined. Their characteristic feature was the prevalence of serovar O3 and an insignificant proportion of serovar O9. More frequently Yersinia were detected in patients with the primary diagnosis of acute enteric diseases (93.5%). The overwhelming majority (two-thirds) of Yersinia strains were isolated from children. A great number of strains detected in this study (70%) was isolated on days 10-15 of the bacteriological examination. In 927 cultures the following biovars were determined: the strains of serovar O3 belonged to biovar 4 and all other strains, to biovar 1.     

Pneumococcal serotypes in various diseases of children

The serotyping of pneumococci isolated from different material obtained from children aged 0 to 11 years was carried out. Out of 156 patients with different diseases, hospitalized in two clinics in Moscow during February-May 1983, pneumococci were isolated from 67 patients (43%). The isolated pneumococcal strains belonged to 11 serotypes. Pneumococci of serotypes 3, 6, 9 and 19 were shown to occur most frequently in different diseases and constituted 50% of the isolated strains. The inoculation of the material by the quantitative method permitted the authors to find out the role of pneumococci as the etiological factor in the pathogenesis of some diseases. A certain dependence of diversity in the types of isolated pneumococci on the age of sick children was noted. Almost all isolated strains were found to be sensitive to penicillin, ampicillin and benzylpenicillin. But a few individual strains were sensitive only to one of these antibiotics. The data on some biological properties of pneumococci cultivated on solid culture media are presented.     

Comparative characteristics of the Haemophilus influenzae strains isolated from healthy children and from patients with acute and chronic bronchopulmonary diseases

The comparative biochemical and serological characterization of 424 H. influenzae strains isolated from healthy children and patients with acute and chronic bronchopulmonary diseases is presented. As the result of biotyping H. influenzae strains, 82.3-90.9% of the strains isolated from both healthy children and patients with acute and chronic bronchopulmonary diseases were found to belong to the first three biotypes according to M. Kilian's classification. Among H. influenzae strains isolated from healthy children no capsular variants were detected in the coagglutination test. From patients with acute and chronic diseases of respiratory organs, as a rule, the capsular variants of H. influenzae were isolated (94.4% and 98.1%, respectively). In patients with chronic pneumonia biotypes I, II and III, more seldom biotype V, proved to be mo st invasive. In the determination of the minimum inhibiting concentration of ampicillin, no H. influenzae strains resistant to this antibiotic were detected.     

Antigenic anachronism of the influenza A(H2N2) viruses in Leningrad in 1980. I. The epidemiological and serological characteristics of the influenzal infection caused by A/Leningrad/80 (H2N2) viruses

In April-May 1980 a number of unrelated outbreaks of influenza-like diseases were registered in Leningrad in an infant home (50 out of 68 children under observation, aged 3 months to 2 years, were affected) and among the pupils of a boarding school (13 out of 50 adolescents under observation, aged 15-17 years, were affected). 5 strains of influenza A virus were isolated from 3 sick children and 1 clinically healthy child. A similar virus was isolated from a sick adolescent in a boarding school, as well as from a female patient aged 24 years at a domiciliary focus of infection (a sporadic case). In the subsequent laboratory investigation all these 7 strains were identified as viruses A/H2N2. Isolated cases of seroconversion to hemagglutinin H2 were definitely registered in 6 patients during February--May 1980. In 3 cases, including the 24-year old female patient with an acute respiratory disease, seroconversion to hemagglutinin H2 was observed in combination with the release of influenza viruses A/H2N2 from these patients. 2 influenza virus strains with this antigenic characteristic were isolated from a young female patient at an interval of 3 days. Among the patients admitted to the clinics of the Research Institute of Influenza in Leningrad on account of acute respiratory diseases isolated cases of diagnostically significant seroconversion to hemagglutinin H2 constituted 3.5% among children and 4.5% among adults. The study of the level of antihemagglutinins in the population revealed that in 1980 persons aged 18-50 years showed a high level of antihemagglutinins.(ABSTRACT TRUNCATED AT 250 WORDS)     

Resistance to antibacterial drugs of Enterobacteriaceae isolated from healthy children and from those with Salmonella infections

A total of 2329 Enterobacteriaceae strains in bacterial associations isolated from healthy children and children with salmonellosis were tested for their resistance to antimicrobial drugs. It was shown that the aerobic microbial associations isolated from the healthy children contained higher numbers of strains sensitive or resistant to 1-3 antibiotics while the microbial associations from the children patients with salmonellosis treated with antibiotics contained higher numbers of strains resistant to 6-8 antibiotics. Resistance of the aerobic bacterial associations was mainly defined by resistance of E. coli and K. pneumoniae. The feces of the healthy children never treated with antimicrobial drugs contained strains resistant to them. The use of the antibiotics in the treatment led to increasing numbers of the resistant bacteria and changing species composition of the bacterial associations.     

