Identification and antimicrobial susceptibility testing of Streptococcus agalactiae associated urinary tract infections using VITEK 2 system
Abstract
Background and Objectives: As a Gram-positive bacterium, Streptococcus agalactiae or Group B Streptococcus (GBS) is normally found as a transient flora of the gastrointestinal and genitourinary tracts of women. The high prevalence of GBS in the urethra warrants investigation of UTIs and antibiotic resistance frequency associated with GBS. Given the paucity of research on antibiotic resistance of GBS in Iran, the present study investigated the UTIs associated with GBS and the antibiotic susceptibility patterns associated with GBS.
Materials and Methods: This study included 65 GBS strains collected from urine samples obtained from the Bouali Laboratory Complex, one of the largest laboratories in western Iran. VITEK 2 GP ID cards were used to identify all GBS isolates. VITEK 2 susceptibility testing for Gram-positive bacteria was performed according to the manufacturer's instructions using the AST-ST card. MIC method was performed after the detection of GBS strains.
Results: We found that 53 (81.5%) of the GBS isolates showed resistance to tetracycline; 47 (72.3%), 40 (61.5%), and 30 (46.15%) of these had a resistance to erythromycin, clindamycin and ampicillin respectively.
Conclusion: In the present study, the VITEK 2 system was validated as a user-friendly system that can serve as a rapid and accurate tool for identification and antimicrobial susceptibility testing of GBS.
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23. Kadri SS. Key takeaways from the US CDC’s 2019 antibiotic resistance threats report for frontline providers. Crit Care Med 2020; 48: 939-945.
24. Melo SC, Santos NC, Oliveira M, Scodro RB, Cardoso RF, Pádua RA, et al. Antimicrobial susceptibility of Streptococcus agalactiae isolated from pregnant women. Rev Inst Med Trop Sao Paulo 2016; 58: 83.
25. Tazi A, Réglier-Poupet H, Raymond J, Adam J-M, Trieu-Cuot P, Poyart C. Comparative evaluation of VITEK 2® for antimicrobial susceptibility testing of group B Streptococcus. J Antimicrob Chemother 2007; 59: 1109-1113.
26. Clinical and Laboratory Standard Institute (CLSI) (2010). Performance Standards for Antimicrobial Susceptibility Testing; Twentieth Informational Supplement. CLSI Document M100-S20. Wayne, Pennsylvania.
27. Kowalska-Krochmal B, Dudek-Wicher R. The Minimum inhibitory concentration of antibiotics: Methods, Interpretation, clinical relevance. Pathogens 2021; 10: 165.
28. Lowman W. Clinical application of Vitek-derived minimum inhibitory concentration values: Proof of concept study. S Afr J Infect Dis 2023; 38: 498.
29. Mousavi SM, Nasaj M, Hosseini SM, Arabestani MR. Survey of strain distribution and antibiotic resistance pattern of group B streptococci (Streptococcus agalactiae) isolated from clinical specimens. GMS Hyg Infect Control 2016; 11: Doc18.
30. Raabe VN, Shane AL. Group B streptococcus (Streptococcus agalactiae). Microbiol Spectr 2019; 7: 10.1128/microbiolspec. gpp3-0007-2018.
31. Gizachew M, Tiruneh M, Moges F, Tessema B. Streptococcus agalactiae maternal colonization, antibiotic resistance and serotype profiles in Africa: a meta-analysis. Ann Clin Microbiol Antimicrob 2019; 18: 14.
32. do Nascimento CS, Dos Santos NFB, Ferreira RCC, Taddei CR. Streptococcus agalactiae in pregnant women in Brazil: prevalence, serotypes, and antibiotic resistance. Braz J Microbiol 2019; 50: 943-952.
33. bornasi H, ghaznavi-Rad E, fard-mousavi N, zand S, abtahi H. Antibiotic resistance profile and capsular serotyping of Streptococcus agalactiae isolated from pregnant women between 35 to 37 weeks of pregnancy. Koomesh 2016; 17: 352-357.
34. Zakerifar M, Kaboosi H, Goli HR, Rahmani Z, Peyravii Ghadikolaii F. Antibiotic resistance genes and molecular typing of Streptococcus agalactiae isolated from pregnant women. BMC Pregnancy Childbirth 2023; 23: 43.
35. Liu Z, Jiang X, Li J, Ji W, Zhou H, Gong X, et al. Molecular characteristics and antibiotic resistance mechanisms of clindamycin-resistant Streptococcus agalactiae isolates in China. Front Microbiol 2023; 14: 1138039.
36. Jones S, Newton P, Payne M, Furfaro L. Epidemiology, antimicrobial resistance, and virulence determinants of group b Streptococcus in an Australian setting. Front Microbiol 2022; 13: 839079.
37. Prevention of group B Streptococcal Early-Onset disease in Newborns: ACOG committee opinion, number 797. Obstet Gynecol 2020; 135(2): e51-e72.
38. Emaneini M, Mirsalehian A, Beigvierdi R, Fooladi AAI, Asadi F, Jabalameli F, et al. High incidence of macrolide and tetracycline resistance among Streptococcus agalactiae strains isolated from clinical samples in Tehran, Iran. Maedica (Bucur) 2014; 9: 157-161.
