Ivanova EI, Rvchkov LV, Nemchenko UM
… +3 more, Bukharova EY, Savelkaeva MV, Dzhioev YP
Mol Gen Mikrobiol Virusol
· 2017 · PMID 30561943
E. coli is an intestinal commensal of vertebrates. The ability to produce Shiga toxins (Stx) is the major virulence feature of Shiga toxin-producing E. coli (STEC). These potent cytotoxins block the protein synthesis by...E. coli is an intestinal commensal of vertebrates. The ability to produce Shiga toxins (Stx) is the major virulence feature of Shiga toxin-producing E. coli (STEC). These potent cytotoxins block the protein synthesis by inactivating ribosomes. Their action on the target cells is responsible for the most severe forms of STEC-induced disease, such as hemorrhagic colitis and the life-threatening hemolytic uremic syndrome (HUS). Enteropathogenic E. coli (EPEC) also continues to be an important cause of infantile diarrhea in developing countries. Bundle-forming pili (bfp) are essential for the full virulence of enteropathogenic E. coli (EPEC). Exchange of genetic material between different types of bacteria, as well as with other members of the family Enterobacteriaceae in the intestinal ecosystem, leads to the appearance of normal variants of E. coli with phenetic features of pathogenicity that can serve as a theoretical basis for attributing these strains to pathobionts. PCR was used to examine 68 strains of E. coli (E. coli with normal enzymatic activity) for the presence of genes encoding the synthesis of Shiga toxins (stxl and stx2) and genes encoding the bundle-forming pilus (bfp). They were isolated from children with functional disorders of the gastrointestinal tract. The presence of the desired amplicon specific for stxl and bfp genes has resulted in formation of E. coli strains with more intense pathogenicity.
In several regions of Russia, broad distribution of RNA-containing bee viruses was found at apiaries of honey bee Apis mellifera using RT-PCR. Detected RNA-containing bee viruses are transferred simultaneously with invas...In several regions of Russia, broad distribution of RNA-containing bee viruses was found at apiaries of honey bee Apis mellifera using RT-PCR. Detected RNA-containing bee viruses are transferred simultaneously with invasion of mite Varroa destructor and lead to mass bee mortality that results in economic losses in bee breeding. In samples of Varroa destructor, bee viruses DWV and ABPV were found. High degree of RNA-containing virus (BQCV, DWV SBV, ABPV, CBPV and KBV) infection was revealed: in the average, at least 50% for bee families with mite infection. In the bee families studied in this work, mixed infection with 2-6 viruses simultaneously was detected. Amplified fragments of viruses BQCV, DWV and SBV obtained using RT-PCR were sequenced and registered in Genbank.
The 111 strains of T. pallidum subsp. pallidum collected in Tuva Republic in 2013-2016 were typed by the arp, tpr (E, G, J) and tp0548 genes. The 7 subtypes were identified, in which the 14 d/f type was predominant (90.1...The 111 strains of T. pallidum subsp. pallidum collected in Tuva Republic in 2013-2016 were typed by the arp, tpr (E, G, J) and tp0548 genes. The 7 subtypes were identified, in which the 14 d/f type was predominant (90.1%). The minor subtypes 14 b/f, 14 c/f, 14 d/g and 14 i/f constituted 0.9-1.8%. Single strains of 4 d/f H 9 d/f types (each 0.9%) previously described in China were detected in 2015. Both 9 and 14 arp gene variants were found in 3 clinical specimens for the first time in 2015-2016. Similarities in the molecular epidemiology of syphilis in Tuva Republic and Russia were demonstrated as well as differences from the T. pallidum subsp. pallidum population in China and Western Europe.
