B grupas streptokoku biofilmu veidošanas spēja un antibakteriālās rezistences loma grūtniecības laikā
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Date
2021
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Rīgas Stradiņa universitāte
Rīga Stradiņš University
Rīga Stradiņš University
Abstract
Streptococcus agalactiae ir B grupas streptokoku (BGS) pārstāvis. Šie mikroorganismi 5 – 30% cilvēku, tostarp grūtnieču, pieder normālajai maksts un apakšējā gastrointestinālā trakta mikrobiotai. S. agalactiae ir nopietns riska faktors jaundzimušo sepses attīstībai pirmajā dzīves nedēļā. Kolonizācijas un infekcijas procesa attīstībā liela loma ir biofilmu veidošanas spējai, kā arī antibakteriālajai rezistencei. Biofilmas veidošana ir kā baktēriju aizsargfaktors, kas ne tikai pasargā no cilvēka imūnsistēmas atbildes reakcijas, bet arīdzan antibakteriālo līdzekļu iedarbības.
21 S. agalactiae celmu tīrkultūra tika iegūta no Nacionālā medicīnas servisa-laboratorijas (NMS), Paula Stradiņa klīniskās universitātes slimnīcas un Rīgas Austrumu klīniskās universitātes slimnīcas laboratorijas. Disku difūzijas metode antibakteriālās jutības noteikšanai tika veikta atbilstoši EUCAST v11.0 protokolam. Biofilmu kultivēšana tika veikta 96-bedrīšu mikrotitru platēs pēc Stepanovic et al protokola. Biofilmas veidošanās stiprums tika mērīts, nosakot optisko blīvumu, izmantojot optisko spektrofotometru. Robežvērtība katrai mikroplatei tika aprēķināta atsevišķi kā trīs standartnovirzes virs vidējās negatīvās kontroles vērtības. Eksperiments katram celmam tika veikts trīs atkārtojumos. Datu apstrāde tika veikta, izmantojot MS Excel v16.44, 2020.
Pēc 24 stundu kultivēšanas, sešiem celmiem piemita biofilmas veidošanas spēja, no kuriem četri celmi bija vājas biofilmas veidotāji, divi – vidēji spēcīgas. 15 celmiem netika novērota biofilmas veidošanas spēja. Trīs celmiem novēroja rezistenci pret benzilpencilīnu, trīs – pret klindamicīnu un eritromicīnu. Celms U006 bija rezistents pret benzilpenicilīnu un eritromicīnu. Celms U012 bija vidēji spēcīgas biofilmas veidotājs, kā arī rezistents pret benzilpenicilīnu. Celms U025 bija vidēji spēcīgas biofilmas veidotājs un rezistents pret klindamicīnu un eritromicīnu.
Starp izolētajiem S. agalactiae celmiem tika novērota biofilmu veidošanas spēja un antibakteriāla rezistence. Ņemot vērā pret penicilīniem rezistento celmu izdalīšanu, jāapsver rutīnas antibakteriālās jutības noteikšana pēc BGS pierādīšanas rektovaginālā uzsējumā. Biofilmu veidošanas spēju nepieciešams izvērtēt pēc ilgāka inkubācijas perioda, lai noteiktu tā ietekmi uz BGS kolonizāciju.
Streptococcus agalactiae is a member of group B streptococci (GBS). In 5-30% healthy women in reproductive age it is a part of normal vaginal and lower gastrointestinal tract microbiota. S. agalactiae is an important risk factor for neonatal sepsis in the first week of life. Biofilm formation and antibiotic resistance has a great role in S. agalactiae colonization and infection. Effect of antibacterial agents on biofilm structures is insufficient due to reduced bacterial metabolic activity and lowered penetration. In total, 21 pure cultures of S. agalactiae were obtained from Pauls Stradins Clinical University Hospital, Riga East Clinical University Hospital and NMS laboratory. To assess antibacterial susceptibility, disk diffusion test was applied according to EUCAST version 11.0, 2021. Biofilm cultivation in sterile 96-well plates over 24 hours was performed according to Stepanovic et al protocol. Optical density measurements were done after biofilm staining. The cut-off value (ODc) was separately established as three standard deviations (SDs) over the mean negative control value for each plate. Experiments were conducted in triplicate. Statistical analysis was performed using MS Excel 16.44, 2020. After 24 hour incubation period six strains were biofilm producers, from which four strains - weak producers, two strains – moderate, whereas 15 strains were biofilm non producers. Three strains were resistant to benzylpenicillin, three - to clindamycin and erythromycin, U006 - to benzylpenicillin and erythromycin. U012 strain was moderate biofilm producer and resistant to benzylpenicillin, U025 was moderate biofilm producer and resistant to clindamycin and erythromycin. Biofilm formation and antibacterial resistance was detected in isolated S. agalactiae strains. Therefore, such factors should be accounted in selection of proper antimicrobial regimen. Data obtained indicates that antibacterial susceptibility should be considered after confirmed GBS colonization. Biofilm formation should be investigated in prolonged incubation period to detect impact of GBS colonization.
Streptococcus agalactiae is a member of group B streptococci (GBS). In 5-30% healthy women in reproductive age it is a part of normal vaginal and lower gastrointestinal tract microbiota. S. agalactiae is an important risk factor for neonatal sepsis in the first week of life. Biofilm formation and antibiotic resistance has a great role in S. agalactiae colonization and infection. Effect of antibacterial agents on biofilm structures is insufficient due to reduced bacterial metabolic activity and lowered penetration. In total, 21 pure cultures of S. agalactiae were obtained from Pauls Stradins Clinical University Hospital, Riga East Clinical University Hospital and NMS laboratory. To assess antibacterial susceptibility, disk diffusion test was applied according to EUCAST version 11.0, 2021. Biofilm cultivation in sterile 96-well plates over 24 hours was performed according to Stepanovic et al protocol. Optical density measurements were done after biofilm staining. The cut-off value (ODc) was separately established as three standard deviations (SDs) over the mean negative control value for each plate. Experiments were conducted in triplicate. Statistical analysis was performed using MS Excel 16.44, 2020. After 24 hour incubation period six strains were biofilm producers, from which four strains - weak producers, two strains – moderate, whereas 15 strains were biofilm non producers. Three strains were resistant to benzylpenicillin, three - to clindamycin and erythromycin, U006 - to benzylpenicillin and erythromycin. U012 strain was moderate biofilm producer and resistant to benzylpenicillin, U025 was moderate biofilm producer and resistant to clindamycin and erythromycin. Biofilm formation and antibacterial resistance was detected in isolated S. agalactiae strains. Therefore, such factors should be accounted in selection of proper antimicrobial regimen. Data obtained indicates that antibacterial susceptibility should be considered after confirmed GBS colonization. Biofilm formation should be investigated in prolonged incubation period to detect impact of GBS colonization.
Description
Medicīna
Medicine
Veselības aprūpe
Health Care
Medicine
Veselības aprūpe
Health Care
Keywords
B grupas streptokoki, S. agalactiae, biofilmu veidošana, antibakteriālā rezistence, Group B streptococci, S. agalactiae, biofilm formation, antibacterial resistance