Antibiotic sensitivity of Haemophilus influenzae isolated from patients with inflammatory lung diseases

In 1980-1986 the sensitivity of 2,045 H. influenzae strains isolated from the bronchial contents of patients with inflammatory lung diseases were studied. This study revealed that 60-80% of H. influenzae cultures circulating in Leningrad were sensitive to tetracyclin, chloramphenicol and erythromycin. During the period of observation the tendency towards the decrease of the number of highly sensitive H. influenzae cultures and the increase of the number of strains resistant to all antibiotic preparations was followed. Most of H. influenzae strains isolated in Leningrad were sensitive to penicillin, oleandomycin and ampicillin. In 1983 the appearance of H. influenzae strains, multiresistant to antibiotics, was noted. In 1986 these strains constituted 4.5% of all isolated cultures.     

Sensitivity to antibiotics of pneumococci isolated from patients with chronic nonspecific pneumonia and bronchitis

Four hundred and twenty two pneumococcal strains isolated from 300 patients with chronic nonspecific pneumonia and bronchitis were studied with respect to their sensitivity to 18 antibiotics within a period from 1982 to 1985. It was shown with the method of serial dilutions on solid media that 91.7, 87.8, 85 and 81 per cent of the isolates were sensitive to benzylpenicillin, ampicillin, lincomycin and cefuroxime, respectively. A significant percentage of the pneumococcal strains had decreased sensitivity to benzylpenicillin (MIC close to the therapeutic concentration). On this basis it was recommended to use lower concentrations of benzylpenicillin (less than 0.25 units/ml) in assay of sensitivity in clinical strains of Pneumococcus.     

Pneumococcus serotypes in acute and chronic inflammatory lung disease (1978-1980)

The comparison of the antigenic structure of the polysaccharide capsule in 342 pneumococcal strains isolated in Leningrad from the bronchial contents of patients with acute and chronic inflammatory pulmonary diseases indicated that during 1978-1980 a change in the composition of the prevailing groups of serotypes occurred every year. The comparison of the groups of prevailing pneumococcal serotypes isolated from children and adults has revealed no statistically significant differences in the specific prominence of different types, with the exception of serotype 15. Serotypes 6, 7 and 2 have been found to occur most frequently in acute pneumonia, and serotypes 23, 3, 9, 6, 15, 29 and 34 in chronic inflammatory pulmonary diseases. The preliminary data on the differences in the composition of the prevailing pneumococcal serotypes causing acute pneumonia in Leningrad and Kaunas have been obtained.     

Etiology of acute pneumonia occurring against a background of influenza and other acute respiratory viral infections

The etiology of acute pneumonia (AP) was studied in 229 patients who had the disease simultaneously with influenza (106 patients), other viral and mycoplasmal infections (48 patients), and without concomitant acute viral infections (75 patients). The use of the quantitative microbiological method and the indirect immunofluorescence test with autostrains or Streptococcus pneumoniae strains of serotypes 2, 3, and 6, prevailing in Leningrad in patients with acute inflammatory diseases of the lungs, made it possible to find out the pneumococcal etiology of AP in 95% of patients irrespective of the presence of acute respiratory viral infections. The etiological role of opportunistic bacteria was revealed in 13 AP patients (5.7%); in 2 of them the causative agent of AP was Staphylococcus aureus and in 11, various species of Gram-negative enterobacteria. The latter were the cause of complications in 8 cases of pneumococcal pneumonia.     

Streptococcus pneumoniae serotypes in children with chronic inflammatory diseases of the respiratory organs

During the 7-year period of observation (1982-1988) the serotypes of 276 pneumococcal strains isolated from children with chronic bronchopulmonary diseases were studied. Among the serotypes of pneumococci under study, serotypes 6, 19 and 15 held the leading place and included a half of all typed pneumococci. Dynamic observation on the serotype composition of pneumococci revealed periodic fluctuations in the occurrence of some types/groups. The regional analysis of different serotypes of pneumococci showed the common occurrence of serogroups 6 and 19, as well as some regional features in the circulation of serotypes 6, 10, 3 and rarely occurring serotypes. The study revealed that any new exacerbation of the chronic bronchopulmonary process is caused by pneumococci of some other serotype. Pneumococcal strains, resistant (3.4%) and sensitive (1.8%) to penicillin, were detected; most of them belonged to serogroup 19.     