Mobile genetic elements (in particular, retrotransposons) constitute a considerable part of eukaryotic genomes. These elements are one of the main sources of variability and instability. Although mobile genetic elements...Mobile genetic elements (in particular, retrotransposons) constitute a considerable part of eukaryotic genomes. These elements are one of the main sources of variability and instability. Although mobile genetic elements had been discovered more than 60 years ago, certain classes of these elements, such as Penelope-like elements (PLE) remain insufficiently understood. In this work, the results of in silico research into PLE of the S. japonicum genome (one of the most important human parasites from the epidemiological viewpoint) are presented. A new estimate of PLE in the S. japonicum genome was made. It was shown that their high heterogeneity presumably reflects several transposition events. Two groups of canonical PLE copies differing by the amino sequence in the domains RT and EN were found to be present in the Schistosoma genome. The data on the representation, structural features, and possible functional load and evolution of Penelope-like retroelements of the parasite are discussed.
The review contains some brief information on cholera epidemics in Africa. Based on the results of the whole genome sequencing of 30 clinical strains isolated in Africa in different periods of the 7th cholera pandemic (1...The review contains some brief information on cholera epidemics in Africa. Based on the results of the whole genome sequencing of 30 clinical strains isolated in Africa in different periods of the 7th cholera pandemic (1985-2012), extensive genetic diversity has been revealed. It is demonstrated that at present cholera epidemics in Africa are caused by new variants of the agent, which emerged in South- Eastern Asia in consequence of not only new genes acquisition, but also genome alterations of pandemicity and pathogenicity islands. SNP analysis of 53 strains circulating at different times in the territory of the continent, as well as isolated in South-Eastern Asia, has been carried out. Phylogenetic relations between the majority of the African and Asian strains have been established. In addition, strains were shown to exist that are, apparently, endemic to the African region. Identified genetic diversity of the strains with varying virulence and drug resistance points out the necessity of continuous molecular monitoring of the cholera agent in Africa.
Shigelloses still provide one of the toughest health challenges in many countries, especially in developing ones. Current molecular-genetic techniques are increasingly replacing conventional phenotypic approaches to inve...Shigelloses still provide one of the toughest health challenges in many countries, especially in developing ones. Current molecular-genetic techniques are increasingly replacing conventional phenotypic approaches to investigating Shigella-associated infections. The review describes available methods of typing Shigella bacteria, their potential applications and selection criteria depending on the research task. It also deals with their advantages and disadvantages. Such methods as PFGE (pulsed field gel electrophoresis), the "gold standard" in typing various pathogens, and MLVA (multi-locus variable number of tandem repeat analysis) are the most widely used Shigella typing procedures. These methods are often combined or used along with some other genotyping tools. In the nearest future, with the advent of web platforms allowing express processing data, whole genome sequence will possibly become more widely used in lab diagnostics to evaluate outbreaks and to perform epidemiological monitoring.
In Bacillus anthracis, an alternative to the use of chelating agents (siderophores) for acquiring iron consists in using a system of hemophores and transporter proteins for scavenging hemes from hemoglobin and delivering...In Bacillus anthracis, an alternative to the use of chelating agents (siderophores) for acquiring iron consists in using a system of hemophores and transporter proteins for scavenging hemes from hemoglobin and delivering them into the bacterial cell. B. anthracis utilizes the siderophore-mediated way of acquiring iron predominantly at the intracellular stage of its development; the system of hemoinantly at the transporter proteins is used at the extracellular stage of anthrax infection. The structure, genetic organization and functions of the system for the heme iron acquisition in B. anthracis, understanding of which may facilitate development of new therapies for anthrax, are discussed.