Pneumococcal serotypes in children with acute and chronic inflammatory diseases of the lungs and in healthy children

The serotyping of 350 Streptococcus pneumoniae strains isolated from patients with acute and chronic diseases of the respiratory organs and from healthy children was carried out with the use of the agglutination test. 145 pleural fluid samples were tested for the presence of the pneumococcal antigen and its K-type. The prevailing pneumococcal serotypes were 6, 1, 19, 12 and 9 in acute pneumonia and 6, 19, 42, 3 and 12 in chronic pneumonia, including, respectively, 64.8% and 62% of all typed strains. Cases of pneumonia with complications in the form of pleuritis were mostly induced by serotypes 3, 1, 12 and 14, while in the destructive forms of pneumonia K-types 3, 14, 9 and 12 were isolated. Examinations of healthy pre-school children have shown 16.1% of them to be transitory pneumococcus carriers. Multiple biological examinations carried out during 1.5 years revealed that in this period 42.4% of the children were pneumococcus carriers.     

Study of the properties of E. coli of serological group 03 isolated in acute intestinal diseases]

The authors studied the properties of 115 strains of E. coli of serological group 03 isolated from 49 children and adults with acute intestinal disturbances. The majority of the children (82.9%) were aged under one year. Results of the study of the antigenic structure and biochemical properties permitted to differentiate the strains isolated into 3 serological types, with the prevalence of strains of type O3 : K2 (L) : H2 (78.3%), and 8 biochemical variants. The majority of the strains possessed hemolytic properties. Strains of serological group O3 were isolated repeatedly from the patients during the sickness, whereas none were revealed in examination of 132 healthy children and adults. The data obtained permitted to consider these microbes to be possible causative agents of intestinal coliinfection, and to refer them to the enteropathogenic category.     

Bacteriocinogenic highly antagonistic strains of lactobacilli

Ability to secrete bacteriocines and microcines was studied in 25 cultures of lactobacilli isolated from intestine of healthy children. Sixteen (64%) of them produced microcines with wide spectrum of antagonistic activity. Susceptibility of microcines-secreting cultures to antibacterial preparations, different dilutions of hydrochloric acid and bile was studied along with their acid-producing ability. Five strains without DNA-se, RNA-se, gelatinase, lecitinase and caseinolytic activity were selected from Sixteen microcines-producing cultures. Three of the selected strains carried plasmid DNA and two didn't have plasmids. Bacteria were characterized by tolerance to hydrochloric acid and bile - minimal inhibitory concentrations for them were 1,25 and 10% respectively. Strains without plasmids were susceptible to majority of wide-spectrum antibiotics and resistant to fluorochinolones. Microcines-producing lactobacilli with wide spectrum of antagonistic activity against pathogenic and conditionally pathogenic microorganisms and tolerance to physiological concentrations of hydrochloric acid and bile have a potential to be used in manufacturing of probiotics.     

Streptococcus pneumoniae serotypes in children with acute pneumonia and pleurisy

The study of pneumococci of different serotypes, isolated from patients with acute pneumonia and pleuritis and from healthy children was carried out. Among the pneumococcal serotypes causing pneumonia and pleuritis in children serotypes 1, 6, 19, 14 and 3 were most widely spread and constituted 62.3% of all isolated pneumococci. In young children cases of acute pneumonia and pleuritis were more often induced by serotypes 6 and 14 and in older children, by serotypes 1 and 3. In patients with uncomplicated pneumonia and pleuritis differences in the detected serotypes of pneumococci were observed, and the disease course differed in severity. Serotypes 14, 3 and 3 induced destructive processes in the lungs more often than other serotypes. Monitoring of the sensitivity of pneumococci to antibiotics showed that most of the strains retained high sensitivity to penicillin and ampicillin. In most cases the detected resistant pneumococcal strains belonged to serogroup 19.     

Antibiotic sensitivity of the microflora isolated in ENT diseases]

Sensitivity of beta-hemolytic streptococci of group A, Streptococcus viridans, Staphylococcus aureus, epidermal staphylococci, pneumococci, Proteus and Ps. aeruginosa isolated in 1975-1978 from patients with tonsillitis, otitis, sinusitis and other otorhinolaryngological diseases was studied with respect to 19 antibiotics. Data on comparison of the antibiotic sensitivity of the microflora isolated from the patients with otorhinolaryngological diseases in 1964-1974 and 1975-1978 are presented. It was shown that beta-hemolytic streptococci were highly sensitive to all the antibiotics tested except tetracycline. Among Streptococcus viridans the strains resistant to many antibiotics were more frequent than among beta-hemolytic streptococci. Most of the Staphylococcus aureus strains were sensitive to gentamycin, cephaloridin, oxacillin and resistant to the other antibiotics. The epidermal staphylococci were characterized by approximately the same antibiotic sensitivity as Staphylococcus aureus. Resistance of the predominating majority of the Pneumococcus strains to tetracycline was noted. Proteus and Ps. aeruginosa were resistant to all the antibiotics except aminoglycosides. The microflora isolated from the cases with otorhinolaryngological diseases in 1975-1978 were mainly characterized by lower antibiotic sensitivity than that isolated from the cases with the same diseases in 1964-1974. It is possible to suppose that the microorganisms isolated from the patients with otorhinolaringological diseases had no significant differences with respect to their antibiotic sensitivity from those isolated from the patients with other pathological processes.     

