Beta-lactam induced morphological changes in serum of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae blood isolates

Opstrup, Katharina V; Christiansen, Gunna; Birkelund, Svend

doi:10.1016/j.micinf.2022.105036

Cited by 7 publications

(19 citation statements)

References 42 publications

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“…These PBPs, which play a role in completing peptidoglycan assembly, are also involved in cell division and elongation. Binding of meropenem to these PBPs can lead to the morphology of bacterial cells to become round or oval, with a wider centre (Opstrup et al 2023 ). In this study, we believe that the induction of round cell morphology by meropenem in R. ornithinolytica and K. quasivariicola and comma-shaped cell morphology in P. agglomerans may be due to binding to different combinations of PBPs.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of the in vitro effects of concentrations of antibiotics on three Enterobacteriaceae isolates

Delik,

Eroğlu,

Tefon-Öztürk

2024

World J Microbiol Biotechnol

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Due to the misuse and overuse of antibiotics, bacteria are now exposed to sub-minimum inhibitory concentrations (sub-MICs) of antibiotics in various environments. In recent years, exposure of bacteria to sub-MICs of antibiotics has led to the widespread emergence of antibiotic-resistant bacteria. In this study, three bacterial species from the Enterobacteriaceae family (Raoultella ornithinolytica, Pantoea agglomerans and Klebsiella quasivariicola) were isolated from water. The antibiotic susceptibility of these bacteria to 16 antibiotics was then investigated. The effects of sub-MICs of four selected antibiotics (kanamycin, chloramphenicol, meropenem, and ciprofloxacin) on the growth, biofilm formation, surface polysaccharide production, siderophore production, morphology, and expression of the translational/transcriptional regulatory transformer gene rfaH of these bacteria were analysed. The MICs of kanamycin, chloramphenicol, meropenem, and ciprofloxacin were determined to be 1, 2, 0.03 and 0.03 µg/mL for R. ornithinolytica; 0.6, 6, 0.03 and 0.05 µg/mL for P. agglomerans; and 2, 5, 0.04 and 0.2 µg/mL for K. quasivariicola. The growth kinetics and biofilm formation ability decreased for all three isolates at sub-MICs. The surface polysaccharides of R. ornithinolytica and P. agglomerans increased at sub-MICs. There was no significant change in the siderophore activities of the bacterial isolates, with the exception of MIC/2 meropenem in R. ornithinolytica and MIC/2 kanamycin in K. quasivariicola. It was observed that the sub-MICs of meropenem and ciprofloxacin caused significant changes in bacterial morphology. In addition, the expression of rfaH in R. ornithinolytica and K. quasivariicola increased with the sub-MICs of the selected antibiotics.

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Section: Discussionmentioning

confidence: 99%

Evaluation of the in vitro effects of concentrations of antibiotics on three Enterobacteriaceae isolates

Delik,

Eroğlu,

Tefon-Öztürk

2024

World J Microbiol Biotechnol

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“…API 20E and 16S rRNA gene analyses were used to determine the species of BPM. The BPM and BtE264 strains were cultured on sheep blood agar incubated at 37 °C for 18 h, stained with crystal violet, iodine solution, 95 % alcohol and safranine in accordance with standard protocols and examined through light microscopy [10]. All the isolates were transferred to LB broth medium and grown in a shaking incubator at 180 r.p.m.…”

Section: Methodsmentioning

confidence: 99%

Genomic features and virulence characteristics of a rare Burkholderia thailandensis strain causing human infection

et al. 2023

Journal of Medical Microbiology

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Introduction. Burkholderia thailandensis is a clinically rare opportunistic pathogen in the genus Burkholderia , and the genomic features and virulence characteristics of B. thailandensis strains that cause human infection remain unclear. Gap Statement. B. thailandensis strains with different virulence induce different host innate immune responses in vitro. Aim. This work aimed to understand the sequence diversity, phylogenetic relationship, and virulence of B. thailandensis BPM causing human infection. Methodology. The comparative molecular and genomic analyses, and mouse infection studies were applied to analyse the virulence and genomic features of B. thailandensis BPM originating from China. Results. The whole genome sequence analysis showed that the genomes of BPM and other avirulent B. thailandensis strains were broadly similar, comprising two highly syntenic chromosomes with comparable numbers of coding regions (CDs), protein family distributions, and horizontally acquired genomic islands. By examining species-specific genomic regions, we obtained molecular explanations for previously known differences in virulence and discovered the potential specific virulence-associated genes of BPM, which likely work together to confer the virulence of BPM. Significantly reduced LD50 and survival rates during mouse infection experiments were found in BPM compared to the avirulent B. thailandensis E264 (BtE264). Conclusion. Taken together, the results of this study provide basic information on the genomic features and virulence characteristics of the virulent B. thailandensis strain BPM, which is helpful for understanding its evolution as it relates to pathogenesis and environmental adaptability.

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“…Two major OMPs in K. pneumoniae, OmpK35 and OmpK36, are co-regulated porins responsible of nonspecific influx of nutrients, but also other hydrophilic molecules such as beta-lactam antibiotics [59]. Loss of OmpK porins has been correlated to an increase in resistance against beta-lactam antibiotics, and in some cases, a decrease in virulence [4,60,61]. Complement activation by OmpK has been demonstrated via C1q binding [62].…”

Section: Outer Membrane Proteinsmentioning

confidence: 99%

“…K. pneumoniae infections are becoming increasingly difficult to treat, as resistance against the most used and effective antibiotics steadily rises [72]. The selective pressure resulting from the extensive use of antibiotics has generated multi-drug and pan-resistant isolates, and horizontal gene transfer trough mobile genetic elements has been a pivotal factor for the rapid dissemination of resistance genes within the Enterobacteriaceae [4,73,74]. Multidrug-resistant isolates are resistant to at least one agent in three different classes of antibiotics, limiting the treatment options to very few drugs [4,75].…”

Section: Antimicrobial Drug Resistancementioning

confidence: 99%

“…K. pneumoniae is a Gram-negative, facultative anaerobe, rod-shaped, non-motile member of the family Enterobacteriaceae measuring approximately 1 x 1,5-3 µm. It exists ubiquitously in nature [3][4][5]. It is a common inhabitant of the gastrointestinal tract of humans and animals, and colonizes most mucosal surfaces [2,5].…”

Section: Introduction 1 Klebsiella Pneumoniaementioning

confidence: 99%

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Serum and antibiotic resistance of Klebsiella pneumoniae blood isolates

Opstrup¹

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Beta-lactam induced morphological changes in serum of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae blood isolates

Cited by 7 publications

References 42 publications

Evaluation of the in vitro effects of concentrations of antibiotics on three Enterobacteriaceae isolates

Evaluation of the in vitro effects of concentrations of antibiotics on three Enterobacteriaceae isolates

Genomic features and virulence characteristics of a rare Burkholderia thailandensis strain causing human infection

Serum and antibiotic resistance of Klebsiella pneumoniae blood isolates

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