39. Malek-Jafarian M, Hosseini F-S, Ahmadi A-R. Pattern of infection and antibiotic activity among Streptococcus agalactiae isolates from adults in Mashhad, Iran. Rep Biochem Mol Biol 2015; 3: 89-93.
2. Shabayek S, Spellerberg B. Group B streptococcal colonization, molecular characteristics, and epidemiology. Front Microbiol 2018; 9: 437.
3. Cheng P-J, Chueh H-Y, Liu C-M, Hsu J-J, Soong Y-K. Risk factors for recurrence of group B streptococcus colonization in a subsequent pregnancy. Obstet Gynecol 2008; 111: 704-709.
4. Simonsen KA, Anderson-Berry AL, Delair SF, Davies HD. Early-onset neonatal sepsis. Clin Microbiol Rev 2014; 27: 21-47.
5. Piccinelli G, Biscaro V, Gargiulo F, Caruso A, De Francesco MA. Characterization and antibiotic susceptibility of Streptococcus agalactiae isolates causing urinary tract infections. Infect Genet Evol 2015; 34: 1-6.
6. Edwards MS, Baker CJ. Group B streptococcal infections in elderly adults. Clin Infect Dis 2005; 41: 839-847.
7. Francois Watkins LK, McGee L, Schrag SJ, Beall B, Jain JH, Pondo T, et al. Epidemiology of invasive group B streptococcal infections among nonpregnant adults in the United States, 2008-2016. JAMA Intern Med 2019; 179: 479-488.
8. Graux E, Hites M, Martiny D, Maillart E, Delforge M, Melin P, et al. Invasive group B Streptococcus among non-pregnant adults in Brussels-Capital Region, 2005–2019. Eur J Clin Microbiol Infect Dis 2021; 40: 515-523.
9. Navarro-Torné A, Curcio D, Moïsi JC, Jodar L. Burden of invasive group B Streptococcus disease in non-pregnant adults: A systematic review and meta-analysis. PLoS One 2021; 16(9): e0258030.
10. Sendi P, Johansson L, Norrby-Teglund A. Invasive group B Streptococcal disease in non-pregnant adults: a review with emphasis on skin and soft-tissue infections. Infection 2008; 36: 100-111.
11. Klein RD, Hultgren SJ. Urinary tract infections: microbial pathogenesis, host–pathogen interactions and new treatment strategies. Nat Rev Microbiol 2020; 18: 211-226.
12. Bazaid AS, Aldarhami A, Gattan H, Barnawi H, Qanash H, Alsaif G, et al. Antibiogram of Urinary Tract Infections and Sepsis among Infants in Neonatal Intensive Care Unit. Children (Basel) 2022; 9: 629.
13. Ulett KB, Benjamin Jr WH, Zhuo F, Xiao M, Kong F, Gilbert GL, et al. Diversity of group B Streptococcus serotypes causing urinary tract infection in adults. J Clin Microbiol 2009; 47: 2055-2060.
14. Matsubara K, Yamamoto G. Invasive group B streptococcal infections in a tertiary care hospital between 1998 and 2007 in Japan. Int J Infect Dis 2009; 13: 679-684.
15. Ho C-M, Chi C-Y, Ho M-W, Chen C-M, Liao W-C, Liu Y-M, et al. Clinical characteristics of group B streptococcus bacteremia in non-pregnant adults. J Microbiol Immunol Infect 2006; 39: 396-401.
16. Hayes K, O’Halloran F, Cotter L. A review of antibiotic resistance in Group B Streptococcus: the story so far. Crit Rev Microbiol 2020; 46: 253-269.
17. Genovese C, D’Angeli F, Di Salvatore V, Tempera G, Nicolosi D. Streptococcus agalactiae in pregnant women: serotype and antimicrobial susceptibility patterns over five years in Eastern Sicily (Italy). Eur J Clin Microbiol Infect Dis 2020; 39: 2387-2396.
18. Kamińska D, Ratajczak M, Nowak-Malczewska DM, Karolak JA, Kwaśniewski M, Szumala-Kakol A, et al. Macrolide and lincosamide resistance of Streptococcus agalactiae in pregnant women in Poland. Sci Rep 2024; 14: 3877.
19. Motallebirad T, Fazeli H, Ghahiri A, Shokri D, Jalalifar S, Moghim S, et al. Prevalence, population structure, distribution of serotypes, pilus islands and resistance genes among erythromycin-resistant colonizing and invasive Streptococcus agalactiae isolates recovered from pregnant and non-pregnant women in Isfahan, Iran. BMC Microbiol 2021; 21: 139.
20. Capanna F, Emonet SP, Cherkaoui A, Irion O, Schrenzel J, de Tejada B. Antibiotic resistance patterns among group B Streptococcus isolates: implications for antibiotic prophylaxis for early-onset neonatal sepsis. Swiss Med Wkly 2013; 143: w13778.
