ST37 Klebsiella Pneumoniae : Development of Carbapenem Resistance in Vivo During Antimicrobial Therapy in Neonates

Abstract

Aim:To investigate the mechanism leading to in vivo carbapenem resistance development in Klebsiella pneumoniae. Methods: Carbapenemase was detected using the modified carbapenem inactivation method. β-lactamases resistant genes were identified by PCR and sequencing. Clonal relatedness was evaluated by random amplified polymorphic DNA and multiple locus sequence typing. The relationship between sequence typing and resistant genes was analyzed by using the chi-squared test. Results: All ST37 carbapenem-resistant isolates were bla OXA-1 positive and all ST37 carbapenem-sensitive isolates were bla OXA-1 negative at Stage I. A significant relationship between carbapenem resistance and bla OXA-1 was observed. The bla OXA-1 -positive rate was significantly higher in ST37 K. pneumoniae than others. Conclusion: This is the first study about the development of carbapenem resistance in vivo potentially mediated by bla OXA-1 in ST37 K. pneumoniae among neonates.

Homology analysis between clinically isolated extraintestinal and enteral Klebsiella pneumoniae among Neonates

“…Excluding the completely concordant strains, the analysis of the homology among ST37 and ST1083 should be con rmed. According to the analyses, ST37 and ST1083 were in the same cluster (two alleles of the 7 housekeeping genes differed), concluding that the two were closely related and the results validated a great deal of our previous research [19]. And our data indicated that ST37 were the main epidemic clones in the Neonate Ward, which showed consistency with what found in other studies [19,38].…”

“…According to the analyses, ST37 and ST1083 were in the same cluster (two alleles of the 7 housekeeping genes differed), concluding that the two were closely related and the results validated a great deal of our previous research [19]. And our data indicated that ST37 were the main epidemic clones in the Neonate Ward, which showed consistency with what found in other studies [19,38]. It was discovered that ST37 are presumably to be a potential high-risk MDR K.pneumoniae clonal lineage [39].Furthermore, it is reported that carriage of carbapenem-resistant K. pneumoniae (CRKP) in the GI tract may precede and possibly serve as a source for subsequent clinical infections in approximately 9% of carriers [40,41].…”

“…The tree shows that ST37 and ST1083 were related. In our previous study, ST37 and ST1083 belong to the same clone complex CC37 [19].…”

“…The concatenated sequences of all seven loci were used to draw a phylogenetic tree. The results showed that ST37 and ST1083 were homologous, which belong to CC37 clone complex [19]. Complete results were shown in Figure 1.…”

Prevalence of pks gene cluster and characteristics of Klebsiella pneumoniae‐induced bloodstream infections

“…This circumstance was possibly owing to the fact that pks + isolates possessed high percentages of hypervirulent serotypes and virulence genes as the acquisition of virulence is usually accompanied by reduced drug resistance. Currently, the emergence of multidrug‐, extremely drug‐, or pan‐drug‐resistant cKP has already become a tough situation in clinical studies . Nonetheless, multidrug‐resistant hvKP strains producing extended spectrum β‐lactamase (ESBL) or carbapenemase have also been described .…”