Association Between Rectal Colonization of Acinetobacter baumannii and Subsequent Invasive Infections in a Neonatal Intensive Care Unit

Öz

Objective: Acinetobacter spp. is a significant nosocomial pathogen in neonatal intensive care units due to its environmental persistence and multidrug resistance profile. Rectal colonization in neonates may precede invasive infections such as bloodstream infection and ventilator-associated pneumonia, serving as a potential marker for subsequent clinical deterioration. However, the factors associated with progression from rectal colonization to systemic infection in this vulnerable population remain insufficiently defined.

Materials and Methods: This retrospective cohort study was conducted between January 2018 and January 2023. Neonates with rectal Acinetobacter spp. colonization detected by surveillance cultures were included. Patients were classified according to the development of culture-confirmed bloodstream infection (BSI) and/or ventilator-associated pneumonia (VAP) during follow-up. The primary outcome was the development of invasive Acinetobacter infection after rectal colonization, and its association with recurrent colonization episodes was evaluated.

Results: A total of 73 neonates with rectal Acinetobacter spp. colonization were included. During follow-up, 10 patients (13.7%) developed BSI and 5 (6.8%) developed VAP caused by Acinetobacter spp. Birth weight, gestational age, prematurity, central venous catheter use, and duration of respiratory support were comparable between groups (all p > 0.05). However, neonates who developed invasive infection had a significantly higher number of positive rectal surveillance cultures. The overall in-hospital mortality rate was 16.4%, with a higher but not statistically significant mortality observed in patients with invasive infection (30% vs. 14%, p = 0.14).

Conclusion: Among neonates with rectal Acinetobacter spp. colonization, recurrent positivity in surveillance cultures appears to be associated with an increased risk of subsequent invasive infection, suggesting that persistence of colonization may serve as a practical clinical marker to identify high-risk patients who require intensified monitoring and infection control measures.

Anahtar Kelimeler

• Neonate
• Bloodstream infection
• Ventilator associated pneumonia
• Rectal swab
• Acinetobacter spp.

Rektal Acinetobacter baumannii Kolonizasyonu ile Yenidoğan Yoğun Bakım Ünitesinde İnvaziv Enfeksiyon Arasındaki İlişkinin Değerlendirilmesi

Öz

Amaç: Acinetobacter spp., çevresel dirençliliği ve çoklu ilaç direnci profili nedeniyle yenidoğan yoğun bakım ünitelerinde önemli bir nozokomiyal patojendir. Yenidoğanlarda rektal kolonizasyon, kan dolaşımı enfeksiyonu ve ventilatör ilişkili pnömoni gibi invaziv enfeksiyonlardan önce görülebilir ve klinik kötüleşmenin potansiyel bir belirteci olabilir. Ancak bu hassas popülasyonda rektal kolonizasyondan sistemik enfeksiyona progresyonla ilişkili faktörler yeterince tanımlanmamıştır.
Gereç ve Yöntem: Bu retrospektif kohort çalışma Ocak 2018 – Ocak 2023 tarihleri arasında yürütüldü. Sürveyans kültürlerinde rektal Acinetobacter spp. kolonizasyonu saptanan yenidoğanlar çalışmaya dahil edildi. Hastalar takip sürecinde kültürle doğrulanmış kan dolaşımı enfeksiyonu (KDE) ve/veya ventilatör ilişkili pnömoni (VİP) gelişimine göre sınıflandırıldı. Birincil sonlanım noktası, rektal kolonizasyon sonrası invaziv Acinetobacter enfeksiyonu gelişimiydi ve bunun tekrarlayan kolonizasyon atakları ile ilişkisi değerlendirildi.
Bulgular: Rektal Acinetobacter spp. kolonizasyonu olan toplam 73 yenidoğan çalışmaya dahil edildi. İzlem süresince 10 hastada (%13,7) Acinetobacter kaynaklı KDE, 5 hastada (%6,8) ise VİP gelişti. Doğum ağırlığı, gebelik haftası, prematürite, santral venöz kateter kullanımı ve solunum desteği süresi açısından gruplar arasında anlamlı fark saptanmadı (tüm p > 0,05). Ancak invaziv enfeksiyon gelişen yenidoğanlarda pozitif rektal sürveyans kültürü sayısı anlamlı olarak daha yüksekti. Genel hastane içi mortalite oranı %16,4 olup, invaziv enfeksiyon gelişen hastalarda mortalite daha yüksek olmakla birlikte istatistiksel olarak anlamlı değildi (%30’a karşı %14, p = 0,14).

Sonuç: Rektal Acinetobacter spp. kolonizasyonu olan yenidoğanlarda sürveyans kültürlerinde tekrarlayan pozitiflik, sonraki invaziv enfeksiyon gelişme riski ile ilişkili görünmektedir. Kolonizasyonun persistan seyri, yoğun izlem ve enfeksiyon kontrol önlemlerinin artırılması gereken yüksek riskli hastaların belirlenmesinde pratik bir klinik belirteç olabilir.

Anahtar Kelimeler

• Yenidoğan
• kan dolaşımı enfeksiyonu
• ventilatör ilişkili pnömoni
• rektal sürüntü
• Acinetobacter spp.