21. Bolukaoto JY, Monyama CM, Chukwu MO, Lekala SM, Nchabeleng M, Maloba MR, et al. Antibiotic resistance of Streptococcus agalactiae isolated from pregnant women in Garankuwa, South Africa. BMC Res Notes 2015; 8: 364.
22. Heelan JS, Hasenbein ME, McAdam AJ. Resistance of group B streptococcus to selected antibiotics, including erythromycin and clindamycin. J Clin Microbiol 2004; 42: 1263-1264.
23. Kadri SS. Key takeaways from the US CDC’s 2019 antibiotic resistance threats report for frontline providers. Crit Care Med 2020; 48: 939-945.
24. Melo SC, Santos NC, Oliveira M, Scodro RB, Cardoso RF, Pádua RA, et al. Antimicrobial susceptibility of Streptococcus agalactiae isolated from pregnant women. Rev Inst Med Trop Sao Paulo 2016; 58: 83.
25. Tazi A, Réglier-Poupet H, Raymond J, Adam J-M, Trieu-Cuot P, Poyart C. Comparative evaluation of VITEK 2® for antimicrobial susceptibility testing of group B Streptococcus. J Antimicrob Chemother 2007; 59: 1109-1113.
26. Clinical and Laboratory Standard Institute (CLSI) (2010). Performance Standards for Antimicrobial Susceptibility Testing; Twentieth Informational Supplement. CLSI Document M100-S20. Wayne, Pennsylvania.
27. Kowalska-Krochmal B, Dudek-Wicher R. The Minimum inhibitory concentration of antibiotics: Methods, Interpretation, clinical relevance. Pathogens 2021; 10: 165.
28. Lowman W. Clinical application of Vitek-derived minimum inhibitory concentration values: Proof of concept study. S Afr J Infect Dis 2023; 38: 498.
29. Mousavi SM, Nasaj M, Hosseini SM, Arabestani MR. Survey of strain distribution and antibiotic resistance pattern of group B streptococci (Streptococcus agalactiae) isolated from clinical specimens. GMS Hyg Infect Control 2016; 11: Doc18.
30. Raabe VN, Shane AL. Group B streptococcus (Streptococcus agalactiae). Microbiol Spectr 2019; 7: 10.1128/microbiolspec. gpp3-0007-2018.
31. Gizachew M, Tiruneh M, Moges F, Tessema B. Streptococcus agalactiae maternal colonization, antibiotic resistance and serotype profiles in Africa: a meta-analysis. Ann Clin Microbiol Antimicrob 2019; 18: 14.
32. do Nascimento CS, Dos Santos NFB, Ferreira RCC, Taddei CR. Streptococcus agalactiae in pregnant women in Brazil: prevalence, serotypes, and antibiotic resistance. Braz J Microbiol 2019; 50: 943-952.
33. bornasi H, ghaznavi-Rad E, fard-mousavi N, zand S, abtahi H. Antibiotic resistance profile and capsular serotyping of Streptococcus agalactiae isolated from pregnant women between 35 to 37 weeks of pregnancy. Koomesh 2016; 17: 352-357.
34. Zakerifar M, Kaboosi H, Goli HR, Rahmani Z, Peyravii Ghadikolaii F. Antibiotic resistance genes and molecular typing of Streptococcus agalactiae isolated from pregnant women. BMC Pregnancy Childbirth 2023; 23: 43.
35. Liu Z, Jiang X, Li J, Ji W, Zhou H, Gong X, et al. Molecular characteristics and antibiotic resistance mechanisms of clindamycin-resistant Streptococcus agalactiae isolates in China. Front Microbiol 2023; 14: 1138039.
36. Jones S, Newton P, Payne M, Furfaro L. Epidemiology, antimicrobial resistance, and virulence determinants of group b Streptococcus in an Australian setting. Front Microbiol 2022; 13: 839079.
37. Prevention of group B Streptococcal Early-Onset disease in Newborns: ACOG committee opinion, number 797. Obstet Gynecol 2020; 135(2): e51-e72.
38. Emaneini M, Mirsalehian A, Beigvierdi R, Fooladi AAI, Asadi F, Jabalameli F, et al. High incidence of macrolide and tetracycline resistance among Streptococcus agalactiae strains isolated from clinical samples in Tehran, Iran. Maedica (Bucur) 2014; 9: 157-161.
39. Malek-Jafarian M, Hosseini F-S, Ahmadi A-R. Pattern of infection and antibiotic activity among Streptococcus agalactiae isolates from adults in Mashhad, Iran. Rep Biochem Mol Biol 2015; 3: 89-93.
| Files | ||
| Issue | Vol 17 No 2 (2025) | |
| Section | Original Article(s) | |
| DOI | https://doi.org/10.18502/ijm.v17i2.18383 | |
| Keywords | ||
| Identification; Streptococcus agalactiae; Urinary tract infections; VITEK 2 System | ||
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How to Cite
1.
Mohajeri P, Faridafshar H, Kooti S. Identification and antimicrobial susceptibility testing of Streptococcus agalactiae associated urinary tract infections using VITEK 2 system. Iran J Microbiol. 2025;17(2):239-245.