Enterotoxigenic Escherichia in patients with acute intestinal infection

Out of 4,082 Escherichia strains isolated from 989 hospitalized patients with acute enteric infections 2,979 strains belonged to 139 O-groups and the remaining strains could not by typed with O-sera (O1-O164) or were in the serological R-form. 19.3% of the strains isolated from 354 patients showed a positive reaction for thermolabile enterotoxin (TLET) determined in the radioimmunoassay. Escherichia with pronounced reaction for TLET were isolated from 5.5% of the patients. The serological picture of Escherichia with a positive reaction for TLET comprised 78 O-groups, showed practically no variations in children of different age and adult patients and was related to the intensity of reaction for TLET. The number of enterotoxigenic Escherichia greatly varied within individual O-groups: from 3.1 +/- 3.63% (O11) to 100 +/- 9.81% (O114) of the total number of known strains in these O-groups. In most O-groups the number of enterotoxigenic strains varied from 10% to 50%. The most widely spread serovars of etiologically important enterotoxigenic Escherichia belonged to 24 O-groups and were often isolated as monocultures. The capacity for producing TLET (and, probably, some other antigenically related substances) in widely spread among Escherichia; still, the determination of enterotoxicity is a necessary, but not sufficient criterion of their etiological importance in acute enteric infections.     

Biological properties of enterotoxigenic Escherichia isolated from patients with acute intestinal diseases of unknown etiology

As the result of the comparative examination of adult patients with acute enteric diseases and normal adults, 173 E. coli enterotoxigenic strains were isolated (161 strains from the patients and 12 strains from normal persons). 83% of the isolated enterotoxigenic E. coli (ETEC) produced two enterotoxins: thermolabile (LT) and thermostable (ST). Enterotoxigenicity was most pronounced in the strains of ETEC belonging to the prevaling variant ST + LT +. The enterotoxigenic properties of ETEC were highly stable: the production of ST and LT in the strains remained unchanged after their storage for up to 4 years. The isolated ETEC comprised 48 serogroups and 61 strains. The strains belonging to the same seroval had a similar degree of toxigenicity. The strains belonging to different serovars considerably differed in the activity of their enterotoxins. The production of two kinds of enterotoxins in the isolated E. coli strains was inter-related: the strains with a high activity of ST were, as a rule, good producers of LT.     

Data on the study of the epidemiology of rotavirus infection in Leningrad

The results obtained in the study of rotavirus infection in Leningrad in 1984-1987 are presented. Enzyme immunoassay techniques were used for the examination of 4,715 children aged 0-14 years and 1,162 adults with diagnosed acute enteral infection of unknown etiology, as well as the control group of 556 of healthy children aged 0-6 years and 77 healthy adults. The rotavirus antigen was detected in 1.210 sick children (25.7%) and 133 sick adults (11.4%), as well as in 6 healthy children (1.1%), but not detected in healthy adults. The following epidemiological regularities of rotavirus infection were established: the highest sick rate among children aged 0-2 years and a low level of rotavirus carriership among healthy persons; the seasonal character of rotavirus infection, its outbreaks occurring in winter and the epidemic periods varying in their character and duration in different years; the prevailing role of rotaviruses in the development of winter rises of acute enteral infection of unknown etiology in the city among children aged 0-2 years. The problem of the respiratory syndrome in rotavirus diarrhea is discussed. The rotavirus antigen was detected in 39 out of 144 children (27%) with diagnosed acute respiratory virus diseases and in 4 out of 99 nasopharyngeal washings (4%) from diarrhea patients. Adenoviruses were shown to play an insignificant role in the etiology of diarrhea (10% of cases).     