Kaynakça

1. Pillay K, Ray-Chaudhuri A, O'Brien S, Heath P, Sharland M. Acinetobacter spp. in neonatal sepsis: an urgent global threat. Front Antibiot. 2024;3:1448071. Published 2024 Sep 3. doi:10.3389/frabi.2024.1448071
2. World Health Organization. Global priority list of antibiotic-resistant bacteria to guide research, discovery and development of new antibiotics. Geneva: World Health Organization; 2024. Available from: https://iris.who.int/handle/10665/XXXXXX
3. Arhoune B, Oumokhtar B, Hmami F, et al. Intestinal carriage of antibiotic resistant Acinetobacter baumannii among newborns hospitalized in Moroccan neonatal intensive care unit. PLoS One. 2019;14(1):e0209425. Published 2019 Jan 10. doi:10.1371/journal.pone.0209425
4. Folgori L, Tersigni C, Hsia Y, et al. The relationship between Gram-negative colonization and bloodstream infections in neonates: a systematic review and meta-analysis. Clin Microbiol Infect. 2018;24(3):251-257. doi:10.1016/j.cmi.2017.08.008
5. Khurana S, Kaur H, Biswal M, Saini SS, Ray P. Association Between Rectal Colonization and Risk of Blood Stream Infection with Acinetobacter Baumannii in Neonates. Ann Pediatr. 2021; 4(1): 1075.
6. Ferreira ICDS, Menezes RP, Jesus TA, et al. Impact of intestinal colonization by Gram-negative bacteria on the incidence of bloodstream infections and lethality in critically ill neonates. J Infect Public Health. 2023;16 Suppl 1:9-18. doi:10.1016/j.jiph.2023.10.040
7. Gramatniece A, Silamikelis I, Zahare I, et al. Control of Acinetobacter baumannii outbreak in the neonatal intensive care unit in Latvia: whole-genome sequencing powered investigation and closure of the ward. Antimicrob Resist Infect Control. 2019;8:84. Published 2019 May 22. doi:10.1186/s13756-019-0537-z
8. Medina-Presentado JC, Seija V, Vignoli R, et al. Polyclonal endemicity of Acinetobacter baumannii in ventilated patients in an intensive care unit in Uruguay. Int J Infect Dis. 2013;17(6):e422-e427. doi:10.1016/j.ijid.2012.12.025

9. European Committee on Antimicrobial Susceptibility Testing. Breakpoint tables for interpretation of MICs and zone diameters, version 13.0. EUCAST; 2023. Available from: https://www.eucast.org/clinical_breakpoints/
10. Parm Ü, Metsvaht T, Sepp E, et al. Mucosal surveillance cultures in predicting Gram-negative late-onset sepsis in neonatal intensive care units. J Hosp Infect. 2011;78(4):327-332. doi:10.1016/j.jhin.2011.03.025
11. Playford EG, Craig JC, Iredell JR. Carbapenem-resistant Acinetobacter baumannii in intensive care unit patients: risk factors for acquisition, infection and their consequences. J Hosp Infect. 2007;65(3):204-211. doi:10.1016/j.jhin.2006.11.010
12. R. Tekin, İ. Yolbaş, F. Bozkurt, et al. Risk Factors for Extensively Drug-Resistant Acinetobacter baumannii in Neonatal Patients. J Pediatr Infect Dis 2021; 16(01): 031-035.
13. Roberts T, Limmathurotsakul D, Turner P, Day NPJ, Vandepitte WP,Cooper BS. Antimicrobial-resistant Gram-negative colonization ininfants from a neonatal intensive care unit in Thailand. J Hosp Infect. 2019;103(2):151-5.
14. Çetin B, Tekin S, Güneş T. Evaluation of Acinetobacter baumannii Infections and Skin Colonization in the Neonatal Intensive Care Unit Yenidoğan Yoğun Bakım Ünitesinde Acinetobacter baumannii Enfeksiyonları ve Cilt Kolonizasyonunun Değerlendirilmesi. Cocuk Enfeksiyon Dergisi, 2022, 16.3.
15. Garrouste-Orgeas M, Chevret S, Arlet G, et al. Oropharyngeal or gastric colonization and nosocomial pneumonia in adult intensive care unit patients. A prospective study based on genomic DNA analysis. Am J Respir Crit Care Med. 1997;156(5):1647-1655. doi:10.1164/ajrccm.156.5.96-04076
16. Tacconelli E, Carrara E, Savoldi A, et al. Discovery, research, and development of new antibiotics: the WHO priority list of antibiotic-resistant bacteria and tuberculosis. Lancet Infect Dis. 2018;18(3):318-327. doi:10.1016/S1473-3099(17)30753-3
17. Karampatakis T, Tsergouli K, Iosifidis E, et al. Effects of an Active Surveillance Program and Enhanced Infection Control Measures on Carbapenem-Resistant Gram-Negative Bacterial Carriage and Infections in Pediatric Intensive Care. Microb Drug Resist. 2019;25(9):1347-1356. doi:10.1089/mdr.2019.0061
18. Harris AD, Johnson JK, Pineles L, O'Hara LM, Bonomo RA, Thom KA. Patient-to-Patient Transmission of Acinetobacter baumannii Gastrointestinal Colonization in the Intensive Care Unit. Antimicrob Agents Chemother. 2019;63(8):e00392-19. Published 2019 Jul 25. doi:10.1128/AAC.00392-19
19. Huertas Vaquero M, Asencio Egea MA, Carranza González R, et al. Association between antibiotic pressure and the risk of colonization/infection by multidrug-resistant Acinetobacter baumannii complex: a time series analysis. Rev Esp Quimioter. 2021;34(6):623-630. doi:10.37201/req/061.2021