Distribution of virulence genes and antimicrobial resistance of isolated from hospitalized neonates: A multi-center study across China.

BACKGROUND

is the most common gram-negative pathogen to cause neonatal infections. Contemporary virulence characterization and antimicrobial resistance (AMR) data of neonatal isolates in China are limited.

METHODS

A total of 159  strains isolated from neonates were collected and classified into invasive and non-invasive infection groups, according to their site of origin. The presence of virulence genes was determined using polymerase chain reaction (PCR). All the strains were subjected to antimicrobial susceptibility testing using the broth dilution method.

RESULTS

The top three virulence genes with the highest detection rates were (90.6 %), (88.7 %), and II (88.1 %). The prevalences of ( = 0.023), K1 ( = 0.019), ( < 0.001), and ( = 0.027) were significantly higher in the invasive infection group than in the non-invasive infection group. Resistance to ceftazixime, sulfamethoxazole/trimethoprim, and ciprofloxacin was 75.5 %, 65.4 %, and 48.4 %, respectively. Lower rates of resistance to ceftazidime ( = 0.022), cefepime ( = 0.005), ticarcillin/clavulanic acid ( = 0.020) and aztreonam ( = 0.001) were observed in the invasive infection group compared to the non-invasive infection group. The number of virulence genes carried by was positively correlated with the number of antibiotics to which the isolates were resistant ( = 0.71,  = 0.016), and a specific virulence gene was associated with resistance to various species of antibiotics.

CONCLUSIONS

Neonatal isolates carried multiple virulence genes and were highly resistant to antibiotics. Further studies are needed to understand the molecular mechanisms underlying the association between virulence and AMR.