Kulichenko AN, Volynkina AS, Kotenev ES
… +10 more, Pisarenko SV, Shaposhnikova LI, Lisitskaya YV, Vasilenko NF, Tsygankova OI, Evchenko YM, Tohov YM, Savel'ev VN, Tihonov SN, Penkovskaya NA
Mol Gen Mikrobiol Virusol
· 2016 Sep · PMID 30380211
This work represents the results of the genetic identification of the Crimean-Congo hemorrhagic fever virus (CCHF virus) strains isolated in the Crimean Federal District in conducting the epidemiological survey of the im...This work represents the results of the genetic identification of the Crimean-Congo hemorrhagic fever virus (CCHF virus) strains isolated in the Crimean Federal District in conducting the epidemiological survey of the imported case of CCHF from Crimea in 2015. One sample of the serum from a patient and 61 pools (506 specimens) of ticks collected during the epizootiological survey of 6 administrative districts of the Crimean Federal District were tested using PCR for the presence of the CCHF virus RNA. RNA of the CCHF virus was detected in serum from a patient and 10 samples of ticks. The genetic identification of the CCHF virus was performed by sequencing the virus genome S-, M-, and L-segments. The result of the molecular-genetic analysis revealed a high degree of identity between the samples of the CCHF virus in human serum and three samples of ticks and their belonging to a new genetic Crimea subclade (Vd) of the genotype Europe 1. Whole genome sequencing of two samples of CCHF virus belonging to the Crimea subgroup (Vd) was performed. CCHF virus variants of the Crimea subclade (Vd) of the Europe- lgenotype were described for the first time. These variants were endemic to the territory of the Crimean peninsula.
Mol Gen Mikrobiol Virusol
· 2016 Sep · PMID 30380210
Epstein-Barr virus (EBV) - the etiological agent of a number of human benign and malignant tumors including infectious mononucleosis (IM), Burkitt lymphoma (BL), Hodgkin (HL) and non-Hodgkin (NLH) lymphomas, nasopharynge...Epstein-Barr virus (EBV) - the etiological agent of a number of human benign and malignant tumors including infectious mononucleosis (IM), Burkitt lymphoma (BL), Hodgkin (HL) and non-Hodgkin (NLH) lymphomas, nasopharyngeal carcinoma (NPC), and many other tumors. Latent membrane protein 1 (LMPl) encoded by the gene of the same name (LMP I) is the main oncoprotein of EBV. LMP1 is a transmembrane protein capable of activating many signaling pathways and transcription factors of the cells, which leads to its transformation. Molecular analysis of LMP1 of various clinical origins identified many variants with different types of amino acid mutations that influence its biological activity. Since the role of LMPl in the development of NPC is still not fully understood, it is important to find out how LMPl samples from patients with EBV-associated form of NPC differ from those of patients with other tumors also located in the oral cavity (OTOC), but not associated with this virus. Unlike most investigations conducted in endemic regions, the present work is intended to compare the genetic structure and the transforming activity of LMPl variants from NPC and OTOC patients has been carried out in a non-endemic region of Russia, where NPC is rarely diagnosed. The obtained data show structural and functional similarities of LMP1 variants in the two groups of patients and, accordingly, a genetic relationship of EBV strains persisting in these patients. Our work suggests that in non-endemic regions any EBV strain with any structure of LMP1 may become the etiologic agent of NPC. However, based on modem concepts, the cancer can occur only if EBV-infected persons have a unique pattern of HLA associated with a high sensitivity to the development of NPC combined with exposure to harmful environmental factors (chemical or physical carcinogens) and lifestyle.
Kormilitsyna MI, Korenberg EI, Kovalevskii YV
… +1 more, Meshcherakova I S
Mol Gen Mikrobiol Virusol
· 2016 Sep · PMID 30380209
The ticks Ixodes trianguliceps (140 nymph pool and 211 adults) collected from small forest mammals in the forests of the Middle Urals (Chusovskoy district of the Perm Region) were tested using real-time PCR for the prese...The ticks Ixodes trianguliceps (140 nymph pool and 211 adults) collected from small forest mammals in the forests of the Middle Urals (Chusovskoy district of the Perm Region) were tested using real-time PCR for the presence of Francisella tularensis DNA. Using the target gene 16S rRNA, the locus size 1165-1170 bp Francisella DNA was detected in 12 adults and 4 pools of nymphs. DNA-positive samples from 17 individuals from 128 adults and in 16 of 89 nymph pools were additionally detected by amplification of a shorter locus of the same gene (221-222 bp). All 49 16S rRNA gene-positive samples of real-time Taqman PCR assays directed against the tul4 (lpnA) gene locus and ISFtu2 element were identified as F. tularensis. These data suggest the possible involvement of the ticks I. trianguliceps in the circulation of the causative agent of tularemia in the natural foci of the forest type.
