The Roles of a Multidrug-Resistant Klebsiella pneumoniae High-Risk Clone and Its Resistance Plasmids on the Gastrointestinal Colonization and Host-Defense Effectors in the Gut

• Published in: Antibiotics (Basel) Vol. 13; no. 8; p. 698
• Main Authors: Stercz, Balazs, Domokos, Judit, Dunai, Zsuzsanna A, Makra, Nora, Juhasz, Janos, Ostorhazi, Eszter, Kocsis, Bela, Szabo, Dora
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 26-07-2024; MDPI
• Subjects: Antibiotics; Bacteria; Cloning; Colonization; Correlation; Defensins; Development and progression; Digestive system; Drug resistance in microorganisms; E coli; Feces; Gastrointestinal system; Gastrointestinal tract; Genes; Genetic aspects; gut; Health aspects; Health care; Hospitals; Immunoglobulin A; Infections; Intestinal microflora; Klebsiella; Klebsiella infections; Klebsiella pneumoniae; Lachnospiraceae; microbiome; Microbiota; Microorganisms; mouse model; Multidrug resistance; Multidrug resistant organisms; Muribaculaceae; Pathogens; Physiological aspects; Plasmids; rRNA 16S; Hungary; Europe; CTX-M; OXA-carbapenemase; multidrug resistance; defensins; mouse model; colonization; gut; ESBL; microbiome
• ISSN: 2079-6382; 2079-6382
• DOI: 10.3390/antibiotics13080698

The asymptomatic gastrointestinal colonization of multidrug-resistant (MDR) bacteria can lead to difficult-to-treat infections. We investigated the role of host factors influencing colonization in an orogastrical murine infection model using a CTX-M-15- and OXA-162-producing
ST15 (MDR-KP) strain, as well as
J53 (EC) and
transconjugants with an IncFII(K) plasmid carrying CTX-M-15 (EC-CTXM), and with an IncL plasmid carrying OXA-162 (EC-OXA) genes. The fecal bacterial count in colony-forming unit/gram stool (CFU/g) was determined by cultivation, IgA and defensin levels by ELISA, and gut microbiota by 16S rRNA analysis. The CFU was the lowest in EC, followed by EC-OXA and EC-CTXM, and the highest in the MDR-KP group. The IgA level in feces increased in MDR-KP, EC-CTXM, and EC-OXA, and did not change in EC. The beta-defensin 3 level markedly increased in all groups, with the highest values in MDR-KP and EC-CTXM. Alpha-defensin-5 increased in all groups especially in EC. In microbiota, the
phylum was dominant in MDR-KP, EC-CTXM, and EC-OXA, whereas
was dominant in EC. The
family was significantly more common in the MDR-KP and EC-OXA groups, while the
family was dominant in the EC group. While fecal IgA levels positively correlated with colonizing bacterial CFU, the alpha-defensin 5 levels inversely correlated with CFUs and IgA levels. The presence of the IncFII(K) plasmid induced beta-defensin 3 production. The amounts of the
family members exhibited a correlation with the IncL plasmid. The detected amounts of the
family indicated the protective role against the high-risk clone and the resistance plasmids' dissemination. Our results suggest that not only the MDR-KP clone itself but also the resistance plasmids play a primary role in the colonization rate in the gastrointestinal tract. Both the MDR-KP clone as well as the IncFII(K) and IncL resistance plasmids provide survival and colonization benefits in the gut.