Potential bacterial involvement in the development of severe ROP

Investigators conducted a retrospective study of 114 premature infants (228 eyes) with a gestational age of 32 weeks or shorter. Image credit: ©Piman Khrutmuang – stock.adobe.com

A team of Polish researchers who analysed a potential association between positive bacterial cultures and severe retinopathy of prematurity (ROP) in very-low-birthweight premature infants may jointly become prognostic markers for the early development of ROP,¹ according to lead author Monika Modrzejewska, MD, from the Scientific Association of Students, II Department of Ophthalmology, Pomeranian Medical University, Szczecin, Poland.

The investigators speculated that because the causes responsible for the development of ROP are still unexplored, it is possible that perinatal inflammation may be an important factor in disease development.

They conducted a retrospective study in which 114 premature infants (228 eyes) with a gestational age of 32 weeks or shorter and a birthweight of 1,710 grams or less were included.

The children were divided into 2 groups. The examined group was comprised of 51 patients with severe ROP who had a mean birthweight of 852.7 grams and a mean gestational age of 26.3 weeks; these babies had been treated with diode laser or anti-vascular endothelial growth factor (VEGF) intravitreal injection. The control group included 63 patients who did not have ROP and had a mean birthweight of 1,313.9 grams and a gestational age of 28.8 weeks.

The researchers obtained microbiologic bacterial and fungal cultures of the ear, anus, bronchial throat and blood from the infants. The medical data and laboratory test results analysed to determine a correlation with ROP3 and A-ROP.

The results showed that 47% of babies in the examined group had positive bacterial tests compared with 23% of the controls.

The findings showed significant correlations between positive cultures obtained from the anus (p < 0.001), throat (p = 0.002) and blood (p = 0.001) and severe ROP, which requires diode laser and anti-VEGF treatment.

They also reported that significant inflammation markers, which are correlated with the development of severe ROP, were Klebsiella pneumoniae (p = 0.002) and coagulase-negative staphylococci (p < 0.001). Coagulase-negative staphylococci (p < 0.001), K. pneumoniae (p = 0.002), Maltophilia stenotrophomonas and Staphylococcus aureus (p = 0.005), and Enterobacter cloacae (p = 0.02 were the most frequent bacteria in severe ROP.

The findings also showed that high levels of white blood cells, C-reactive protein, lymphocytes and low thrombocytes were correlated sequentially with coagulase-negative staphylococci (odds ratio [OR], 2.3), M. stenotrophomonas (OR, 5.9); K. pneumoniae (OR, 3.1); and all positive cultures (OR, 9.5). Important correlations were found between bronchopulmonary dysplasiaE. cloacae (OR, 4.3); intrauterine inflammation and K. pneumoniae (OR, 3.4); and asphyxia with coagulase-negative staphylococci (OR, 3.0).

The authors concluded, “It cannot be ruled out that the positive microbiologicaresults of blood, anal and pharyngeal cultures may become prognostic markers for the early development of ROP, which would enable early initiation of ophthalmologic treatment in premature infants from the very-low-birthweight group.”

Reference

1. Modrzejewska M, Bosy-Gasior W, Grzesiak W. Association of positive bacterial cultures obtained from the throat, anus, ear, bronchi and blood in very-low-birth-weight premature infants with severe retinopathy of prematurity—own observations. J Clin Med. 2023;12:6374; https://doi.org/10.3390/jcm12196374