Nefedchenko AV, Shikov AN, Glotov AG
… +5 more, Glotova TI, Ternovoy VA, Agafonov AP, Sergeev AN, Donchenko NA
Mol Gen Mikrobiol Virusol
· 2016 Sep · PMID 30380208
The results of development of a method for detection and genotyping of the bacteria Pasteurella multocida capsular five groups and Mannheimia haemolytica Al based on the multiplex polymerase chain reaction (PCR) with ele...The results of development of a method for detection and genotyping of the bacteria Pasteurella multocida capsular five groups and Mannheimia haemolytica Al based on the multiplex polymerase chain reaction (PCR) with electrophoretic detection are submitted. Diagnostic sensitivity of the developed method was 103 CFU/ml in the study of the pure cultures and 105 CFU/g in the study of biological material. A study of 260 samples of biological material from infected animals revealed Pasteurella multocida in 50.0%, and Mannheimia haemolytica in 11.2% of the investigated samples. Circulation among the tested livestock of capsular groups B and E of Pasteurella multocida was not revealed. The majority of the tested samples contained group A, in some cases, group D, and, in one case, group F. On the basis of the phylogenetic analysis circulation of two different genetic types of Pasteurella multocida of the capsular group A was revealed.
Mol Gen Mikrobiol Virusol
· 2016 Sep · PMID 30380207
One of the main questions-in the study of the unisexual (parthenogenetic) species of vertebrates is the determination of their genetic diversity. Nuclear and mitochondrial genetic markers can be used for this purpose. On...One of the main questions-in the study of the unisexual (parthenogenetic) species of vertebrates is the determination of their genetic diversity. Nuclear and mitochondrial genetic markers can be used for this purpose. One of the most effective genetic markers is the microsatellite DNA, which mutates at a high rate. Development and characteristics of such markers are necessary in studies of parthenogenetic species. In this work, the analysis of the allele polymorphism of three microsatellite loci was performed for the first time via locus-specific PCR in the populations of parthenogenetic species Darevskia rostombekovi (n = 42) and bisexual parental species D. raddei (n = 6) and D. portschinskii (n = 6). All examined individuals of the parthenogenetic D. rostombekovi were heterozygous. Two to five alleles, depending on the locus, were found in the studied populations of the parthenogenetic species. It was shown that the differences were due to the varying structure of the microsatellite cluster and to single nucleotide substitutions at fixed distances in the DNA regions adjacent to the cluster. The allele structure variations form haplotype markers specific for each allele and inherited from the parental bisexual species. It was determined which alleles of the parthenogenetic species were inherited from the maternal species and which from the paternal species. Characteristics of distribution, frequency of occurrence, and combination of alleles of microsatellite loci, which determine the distinctive features of each D. rostombekovi population were obtained. The data can be used in the future to determine the clonal diversity and possible ways of its formation in the populations of the parthenogenetic species D. rostombekovi.