The hydrophobicity of gram-negative bacteria isolated from patients with inflammatory and suppurative-destructive lung diseases]

Hydrophobic properties of 11 enterobacterial strains and 12 Pseudomonas aeruginosa strains isolated from patient with inflammatory and purulent destructive diseases of the lungs were studied. The hydrophobic properties of the isolated bacteria were determined by the method of salting out with ammonium sulfate. A high correlation (r = 0.56) between the above-mentioned properties of gram-negative bacteria and their isolation rate from patients with destructive diseases was established. The hydrophobic properties of bacteria were supposed to be of importance in the process of the colonization of pulmonary tissues with bacterial flora.     

occurrence of mannose- resistant adhesins MRHA in E.Coli strains isolated from children with diarrhea]

The study was aimed at determination of the frequency of occurrence of mannose-resistant adhesins in E. coli strains isolated from children with diarrhoea. It was also of interest whether their presence is associated with the serological type or other virulence factors. The material used in this study consisted of 1022 strains of E. coli (EPEC, ETEC and EIEC) and 3431 isolates from sick children and 960 from healthy children (non-EPEC-ETEC-EIEC). Enterotoxigenicity and entero-invasiveness of strains was evaluated by biological tests performed on animals and in tissue culture. Production of MRHA adhesins was determined by the test of mannose-resistant active hemagglutination, and of colonization factors antigens CFA by application of agglutination and agar gel immunodiffusion tests. Most frequently MRHA adhesins were produced by ETEC strains-80% of strains. All of them appeared to be a colonization factor antigen CFA/I. EPEC strains produced various MRHA adhesins only by 12.6% of strains. Production of MRHA adhesins by EIEC strains was not detected. Frequency of occurrence of MRHA adhesins in E. coli strains which were non-EPEC-ETEC-EIEC was dependent from the isolation source. MRHA adhesins were most frequently found in strains isolated from sporadic cases of light diarrhoea in ambulatory treated children (49%), much less among isolates from children hospitalized because of severe diarrhoea (33%), and from healthy children in 9% of isolates only. These results may indicate the potential role of MRHA adhesins in pathogenesis of diarrhoea in children.     

Antilactoferrin activity of microorganisms

The detection rate of the antilactoferrin sign and the level of its manifestation in 165 strains of different microbial species, isolated from patients with inflammatory diseases and intestinal dysbacteriosis, were analyzed. The detection rate of antilactoferrin activity was 43 - 90% for Escherichia coli strains, 20 - 86% for Staphylococcus aureus, 60 - 100% for Klebsiella pneumoniae, 76 - 78% for Candida albicans, isolated from different biotopes of man. Most frequently and with high levels of manifestation this sign was registered in strains isolated from the reproductive tract of women. The detection rate of this sign and the level of its manifestation in bacteria of the vaginal and cervical microbiocenosis, isolated from patients, were higher in comparison with healthy persons. The inverse dependence between the level of the antilactoferrin activity of microflora and the content of lactoferrin during the inflammatory process in women was established.     

Periodontal disease as reservoir for multi-resistant and hydrolytic enterobacterial species

AIMS: This investigation aimed to isolate enteric rods from subgingival sites of patients presenting chronic periodontitis lesions, and to assess antimicrobial resistance and expression of hydrolytic enzymes. METHODS AND RESULTS: Enterobacteriaceae were isolated from 20% patients, and assayed for antimicrobial susceptibility and hydrolytic enzymes with specificity to different substrates. Isolates comprised seven Enterobacter cloacae (43.75%), five Serratia marcescens (31.25%), one Klebsiella pneumoniae (6.25%), one Enterobacter aerogenes (6.25%), one Pantoea agglomerans (6.25%), and one Citrobacter freundii (6.25%). Gelatinase activity was observed for 75% strains; caseinase and elastase was produced by six and two strains, respectively. DNase, lecithinase and lipase were expressed by S. marcescens. Most of strains were resistant to ampicillin (93.75%) and amoxicillin/clavulanic acid (81.25%). The majority of strains were susceptible to cephalosporins and aztreonam. Enterobacteria remained susceptible to imipenem, streptomycin and fluoroquinolones. Resistance to gentamicin, amikacin, sulfamethoxazole/thrimethoprim, tetracycline, and chloramphenicol were also observed. Eight strains presented multiple drug resistance. CONCLUSIONS: Subgingival sites from periodontal diseases contain multi-resistant and hydrolytic enzyme-producing enterobacteria that may contribute to overall tissue destruction and spreading. SIGNIFICANCE AND IMPACT OF THE STUDY: Enterobacteria isolated from patients generally considered as healthy individuals poses periodontal diseases as reservoir for systemic infections particularly in immunocompromised and hospitalized hosts.     

Properties of E. coli of serological group 06:K13(L) isolated in acute intestinal diseases]

A study of 88 E. coli strains belonging to serological group 06: K13 (L) isolated from 50 children and 5 adults suffering from acute intestinal disturbances permitted to refer them to the serological types 06: K13 (L):H1 (82 strains) and 06: K13 (L): H--(6 strains), and to 5 biochemical types. Repeated isolation of E. coli belonging to serlogical group 06: K13 (L) in patients with acute intestinal diseases, and their absence in healthy children and adults indicated these microbes to be a possible etiological factor of the disease and to refer to the group group of enteropathogenic ones. Wide introduction of agglutinating sera 06: K13(L) into the work of practical laboratories is of expedience in connection with this.