Bacterial interference in the nasopharynx and nasal cavity of sinusitis prone and non-sinusitis prone children.

The aim of this study was to compare the frequency of recovery of potential pathogens and aerobic and anaerobic interfering bacteria in the nasopharynx and nasal cavity of sinusitis prone (SP) children, with their recovery in non-sinusitis prone (N-SP) children. Nasopharyngeal and nasal cultures were taken from 20 SP and 20 N-SP children. Potential pathogens and aerobic and anaerobic bacteria with interfering capabilities against these micro-organisms were identified. Twenty-one potential pathogens (1.05 patient) were isolated from nasopharyngeal cultures from 14 of the 20 SP children, and 10 (0.5 patient) were recovered from 6 of the 20 NSP (p < 0.05). Bacterial interference between two aerobic (alpha and non-haemolytic streptococci) and two anaerobic species (Prevotella and Peptostreptococcus species) and four potential pathogens was observed. Bacterial interference was noted in 64 instances against 4 potential pathogens by 24 normal flora isolates that were recovered from 7 of the SP group and in 144 instances by 47 isolates from 18 of the NSP group (p < 0.05). Nineteen potential pathogens (0.95/patient) were isolated from nasal cultures of 13 of the 20 SP children and 8 (0.4/patient) were recovered from 5 of the 20 NSP (p < 0.05). Bacterial interference by similar micro-organisms was noted in 21 instances by 9 normal flora isolates that were recovered from 5 of the SP group, and in 63 instances by 26 isolates from 15 of the NSP group (p < 0.05). Our findings illustrate for the first time that the nasopharyngeal and nasal flora of NSP children contains more aerobic and anaerobic micro-organisms with interfering capability and less potential pathogens than that of SP children.