Biological characteristics of Streptococcus pneumoniae strains isolated from children with pneumococcal diseases

The biological properties of 97 S. pneumoniae strains isolated from 92 children with purulent meningitides, meningoencephalitides, pneumonia and otitis, hospitalized at the Leningrad Research Institute of Childhood Infections, were studied. The data obtained in this investigation were indicative of the formation of atypical forms of pneumococci (R-forms, unbalanced growth forms and L-forms) in all clinical forms of pneumococcal infection in children. In purulent meningitides and meningoencephalitides serovars 1 and 6, in pneumonia serovars 1, 3 and 6 and in otitis serovars 6 and 19 played the leading role. The determination of sensitivity to antibiotics showed that the forms under study retained high sensitivity to a number of antibiotics. The appearance of strains resistant to benzylopenicillin was registered. (10%). The isolated strains either possessed low virulence or were avirulent in bioassay on white mice.     

Virulence of Streptococcus pneumoniae strains belonging to different serovars

The study of the virulence of 352 S. pneumoniae strains isolated from patients with inflammatory lung diseases revealed that their virulence depended, to a certain extent, on the state of the polysaccharide capsule of streptococci, as among 299 typed cultures 38.1% were virulent, while out of 53 nontypable strains of these bacteria only 8 strains (15.1%) proved to be highly pathogenic for white mice and all S. pneumoniae R-forms proved to be avirulent. All 11 S. pneumoniae strains under study belonging to serovars 1 and 2 and 87% of the cultures belonging to serovar 3, isolated from patients with inflammatory lung diseases in Leningrad, were highly virulent. The characteristic feature of S. pneumoniae cultures of other serotypes was their wide spectrum of pathogenicity. S. pneumoniae cultures isolated from the spinal fluid of patients with pneumococcal meningitis also differed in their pathogenicity levels but strains highly pathogenic for mice prevailed.     

Sensitivity of antibiotic-resistant strains of Salmonella to new antibiotics and chemotherapeutic agents]

One hundred and sixty two antibiotic resistant strains of Salmonella isolated within 1984-1988 in Leningrad and the Leningrad Region were tested with respect to their sensitivity to new antibiotics and chemotherapeutics developed or being developed in the USSR. At the background of high numbers of circulating Salmonella strains resistant to the routinely used antibiotics such as doxycycline, streptomycin and gentamicin they appeared to be highly sensitive to amikacin, ciprofloxacin, pefloxacin and the 3rd generation cephalosporins i.e. ceftazidime and cefotaxime as well as to thienamycin. These modern antibacterial agents are possibly to be the drugs of choice in etiotropic treatment and chemoprophylaxis of septic acute intestinal infections due to Salmonella strains with multiple resistance. Resistance of individual Salmonella strains to cefotaxime and ceftazidime indicated that it was possible to use their property for additional labeling of the pathogens within a serological type of Salmonella while conducting epidemiological examinations during outbreaks of acute intestinal infections of Salmonella etiology.     

Streptococcus pneumoniae in Saliva of Dutch Primary School Children

While nasopharyngeal sampling is the gold standard for the detection of Streptococcus pneumoniae carriage, historically seen, saliva sampling also seems highly sensitive for pneumococcal detection. We investigated S. pneumoniae carriage in saliva from fifty schoolchildren by conventional and molecular methods. Saliva was first culture-enriched for pneumococci, after which, DNA was extracted from all bacterial growth and tested by quantitative-PCR (qPCR) for pneumococcus-specific genes lytA and piaA. Next, serotype composition of the samples was determined by serotype-specific qPCRs, conventional-PCRs (cPCR) and sequencing of cPCR amplicons. Although only 2 (4%) of 50 samples were positive by conventional diagnostic culture, 44 (88%) were positive for pneumococci by qPCR. In total, we detected the presence of at least 81 pneumococcal strains representing 20 serotypes in samples from 44 carriers with 23 carriers (52%) positive for multiple (up to 6) serotypes. The number of serotypes detected per sample correlated with pneumococcal abundance. This study shows that saliva could be used as a tool for future pneumococcal surveillance studies. Furthermore, high rates of pneumococcal carriage and co-carriage of multiple pneumococcal strains together with a large number of serotypes in circulation suggests a ubiquitous presence of S. pneumoniae in saliva of school-aged children. Our results also suggest that factors promoting pneumococcal carriage within individual hosts may weaken competitive interactions between S. pneumoniae strains.     

Drug resistance in Shigella dysenteriae,S flexneri and S boydii in England and Wales: increasing incidence of resistance to trimethoprim.

A total of 2753 strains of shigella belonging to subgroups A, B, and C that were isolated from patients in England and Wales during the period from 1979 to mid-1983 were studied. Of these, 1690 (61%) were from patients recently returned from abroad or in contact with recent travellers, and 760 (45%) of these affected travellers from the Indian subcontinent. The number of strains resistant to sulphonamides and streptomycin remained at a high level throughout (average 76% and 72% respectively). Resistance to tetracyclines, ampicillin, and chloramphenicol rose, reaching 63%, 51%, and 48%, respectively, in 1982. Strains resistant to trimethoprim were seen in substantial numbers for the first time and increased from 1.3% of all strains in 1979 to 9.9% in 1982 and 16.8% in the first half of 1983. The proportion of patients with recent foreign contact was notably smaller among those with strains resistant to trimethoprim than among those with strains sensitive to trimethoprim. The increase in resistance to trimethoprim might partly result from the use in Britain of compounds containing trimethoprim for the treatment of shigellosis.     