Mol Gen Mikrobiol Virusol
· 2016 Sep · PMID 30380206
In highly virulent strains of Yersinia pestis, the porin gene border- ing pigmentation (pgm) locus was observed to be usually broken by IS100. In this case, the pgm locus that carries virulence genes (high pathogenicity...In highly virulent strains of Yersinia pestis, the porin gene border- ing pigmentation (pgm) locus was observed to be usually broken by IS100. In this case, the pgm locus that carries virulence genes (high pathogenicity island) and biofilm formation genes (hms operon) is flanked by direct copies of IS100, which can cause its destabilization. We studied the prevalence of the intact and dis- rupted porin genes among 240 strains of Y. pestis from 39 natural centers in Russia and abroad, and 68 strains of Yersinia pseudotuberculosis from different geographical regions. The majority of the highly virulent Y. pestis strains and some phylogenetic lines of Y. pseudotuberculosis 0:1 serotype contain disrupted porin genes. At the same time, deletion of the pgm locus by flanking IS100 in Y pseudotuberculosis is impossible, because IS100 is integrated in the porin gene in the reverse orientation as compared to Y pestis. The porin genes are intact in all Y pestis strains with low epidemic importance and some phylogenetic lines of highly virulent Y pestis strains from some desert foci and Caspian sandy focus, as well as most strains of Y pseudotuberculosis 0:1 serotype. Less virulent strains of Y pseudotuberculosis 0:3 serotype revealed extensive deletion, which included the porin gene and a portion of the gene astE. The nucleotide sequence of the porin genes in Y pestis and Y pseudotuberculosis strains from different geographical regions are identical. Three alleles of the porin gene differ solely by the site of integration and orientation of IS 100 or by the lack of integration. The nucleotide sequence of IS 100, embedded in the porin gene of Yersinia, has minor differences only in two Y pestis strains isolated in America. Low frequency of Hms- mutations correlates with the intact condition of the porin gene in Y pestis. This correlation is absent in Y pseudotuberculosis.
Zhdanova SN, Ogarkov OB, Alexeeva GI
… +5 more, Vinokurova MK, Sinkov VV, Astaf'ev VA, Savilov ED, Kravchenko AF
Mol Gen Mikrobiol Virusol
· 2016 Sep · PMID 30380205
The population structure of the M. tuberculosis in Yakutia was estimated by the MIRU-VNTR method of 24 loci genotyping. 199 strains from 199 patients with pulmonary tuberculosis were tested. The greatest number of the st...The population structure of the M. tuberculosis in Yakutia was estimated by the MIRU-VNTR method of 24 loci genotyping. 199 strains from 199 patients with pulmonary tuberculosis were tested. The greatest number of the strains (34.2%, 68/199) belonged to the genotype Beijing. The significant predominance (X² = 15.5; p < 0.001) of the multidrug and extensively drug-resistance (MDR/XDR) among the isolates of Beijing genotype was revealed in subtype CC2/ W148 - 9.5% (19/199). Strains of the genotype S (15.6%, 31/199) were the second most common genotype after Beijing. The majority of S-strains had an identical profile 233325153325141344222372. S genotype strains also significantly more frequently carried the MDR/ XDR (X² = 59.8;p<0.001) among non-Beijing isolates. The genotype strain Ural ranks the third in the prevalence - 10.0% (20/199). The strains belonging to the family LAM (8.5%, 17/199) had considerable genetic heterogeneity. A great genetic diversity was also found in minor genotypes T and Haarlem. A phylogenetic reconstruction of the epidemic spread of the S-genotype and subtype CC2/W148 of the Beijing genotype in Yakutia was performed with estimation of the probable time of origin in the scale proposed by Merker M. et al. (2015). It was shown that the strains of the subtype CC2/W148 had been formed from four distinct phylogenetic sublines in recent historical period (XX century). It was estimated that phylogenetic relationships accounted for 30 MIRU-VNTR profiles of S-strains from Yakutia and 31 reference S-profiles from Europe and Canada. The profiles of the S-genotype from Yakutia form a phylogenetically compact group, indicating that all evolutionary history of these strains happened in the Sakha Republic. The time of the ancestral S-genotype spreading in Yakutia was estimated to be in the range from 300 to 600 years.
