bioRxiv ScienceSearch

bioRxiv · 10.1101/523167

Inhibition of MreB and ftsZ proteins to minimize E. coli biofilm formation

Abstract

In the United States, more than two million individuals become infected by antibiotic-resistant bacteria, resulting in over 23,000 deaths annually. Bacterial biofilms, one of the major causes of this resistance, form a complex extracellular matrix that physically block antibiotic treatment. Within planktonic bacteria, two proteins, MreB and ftsZ, play a key role in bacterial cell growth and development. MreB regulates this development through maintaining the rod-like shape of gram-negative bacteria, while ftsZ regulates the timing and location of cell division. The present study compared the effects of two protein-inhibitors on biofilm formation of E. coli; the inhibitors, A22 Hydrochloride and PC190723, inhibit MreB (cell shape) and ftsZ (cell division), respectively. Efficacy was measured with a crystal violet staining assay. Four experiments were designed testing 1) the minimum inhibitory concentration of the inhibitors, 2) the synergistic effect of the inhibitors, 3) the microscopic effects of the inhibitors, and 4) the effect of the inhibitors on antibiotic susceptibility. A mid-level dosage of A22 significantly decreased biofilm density while there was no response to PC190732. The effect of A22 was verified microscopically, observing the change from bacilli cells to coccoid ones via the inhibition of MreB. In the second experiment, with conjunct inhibition, no interaction was found. Lastly, A22 was as effective as Amoxicillin in disrupting biofilms. The inhibition of MreB was found to have a key role in biofilm development. A model is proposed for biofilm density based on cell shape as affected by MreB.\n\nImportanceEach year, more than 2 million Americans acquire antibiotic-resistant infection and 23,000 of them die (CDC, 2013). In a study done by Barsoumian et. al (2015), there was a 16% mortality rate pertaining to biofilm-related infections while non-biofilm infection caused a 5% mortality rate. These casualties arent limited to the United States. Abroad, antibiotic resistance is a huge issue: 25,000 deaths estimated in the EU; 38,000 deaths in Thailand; and 58,000 deaths in India, among infants alone (CDC, 2012). It is these statistics that inform us that antibiotic resistance must be addressed.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Charles, E.. 2019-01-17. Inhibition of MreB and ftsZ proteins to minimize E. coli biofilm formation. https://doi.org/10.1101/523167

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A conserved cysteine-histidine-glutamate metal site identifies DUF501 (Rv1025), an essential uncharacterised protein family of Mycobacterium tuberculosis, as a candidate metalloenzyme and drug target

A substantial fraction of the Mycobacterium tuberculosis proteome remains functionally uncharacterised. Rv1025, a 155-residue protein carrying the domain of unknown function DUF501 (Pfam PF04417), is essential by transposon mutagenesis and vulnerable by CRISPR interference, an attractive but neglected drug target, yet has never been functionally described. The family (4,370 proteins, no Gene Ontology term, no solved structure) is uncharacterised across all organisms and essential in three Actinobacterial genera. A Foldseek search of the AlphaFold model against complete structural databases finds no significant homolog, indicating a novel fold. The operon eno-divIC-Rv1025-ppx2 is conserved across the Actinobacteria phylum, yet AlphaFold-Multimer finds no direct complex between Rv1025 and its neighbour DivIC. Instead, conservation across 8,700 homologous sequences reveals a near-invariant Cys113-His115-Glu59 cluster forming a pocket. Holo AlphaFold3 predictions with Zn, Fe and Mn confidently place a divalent metal on this triad at 2.25-2.47 A; mutating the triad relocates the metal, and an independent backbone-geometry predictor recovers the same site, confirming specificity. The triad is universal across the family: present in all 1,472 near-complete bacterial sequences of the Pfam alignment, with no non-conservative substitution among the 2,228 sequences examined, a defining feature of bacterial DUF501 rather than a mycobacterial peculiarity. We propose that DUF501 is a metal-binding protein and candidate metalloenzyme, the first functional hypothesis for this family, whose conserved, essential metal pocket is a promising drug target. As the predictions build on a conservation-defined site within a fully computational study, they are supportive rather than proof of metal occupancy and warrant experimental validation.

microbiology

Mycoplasmal endosymbionts of Trichomonas vaginalis are associated with reduced risk for Chlamydia trachomatis endometrial infection in asymptomatic, coinfected, women.

Trichomonas vaginalis is a protozoan parasite that causes trichomoniasis, the most common curable non-viral sexually transmitted infection, and Chlamydia trachomatis is a bacterial pathogen that can ascend to the upper genital tract and cause pelvic inflammatory disease, infertility, and ectopic pregnancy. T. vaginalis harbors bacterial endosymbionts, including Candidatus Malacoplasma girerdii, an obligate symbiont, and Metamycoplasma hominis, which can live freely or symbiotically. In a 16S rRNA sequencing study of the cervicovaginal microbiome of women at high risk for chlamydial infection, Ca. M. girerdii abundance was one of 13 features predicting lack of chlamydial spread to the endometrium, despite no direct association between T. vaginalis infection and reduced chlamydial ascension. Investigating the relationship between these microorganisms further, we found that T. vaginalis vaginal abundance correlated positively with chlamydial burden in women whose infection was confined to the cervix, while a nonsignificant inverse relationship was seen in women with endometrial spread. Among participants with high chlamydial burden, Ca. M. girerdii was detected exclusively in women without endometrial infection. Both endosymbionts trended toward more frequent detection, and higher abundance, in coinfected women without endometrial spread, while M. hominis abundance correlated strongly with T. vaginalis burden in this group. These findings suggest that mycoplasmal endosymbionts of T. vaginalis, rather than T. vaginalis itself, are microbial factors limiting chlamydial ascension, and point to a three-way interaction between parasite, endosymbiont, and bacterial pathogen that shapes upper genital tract C. trachomatis infection risk.

microbiology

Understanding the physiological alterations of Vibrio cholerae upon exposure to L-ascorbic acid

The scourge of cholera remains a major global public health threat. It affects up to 4 million people worldwide and causes tens of thousands of deaths each year. The disease is experiencing a concerning resurgence in many parts of Africa, the Middle East, and Asia. To effectively tackle cholera and circumvent rising antimicrobial resistance, targeted biological and preventive approaches, complementing traditional rehydration, are urgently needed. In this regard, our group has demonstrated the efficacy of L-ascorbic acid in controlling the growth and pathogenesis of Vibrio cholerae in vitro. The present work further provides a mechanistic elucidation of the L-ascorbic acid-mediated physiological changes in V. cholerae and also bolsters such a non-antibiotic approach to control cholera.

microbiology