Experimental and epidemiological estimation of seasonal and climato-geographical features of non-specific resistance of the organism to influenza

One and the same series of live influenza vaccine from the strains B/Dushanbe/66 and B/Leningrad/67 or A2/Moscow/21/65 administered intranasally to non-immune persons in Leningrad and 'krasnodar in winter caused an increase in body temperature in 6.7-8% of vaccinated subjects, but in summer in 0.8%. In the transitional seasons of the year (in May and in October), 6.3-16.8% of reactions were observed in Murmansk and 0.1% in Krasnodar. An increase in antibodies in the vaccinated in Leningrad and Arkhangelsk in winter was observed 1.5 times more frequently than in summer. In Krasnodar, seroconversion occurred in only 5.7% in May and october, but in 31.3% in January; in Murmansk in 41.2-48% in May and in 75.6-78.8% in October. The seasonal as well as latitudinal and climatic differences in reactogenicity and antigenic activity of the vaccine can be explained by seasonal oscillations in non-specific resistance of people of influenza viruses. The importance of this factor in the mechanism of seasonal occurrence of influenza is discussed.     

Epidemiologic problems of pneumococcal infection

During the microbiological examination of 314 tentatively healthy donors, residents of Leningrad, Streptococcus pneumoniae was detected in the rhinopharynx of 94 donors (29.9%) in amounts ranging from a few individual microbial cells to 10(6) microbial cells with the mean geometric concentration equal to 3.58 lg. Antipneumococcal antibodies were detected in the blood of 147 donors (46.8%). The occurrence of antipneumococcal antibodies was approximately 2.5 times higher than the average level of carriership, but in most cases the dynamics of immunological reactions changed in the same direction. Considerable monthly and annual fluctuations in the occurrence of pneumococcal carriership and antipneumococcal antibodies, as well as their correlation with the epidemic rises of acute respiratory diseases, influenza and other acute respiratory viral diseases, were established. These data indicate that pneumococcal infection plays a definite role in the epidemic rises of acute respiratory diseases.     

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.     

Effect of vaccination against pneumococcal infection and influenza in children with asthma

Assessment of clinical course of asthma and IgG response in children with asthma immunized with pneumococcal polysaccharide vaccine (Pneumo 23) and influenza vaccine (Vaxigrip). 78 children aged 4 - 17 years old were allocated to two groups. Children from the 1st group were immunized against pneumococcal infection and influenza; children from 2nd group were immunized against pneumococcal infection only. Rate of asthma exacerbations in the 1st group of children decreased by 1.7 times compared with the period before vaccination, whereas the same rate in the 2nd group of children decreased by 1.5 times. It was accompanied by the increase of IgG level to antigens of pneumococcalvaccine in blood, which was observed in both groups. Vaccination did not result in increase of IgE levels. Immunization of children with asthma against pneumococcal infection with polysaccharide vaccine or combined immunization against pneumococcal infection and influenza reduced rate of asthma exacerbations and led to formation of immunity to vaccine strains of Streptococcus pneumoniae. Vaccination did not lead to sensitization of children.     

Characterization of Protective Immune Responses Induced by Pneumococcal Surface Protein A in Fusion with Pneumolysin Derivatives

Pneumococcal surface protein A (PspA) and Pneumolysin derivatives (Pds) are important vaccine candidates, which can confer protection in different models of pneumococcal infection. Furthermore, the combination of these two proteins was able to increase protection against pneumococcal sepsis in mice. The present study investigated the potential of hybrid proteins generated by genetic fusion of PspA fragments to Pds to increase cross-protection against fatal pneumococcal infection. Pneumolisoids were fused to the N-terminus of clade 1 or clade 2 pspA gene fragments. Mouse immunization with the fusion proteins induced high levels of antibodies against PspA and Pds, able to bind to intact pneumococci expressing a homologous PspA with the same intensity as antibodies to rPspA alone or the co-administered proteins. However, when antibody binding to pneumococci with heterologous PspAs was examined, antisera to the PspA-Pds fusion molecules showed stronger antibody binding and C3 deposition than antisera to co-administered proteins. In agreement with these results, antisera against the hybrid proteins were more effective in promoting the phagocytosis of bacteria bearing heterologous PspAs in vitro, leading to a significant reduction in the number of bacteria when compared to co-administered proteins. The respective antisera were also capable of neutralizing the lytic activity of Pneumolysin on sheep red blood cells. Finally, mice immunized with fusion proteins were protected against fatal challenge with pneumococcal strains expressing heterologous PspAs. Taken together, the results suggest that PspA-Pd fusion proteins comprise a promising vaccine strategy, able to increase the immune response mediated by cross-reactive antibodies and complement deposition to heterologous strains, and to confer protection against fatal challenge.     

