Osjetljivost odabranih komensalnih bakterija iz mikrobiote majčinog mlijeka na antibiotike

undergraduate thesis

• Title (english): The antibiotic susceptibility of selected commensal bacteria isolated from the human milk microbiota
• Author: Andrea Petrinić
• Mentor: Jasna Novak (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Antibiotic, Enzyme, Probiotic and Starter Cultures Technology); Zagreb
• Defense date and country: 2020-07-01, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Nutrition

Abstract

Majčino mlijeko je optimalna prehrana za novorođenče i izvor je esencijalnih nutrijenata, brojnih bioaktivnih sastojaka i prve mikrobiote koja kolonizira gastrointestalni trakt dojenčeta. Kako mikrobiota majčinog mlijeka ima presudnu ulogu u razvoju i zdravlju novorođenčeta, značajno je ispitati moguću pojavu antibiotičke rezistencije kod komensalnih bakterija. Stoga je cilj ovog rada bio ispitati osjetljivost odabranih sojeva komensalnih bakterija iz mikrobiote majčinog mlijeka na 9 različitih antibiotika metodom difuzije u agar. Za 25 komensalnih bakterija su pomoću E-testa određene i vrijednosti minimalne inhibicijske koncentracije (MIC) antibiotika. Metodom lančane reakcije polimeraze identificirani su geni koji kodiraju za rezistenciju na antibiotike. Iako je primjenom fenotipskih metoda ustanovljeno da većina antibiotika nije inhibirala rast komensalnih bakterija, primjenom PCR metode nisu detektirani amplikoni koji bi upućivali na prisutnost genetičkih determinanti antibiotičke rezistencije. Utvrđena je prisutnost rezistencije na vankomicin kod Lactobacillus sojeva, koja je karakteristična za bakterije iz ovog roda, a radi se o urođenoj rezistenciji. Kako je u genomu svih sojeva Staphylococcus epidermis AF4, AF5, MB6, MB12 i RS8 te kod Streptococcus oralis subsp. dentisani MB5, nakon PCR reakcije detektirana specifična DNA vrpca veličine 297 pb koja ukazuje na prisutnost bla gena, isključeni su iz daljnjih istraživanja.

Abstract (english)

Human breast milk is the optimal nutrition for infants, representing a rich source of the essential nutrients and diversity of bioactive compounds, as well as the child´s first intestinal microbiota. As the microbiota of breast milk plays a significant role in the development and health of the newborns, characterization of the antibiotic susceptibility profiles of commensal bacteria from the human milk microbiota is essential. Therefore, the present work aimed to examine the susceptibility of selected strains of commensal bacteria isolated from breast milk microbiota to different antibiotics by the disk diffusion agar method. For 25 commensal bacteria, the values of the minimum inhibitory concentration (MIC) of antibiotics were determined by the E - test. Antibiotic resistance genes were identified by the polymerase chain reaction (PCR) method. Although phenotypic methods showed that most of the antibiotics do not inhibit the growth of commensal bacteria, the amplicons that would indicate the presence of antibiotic resistance determinants were not detected by PCR. Lactobacillus strains were not susceptible to vancomycin, which is typical for bacteria of this genus, which is described as innate resistance. The genome of all Staphylococcus epidermis AF4, AF5, MB6, MB12 and RS8 and Streptococcus oralis subsp. dentisani MB5, appeared to cotain bla gene encoding the enzyme β-lactamase according to the presence of a specific band of 297 bp detected after PCR.

• Keywords: antibiotička rezistencija; komensalne bakterije; mikrobiota majčinog mlijeka
• Keywords (english): antibiotic resistance; commensal bacteria; human milk microbiota
• Language: croatian
• URN:NBN: urn:nbn:hr:159:495945
• Study programme: Title: Nutrition; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) nutricionizma (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-07-14 12:39:11