Evseeva VV, Platonov ME, Govorunov IG
… +5 more, Efremenko DV, Kuznetsova IV, Dentovskaya SV, Kulichenko AN, Anisimov AP
Mol Gen Mikrobiol Virusol
· 2016 · PMID 27183721
Comparative analysis of the MLVA25- and MLVA7-typing ability to evaluate focal belonging of Y. pestis strains by the example of bv. medievalis isolates from the Central-Caucasian highland natural plague focus was carried...Comparative analysis of the MLVA25- and MLVA7-typing ability to evaluate focal belonging of Y. pestis strains by the example of bv. medievalis isolates from the Central-Caucasian highland natural plague focus was carried out. The MLVA25-types of-82 isolates from this area were determined and included into the database containing information on 949 Y. pestis strains from other natural foci of Russia and other countries. Categorical-UPGMA dendrograms were created on the bases of the data concerning all 25 VNTR loci or only seven of them, which were recommended by the experts of the Russian Research Anti-Plague Institute "Microbe" for differentiation of the Y. pestis strains according to their affiliation to specific foci. The obtained data indicated greater possibility of diagnostic mistakes in the case of the MLVA7-typing and supported expediency of division of the Central-Caucasian highland natural plague focus into two sub-foci.
Bondareva OS, Savchenko SS, Tkachenko GA
… +3 more, Ledeneva ML, Lemasova LV, Antonov VA
Mol Gen Mikrobiol Virusol
· 2016 · PMID 27183720
Development of the genotyping methods of glanders agent is urgent due to its high pathogenicity, lack of effective preventive measures and threat of the use of Burkholderia mallei as a biological weapon. In this work we...Development of the genotyping methods of glanders agent is urgent due to its high pathogenicity, lack of effective preventive measures and threat of the use of Burkholderia mallei as a biological weapon. In this work we proposed a scheme for the typing of the B. mallei strains based on different region analysis (DFR). The choice of variable loci differentially presented in various strains of glanders agents was performed by analyzing annotated whole-genome sequences of the B. mallei strains. Primers and fluorescence probes were designed for 9 selected loci. The amplification conditions for different regions were optimized in two variants: with electrophoretic detection and hybridization-fluorescence detection in the strip format. The possibility of applying the DFR analysis to genetic characterization of strains was assessed in 14 B. mallei strains. The genetic profiles of the studied B. mallei strains revealed that the developed DFR-typing scheme was characterized by high discrimination power (Hunter-Gaston index value was 0.92), reproducibility, rapidity, easy interpretation, and applicability for epidemiological surveillance of glanders.
Vyazovaya AA, Mokrousov IV, Zhuravlev VY
… +5 more, Solovieva NS, Otten TF, Manicheva OA, Vishnevsky BI, Narvskaya OV
Mol Gen Mikrobiol Virusol
· 2016 · PMID 27183719
The goal of this work was to study the genotypic characteristics of the multidrug-resistant (MDR, i.e., resistant to at least rifampicine and isoniazid) Mycobacterium tuberculosis strains isolated in 2011-2012 from tuber...The goal of this work was to study the genotypic characteristics of the multidrug-resistant (MDR, i.e., resistant to at least rifampicine and isoniazid) Mycobacterium tuberculosis strains isolated in 2011-2012 from tuberculosis (TB) patients in the Northwest Russia. Spoligotyping of 195 M. tuberculosis isolates identified 14 different spoligotypes and assigned isolates to the genetic families Beijing (n = 162, 83%), LAM (n = 15), H3/URAL (n = 14), as well as T, Haarlem and X. Spoligotypes SIT1 (Beijing), SIT42 (LAM) and SIT262 (H3/URAL) were the most prevalent. Irrespective to the genotype, all the isolates were resistant to streptomycin. The multidrug resistance was accompanied by the resistance to ethionamide (56%), amikacin (31%), kanamycin (40%), and capreomycin (33%). The ethambutol resistance was found in 71% (n = 115) and 42% (n = 14) of the Beijing and non-Beijing strains, respectively (p < 0.05). In conclusion, the multidrug resistant M. tuberculosis population circulating in the Northwest Russia continues to be dominated by the Beijing family strains.
