Livestock associated Staphylococcus aureus in cystic fibrosis patients in Spain: Detection of MRSA and MSSA CC398

• Published in: Microbial pathogenesis Vol. 197; p. 107016
• Main Authors: Eguizábal, Paula, López-Calleja, Ana Isabel, Arias, Antonina, Antoñanzas-Torres, Irene, Campaña-Burguet, Allelen, González-Azcona, Carmen, Martínez, Agustí, Martin-de Vicente, Carlos, Herrero, Inés, Rezusta, Antonio, Torres, Carmen, Lozano, Carmen
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-12-2024
• Subjects: Cystic fibrosis; MRSA-CC398; Small colony variants; Staphylococcus aureus; Cystic fibrosis; MRSA-CC398; Small colony variants; Staphylococcus aureus; small colony variants; cystic fibrosis
• ISSN: 0882-4010; 1096-1208; 1096-1208
• DOI: 10.1016/j.micpath.2024.107016

Staphylococcus aureus is one of the most prevalent pathogens in cystic fibrosis (CF), being of special relevance those methicillin-resistant (MRSA). The livestock-associated (LA)-MRSA lineage CC398 is an emerging problem, specially related to pig-farming (PF) environments. The objective was to characterize the S. aureus isolates recovered from CF-patients in a Spanish hospital located in a region with high-PF activity.
Forty-two isolates were obtained (January–October/2022) and characterised (one/patient). The antimicrobial resistance phenotype/genotype was evaluated by Microscan/PCR. The presence of virulence and Immune Evasion Cluster (IEC) genes as well as the agr type was determined by PCR. MLST and spa-typing were studied by PCR-sequencing.
Nine of the 42 isolates were MRSA (21.4 %), and 8 of them multidrug resistant (MDR). Among MRSA, 6 spa-types were detected, assigned to CC1, CC5, CC8, CC30, and CC398. Four MRSA isolates belonged to the lineage CC398-t011-IEC negative (animal adapted-clade, LA-MRSA). The remaining 33 isolates were methicillin-susceptible (MSSA), of 26 spa-types and associated with 11 CCs (predominant: CC5, CC30, and CC398). Seven MSSA isolates were of the lineage CC398 (spa-types t034, t108, t571, t20352); four of them were IEC-positive and erm(T)-positive (t571, and t20352, human-adapted CC398 clade), being IEC-negative the remaining three. The tst and eta/etb genes were identified in 12 and 2 isolates, respectively (none CC398). Small-colony-variants were demonstrated in 9 isolates (two CC398, both MDR).
The lineage CC398 was very frequent among CF-patients (26.2 %), both among MSSA and MRSA. The emergence of LA-MRSA-CC398 in CF-patients requires monitorization, especially in hospitals of high-PF-regions.
•Detection of CC398 in a Spanish hospital located in a high-pig-farming-region.•High frequency of detection of MRSA- and MSSA-CC398 isolates among CF-patients.•The emergence of LA-MRSA isolates in CF-patients requires monitorization.