Emergence of multidrug-resistant Staphylococcus haemolyticus in neonatal intensive care unit in Southern France, a genomic study

• Published in: Emerging microbes & infections Vol. 13; no. 1; p. 2353291
• Main Authors: Magnan, Chloé, Morsli, Madjid, Salipante, Florian, Thiry, Blandine, Attar, Julie El, Maio, Massimo Di, Safaria, Maryam, Tran, Tu-Anh, Dunyach-Remy, Catherine, Ory, Jérôme, Richaud-Morel, Brigitte, Sotto, Albert, Pantel, Alix, Lavigne, Jean-Philippe
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01-12-2024; Taylor & Francis Group
• Subjects: Anti-Bacterial Agents - pharmacology; Case-Control Studies; Cross Infection - epidemiology; Cross Infection - microbiology; Drug Resistance, Multiple, Bacterial - genetics; emergence; Female; France - epidemiology; Genome, Bacterial; Genotype; Humans; Infant, Newborn; Intensive Care Units, Neonatal; Male; Microbial Sensitivity Tests; multidrug resistance; neonatal intensive care unit; Risk Factors; ST29; Staphylococcal Infections - epidemiology; Staphylococcal Infections - microbiology; Staphylococcus haemolyticus; Staphylococcus haemolyticus - classification; Staphylococcus haemolyticus - drug effects; Staphylococcus haemolyticus - genetics; Staphylococcus haemolyticus - isolation & purification; Whole Genome Sequencing; France; multidrug resistance; Staphylococcus haemolyticus; emergence; neonatal intensive care unit; whole-genome sequencing; antiseptic resistance; healthcare associated infections; ST29
• ISSN: 2222-1751; 2222-1751
• DOI: 10.1080/22221751.2024.2353291

An emergence of multidrug-resistant (MDR)
has been observed in the neonatal intensive care unit (NICU) of Nîmes University Hospital in southern France. A case-control analysis was conducted on 96 neonates, to identify risk factors associated with
infection, focusing on clinical outcomes. Forty-eight MDR
strains, isolated from neonates between October 2019 and July 2022, were investigated using routine
procedures and whole-genome sequencing. Additionally, five
isolates from adult patients were sequenced to identify clusters circulating within the hospital environment. The incidence of neonatal
was significantly associated with low birth weight, lower gestational age, and central catheter use (
< 0.001). Sepsis was the most frequent clinical manifestation in this series (20/46, 43.5%) and was associated with five deaths. Based on whole-genome analysis, three
genotypes were predicted: ST1 (6/53, 11%), ST25 (3/53, 5.7%), and ST29 (44/53, 83%), which included the subcluster II-A, predominantly emerging in the neonatal department. All strains were profiled
to be resistant to methicillin, erythromycin, aminoglycosides, and fluoroquinolones, consistent with
antibiotic susceptibility tests. Moreover,
prediction of biofilm formation and virulence-encoding genes supported the association of ST29 with severe clinical outcomes, while the persistence in the NICU could be explained by the presence of antiseptic and heavy metal resistance-encoding genes. The clonality of
ST29 subcluster II-A isolates confirms healthcare transmission causing severe infections. Based on these results, reinforced hygiene measures are necessary to eradicate the nosocomial transmission of MDR strains.