RESUMEN
Pseudomonas aeruginosa is one of the most problematic pathogens in medical institutions, which may be due to the ability of this microorganism to exist in a biofilm, which increases its resistance to antimicrobials, as well as its prevalence and survival ability in the external environment. This work aimed to evaluate the antimicrobial susceptibility of P. aeruginosa strains in planktonic and biofilm forms. We studied 20 strains of P. aeruginosa collected during 2018-2021 by specialists from the Laboratory of Microbiome and Microecology of the Scientific Centre for Family Health and Human Reproduction Problems. The identification of strains was carried out using test systems for differentiating gram-negative non-fermenting bacteria (NEFERMtest 24 Erba Lachema s.r.o., Czech Republic), and confirmed by mass spectrometric analysis and 16S rRNA gene sequencing. Antimicrobial activity was assessed by the degree of inhibition of cell growth in planktonic and biofilm forms (on a flat-bottomed 96-well plastic immunological plate). All clinical isolates of P. aeruginosa were biofilm formers, 47.6 % of the isolates were weak biofilm formers, and 52.4 % of the isolates were moderate biofilm formers. Planktonic cells and the forming biofilm of the tested P. aeruginosa strains were carbapenems-resistant. Biofilm formation was suppressed in more than 90 % of cases by the agents of the cephalosporin and aminoglycoside groups. Antimicrobial susceptibility of P. aeruginosa strains in the formed biofilm was significantly lower (p < 0.05). Carbapenems and cephalosporins did not affect the mature biofilms of the tested P. aeruginosa strains in more than 60 % of cases. Only non-beta-lactam antibiotics (ciprofloxacin and amikacin) suppressed the growth of planktonic cells and destroyed the mature biofilm. The revealed differences in the effect of the tested antimicrobials on the P. aeruginosa strains biofilms correlate with resistance to a number of antibiotics. To prevent biofilm formation in the hospital strains of P. aeruginosa, the use of ceftazidime may be recommended, and antimicrobials such as ciprofloxacin and amikacin may be used to affect mature biofilms of P. aeruginosa.
RESUMEN
Functional gastrointestinal disorders (FGIDs) in children and adolescents are one of the most common pathologies of the digestive tract. The aim of the study was to study the structure of the colon microbiota in obese adolescents and to establish its relationship with the clinical manifestations of the disease FGIDs. The study included 20 adolescents aged 11-17 years. The main group included 13 adolescents with a clinically confirmed diagnosis of obesity (the standard deviation of the body mass index (SDS BMI) is more than 2,0) in combination with FGIDs. The control group consisted of 7 adolescents with normal body weight and no abdominal complaints (SDS BMI=0,66). Clinical symptoms from the bowel re diagnosed on the basis of the Rome IV. The consistency of feces was evaluated using the Bristol Stool Form Scale. The study of biological material was carried out by standard bacteriological methods. It is shown that in adolescents with obesity and FGIDs, there is a decrease in the concentration of representatives of bifidoflora, an increase in the microbial density of Escherichia coli with altered properties and an excessive growth of potentially pathogenic enterobacteria. It is established that the presence of conditionally pathogenic bacteria is sem. Enterobacteriaceae is associated with abdominal pain during defecation. In obese adolescents in the group with unformed stools, Clostridium spp was recorded as part of the intestinal microbiota.
Asunto(s)
Enfermedades Gastrointestinales , Microbioma Gastrointestinal , Microbiota , Obesidad Infantil , Adolescente , Niño , Enfermedades Gastrointestinales/diagnóstico , HumanosRESUMEN
We compared the effects of disinfectants on biofilms of 10 Pseudomonas aeruginosa strains isolated from different loci of patients with purulent-septic infections. Identification was carried out by standard bacteriological methods. To substantiate the prospects of using in hospitals and to assess the effect of disinfectants on P. aeruginosa biofilms, the following disinfectants were used in various concentrations: Sekusept Aktiv, A-DEZ, and Monitor Oxy. All clinical strains of P. aeruginosa showed the ability to form biofilms. Both oxygen-containing and quaternary ammonium compounds effectively inhibited the formation of biofilms. In more than 50% cases, disinfectants with different active ingredients did not destroy pre-formed of P. aeruginosa biofilms.