Shibaeva AV, Ayvazova RA, Rebrikov DV
… +5 more, Trubnikova EV, Kudykina YK, Belyakova AV, Zaripova RS, Shevelev AB
Mol Gen Mikrobiol Virusol
· 2016 · PMID 27183718
The total of 54 patients with chronic periodontitis of different severity was tested using real-time PCR (Dentoflor kit). The group included 38 patients with chronic gastritis. For the first time, a higher prevalence of...The total of 54 patients with chronic periodontitis of different severity was tested using real-time PCR (Dentoflor kit). The group included 38 patients with chronic gastritis. For the first time, a higher prevalence of Treponema denticola in periodontium of males in comparison with females was demonstrated. The patients with chronic gastritis had more human genome DNA at their periodontium than healthy individuals. Non-parametric statistical analysis demonstrated high association of periodontium colonization with. T. forsythensis and T. denticola (but not Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia) with the severity of the chronic periodontitis.
The urgency of the staphylococcus research is due to its ability to cause severe infections: softtissue infections, endocarditis, sepsis, toxic shock syndrome, and food poisoning. Coagulase-positive Staphylococcus aureus...The urgency of the staphylococcus research is due to its ability to cause severe infections: softtissue infections, endocarditis, sepsis, toxic shock syndrome, and food poisoning. Coagulase-positive Staphylococcus aureus is the main infection agent of intrahospital infections. This agent has many factors of pathogenicity, which are well known. Among the coagulase-negative staphylococcus (CNS) strains, S. haemolyticus and S. epidermidis are clinically important, because they cause infections in patients with weak immune system. The mechanisms of the CNS pathogenicity are insufficiently understood. The goal of this work was to evaluate the potential pathogenicity of clinical strains of CNS from their capacity to create biofilms and the character of their interaction with human body cells by the example of the HT-29 cell culture. The research was carried out in laboratory strain S. aureus ATCC 29213 and clinical strains S. haemolyticus SH39, S. epidermidis SE36-1 isolated from the neonatal autopsy materials. The visual tests of biofilm formation by each strain and testing of the impact of the strains on the cell culture HT-29 was carried out in this work. The two species of CNS form biofilms at a higher rate than S. aureus. Upon incubation for 2 h of HT-29 cells with staphylococcus strains tested in this work, adhesion of bacteria on cell surface was observed. The adhesion was most pronounced in case of S. aureus ATCC 29213 and S. haemolyticus SH39. Upon 3 h of incubation with S. aureus ATCC 29213 and S. haemolyticus SH39, destruction of cell HT-29 monolayer was observed. The incubation for 24 h with the 3 strains tested in this work caused complete destruction of cell HT-29 monolayer. The maximal toxic effect on HT-29 cells was inherent in the strain S. haemolyticus SH39. The aggregate of the results obtained in this work indicates the presence of the pathogenicity factors in the strains S. haemolyticus SH39, which require additional research.
The facultative aerobic bacteria isolated from the mucosa of rectum in patients with colorectal cancer in the zone of malignant tumor and neighboring normal mucosa was studied using molecular-genetic methods. The species...The facultative aerobic bacteria isolated from the mucosa of rectum in patients with colorectal cancer in the zone of malignant tumor and neighboring normal mucosa was studied using molecular-genetic methods. The species attribution of bacteria was implemented using the cultural-morphological analysis and sequencing of the 16S rRNA locus. The microorganisms with the intraepithelial invasion to rectal mucosa isolated were identified as representatives of the adherent-invasive (AIEC) subgroup of Escherichia coli and species Klebsiella pneumonia. The molecular analysis by genetic determinants controlling adhesive, hemolytic, and toxigenic activity revealed that some bacterial isolates were able to produce toxins with potential cancerogenic activity (e.g., colibactin and cytotoxic necrotic factor I). Certain bacterial species isolated from malignant and normal rectum epithelium of the same patient demonstrated no difference between analyzed factors of toxigenicity.