African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5211

Full Length Research Paper

Identification and quantitation of conjunctival aerobic bacterial flora from healthy residents at different ages in Southwest China

  Jing Liu, Jing Li, Jian Huo and Hanping Xie*
  Southwest Hospital, Southwest Eye Hospital, Third Military Medical University, Chongqing, China 400038, China.
Email: [email protected]

  •  Accepted: 20 January 2011
  •  Published: 04 February 2011



To identify and quantitate conjunctival aerobic bacterial flora from healthy residents of three age groups in Chongqing city, Southwest China. Samples taken with moist swabs from the lower fornix of bilateral eyes of 33 children (9.85 ± 0.57 years old), 31 youths (21.23 ± 0.88 years old), and 30 elders (72.97 ± 4.94 years old) respectively were tested for bacterial cultures. Positive cultures were identified and colony forming units (CFUs) were counted. Bacterial quantity was expressed as the number of CFUs divided by the weight difference of each sample transport swab-tube measured before and after the sample collection. The elders showed a higher isolation frequency (93.33%) of conjunctival aerobic bacteria than that of children (45.45%) and youths (50.00%), (P<0.01). Corynebacterium diphtheroid, Staphylococcus epidermidis and Staphylococcus aureus isolated from the elders all had a greater percentage. The elders also had a larger number of aerobic bacteria species per eye than did children and youths (P<0.01). Children showed a lower quantity of conjunctival aerobic bacterial flora than that of the other two groups (P<0.01). C. diphtheroid was the most numerous isolate from all the subjects. The quantity of C. diphtheroid became larger when residents grew older. S. epidermidis was the second most numerous bacteria in the groups of children and elders, and the elder group had a greater number of S. epidermidis than the children group (P<0.01). The number of species and quantity of conjunctival aerobic bacterial flora from the elders were larger than those from children and youths, which should be of concern to an ophthalmologist. 


Key words: Conjunctival sac, aerobic bacteria, age, quantitative analysis, microecology.