The presence of the pilus locus is a clonal property among pneumococcal invasive isolates

BMC Microbiology

Table 2 Association of the rlrA islet with antimicrobial resistance

Antibiotic	no. rlrA positive strains/no. resistant isolates (% rlrA positive strains)	no. rlrA positive strains/no. susceptible isolates (% rlrA positive strains)	OR(95% CI)^a	p
Penicillin ^b	69/113 (61)	59/370 (16)	8.27 (5.17 – 13.22)	< 10^-4
Erythromycin	23/48 (48)	105/435 (24)	2.89 (1.58 – 5.30)	0.0004
Tetracycline	16/38 (42)	112/445 (25)	2.16 (1.09 – 4.26)	0.023
Chloramphenicol	5/14 (36)	123/469 (26)	NS^c
Co-trimoxazole	74/106 (70)	54/377 (14)	13.83 (8.35 – 22.91)	< 10^-4
MDR ^d	22/42 (52)	106/441 (44)	3.48 (1.83 – 6.62)	< 10^-4

^aAn OR of > 1 indicates increased proportion of rlrA positive isolates whereas OR of < 1 indicates decreased proportion of rlrA positive isolates. Only statistically significant results (FDR < 0.05) are presented.
^b Both penicillin intermediate and fully resistant isolates were considered resistant for this analysis
^cNS – not significant
^dMDR – multidrug resistance defined as resistance to at least three different antimicrobial classes considering as resistant to penicillin both intermediate as well as fully resistant isolates

ISSN: 1471-2180