Phenotypic and genotypic discrepancy of Streptococcus pneumoniae strains isolated from Asian countries

Non-typeable isolates of Streptococcus pneumoniae collected from Asian countries were characterized by optochin susceptibility test, bile solubility test, multilocus sequence typing of housekeeping genes, amplification of virulence-related genes, 16S rDNA-RsaI digestion, and 16S rDNA sequencing. Six of 54 non-typeable pneumococcal isolates showed divergence of gene sequences of recP and xpt from typical pneumococcal strains. Of these six atypical pneumococcal strains, two showed different results in optochin susceptibility or bile solubility test from typical pneumococcal strains. All six isolates showed high sequence dissimilarities of multilocus sequence typing, 16S rDNA sequences, and lytA sequences from typical S. pneumoniae strains. Data from this study suggest that classic tests such as optochin susceptibility and bile solubility tests may lead to incorrect identification of S. pneumoniae. These atypical strains may belong to different bacterial species from S. pneumoniae.     

Amikacin in the treatment of infectious-inflammatory diseases in patients at a therapeutic hospital

Amikacin sensitivity of 157 strains which caused infectious inflammatory diseases in patients of a therapeutic hospital was studied. It was shown that 52 and 42.9% of the isolates from patients with bronchopulmonary infections were highly and moderately sensitive to amikacin, respectively. 5 pneumococcal strains were resistant to amikacin. Among the isolates from urine of the patients with urinary infections there were no strains resistant to amikacin. Study of amikacin pharmacokinetics demonstrated expediency of antibiotic endobronchial administration to patients with bronchopulmonary diseases and aggravation of chronic purulent inflammatory processes. A favourable clinical effect of amikacin after its intramuscular or endobronchial administration was observed in 53.3% of the patients. In 30% of the patients the effect was satisfactory. In 16.7% of the patients the treatment failed. Satisfactory antibiotic tolerance in the majority of the patients was stated.     

Correlations between cadmium treatment, oxygen uptake and metallothionein response in liver and kidney from two mice strains

Oxygen uptake was determined in liver and kidney slices from Balb/C and C3H/HeJ mice at various time points related to a 4-day cadmium (Cd) i.p. injection regime, the latter strain being not only the higher metallothionein (MT) responder, but also more Cd sensitive. In both strains Cd injections caused an increase in O2 uptake in the tissues, being more expressed in the higher MT responsive C3H/HeJ strain. An ability for fast, additional increase of O2 uptake in response to subsequent Cd exposure was also induced during the injection regime. Maximal obtainable MT levels in the two strains were estimated by forced overwhelming pneumococcal infection challenge, giving induction values above those obtained for the Cd injections in the Balb/C strain and equal to those obtained for Cd in the more responsive C3H/HeJ strain. Together with direct defendants against harmful oxygen radicals, MT may act complementary as a radical scavenger and by Cd inactivation, but to a higher degree in the C3H/HeJ compared to the Balb/C strain.     

The Role of Plant Hormones and Benzoic Acid in Flowering of Lemna paucicostata 151 and 381

The effects of plant hormones on flowering of Lemna paucicostata151 and 381 were investigated when exogenously applied in combinationwith benzoic acid. These strains are very sensitive to benzoicacid and flower readily on application of benzoic acid. Theflower-inducing effect of benzoic acid was strongly modifiedby plant hormones: gibberellins, indole-3-acetic acid and abscisicacid were inhibitory, while cytokinins were promotive (synergistic),suggesting that the balance between endogenous levels of benzoicacid and plant hormones contributes to the regulation of floweringin Lemna. (Received October 6, 1982; Accepted December 23, 1982)     

An easy method for detection of nasopharyngeal carriage of multiple Streptococcus pneumoniae serotypes

In this paper, a simplified method for detection of pneumococcal carriage and for revealing the presence of several serotypes in a nasopharyngeal sample is evaluated. Enrichment broth was used for transportation and for the initial culturing of samples. All specimens were examined directly by the capsular reaction test for the presence of any of the 91 known pneumococcal serotypes. Sub-culturing on blood agar was used for isolation of the pneumococcal strains detected in the primary broth culture. A total of 693 nasopharyngeal swabs were obtained among children, their parents and employees in day care centres. Pneumococci were observed in 363 samples and 36 of these (9.9%) contained more than one serotype (multiple carriages). Two persons carried 3 different serotypes simultaneously. A significant increase in the positive sampling rate (5.8%) was achieved by using the simplified method compared to conventional streaking of the swabs directly on blood agar (p<0.0001).