Asunto(s)
Biopelículas/efectos de los fármacos , Desinfectantes/farmacología , Oxidantes/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Compuestos de Amonio Cuaternario/farmacología , Adolescente , Carga Bacteriana , Biopelículas/crecimiento & desarrollo , Niño , Preescolar , Medios de Cultivo/química , Medios de Cultivo/farmacología , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Lactante , Masculino , Pruebas de Sensibilidad Microbiana , Infecciones por Pseudomonas/microbiología , Infecciones por Pseudomonas/patología , Pseudomonas aeruginosa/enzimología , Pseudomonas aeruginosa/crecimiento & desarrollo , Pseudomonas aeruginosa/aislamiento & purificación , Sepsis/microbiología , Sepsis/patologíaRESUMEN
The level of sensitivity of Klebsiella pneumoniae strains isolated from children of the first half of life with functional gastrointestinal disorders (FGID) to commercial bacteriophage preparations was assessed. The material was the feces of 67 children of the first half of life with FGID who are breastfed. Culture of K. pneumoniae isolated from faeces of children, amounted to two comparison groups, depending on the age of the patients. The first group included 43 K. pneumoniae strains isolated from the colon of children aged from birth to three months, in the second group - 24 strains, from children aged three to six months. The composition of the colon microbiota was studied using standard methods, and the results were evaluated in accordance with Industry Standard 91500.11.0004-2003. Identification of K. pneumoniae was performed by bacteriological methods. Determination of the level of lytic activity of K. pneumoniae, Klebsiella polyvalent and sextaphage bacteriophages to K. pneumoniae strains was conducted by the drip method (spot-test) according to clinical recommendations. It is shown that the formation of FGID symptoms in children correlates with age - the frequency of regurgitation decreased in children up to six months (from 23.3% to 4.2%) against the background of the formation of a symptom complex associated with defecation disorder. Bacteriological analysis showed that in General, phages show a low level of lytic activity, sensitivity to them Klebsiella also correlated with age and was higher in children of three to six months. Thus, in the first comparison group, the absence of Klebsiella lysis in relation to the Klebsiella pneumoniae bacteriophage was registered three times more often (30.2%, p<0.05) and twice less often (30.2%, p<0.05), the low level of lysis of K. pneumoniae strains to the Klebsiella polyvalent phage compared to the second group. The sensitivity of K. pneumoniae strains to sextaphage was comparable in comparison groups and varied from 2 to 10%. Thus, among the studied K. pneumoniae observed a low level of sensitivity to specific drugs - bacteriophage Klebsiella pneumoniae, Klebsiella polyvalent and sextaphage. This fact reflects the insufficient activity of phages and predicts low effectiveness of empirical phage therapy without elimination from the intestinal biocenosis of K. pneumoniae in children with FGID who are breastfed.
Asunto(s)
Bacteriófagos , Enfermedades Gastrointestinales , Microbiota , Niño , Colon , Humanos , Lactante , Klebsiella pneumoniaeRESUMEN
Opportunistic microorganisms in the gut biocenosis were studied in adolescents with normal body weight and obesity (patients consulted at the Clinical Department of Research Center of Family Health and Human Reproduction Problems). The biological material was studied by standard bacteriological methods, representatives of Enterobacteriaceae family were also characterized using metagenomic sequencing of V3-V4 variable regions of 16S gene rRNA. Gut microbiota of obese adolescents was unbalanced and was characterized by low levels of bifido- and lactoflora representatives, a spectrum of E. coli associations, and high prevalence of opportunistic microorganisms and their associations. Representatives of Enterobacteriaceae family were most often found in the gut microbiota of obese adolescents.
Asunto(s)
Microbiota/fisiología , Obesidad/microbiología , ARN Ribosómico 16S/genética , Enterobacteriaceae/genética , Enterobacteriaceae/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Microbioma Gastrointestinal/genética , Microbioma Gastrointestinal/fisiología , Genes de ARNr/genética , Genes de ARNr/fisiología , Microbiota/genéticaRESUMEN
The effect of bactericide Sekusept active (B SA), a peracetic acid-based preparation, on microbial strains, isolated from patients with severe infectious diseases who were treated in a regional children's multi-specialty hospital, was studied. Based on the biochemical identification, the strains were classified as gram-negative non-fermenting bacteria (22 strains), Enterobacteriaceae family (18 strains), and bacilli - 3 strains. The biocidal activity of B SA was evaluated by the degree of inhibition of the growth of bacterial cells, existing in the planktonic form and in the form of biofilm (on a flat-bottomed plastic immunological tablet). It was shown that all the studied strains had the ability to biofilm formation, most of them (67,4%) formed moderately pronounced biofilms, and non-fermenting bacteria had a particularly pronounced coefficient of biofilm formation. The selected concentrations of B CA inhibited the growth of planktonic cells, and the ability of bactericide to prevent the formation of biofilms depended on the concentration (the most effective concentrations were 0,8 and 3,0%). Sensitivity of the strains existed in the aged biofilm to the bactericide was significantly lower, especially resistant to this effect were biofilms formed by non-fermenting bacteria and representatives of fam. Enterobacteriaceae. Our results confirm the importance of testing the effectiveness of biocides not only in accordance with standard methods developed for microorganisms in planktonic form, but also for biofilms.