A host-directed macrocyclic peptide therapeutic for MDR gram negative bacterial infections

AbstractThe emergence of infections by carbapenem resistant Enterobacteriaceae (CRE) pathogens has created an urgent public health threat, as carbapenems are among the drugs of last resort for infections caused by a growing fraction of multi-drug resistant (MDR) bacteria. There is global consensus that new preventive and therapeutic strategies are urgently needed to combat the growing problem of MDR bacterial infections. Here, we report on the efficacy of a novel macrocyclic peptide, minimized theta-defensin (MTD)-12813 in CRE sepsis. MTD12813 is a theta-defensin inspired cyclic peptide that is highly effective against CRE pathogens K. pneumoniae and E. coli in vivo. In mouse septicemia models, single dose administration of MTD12813 significantly enhanced survival by promoting rapid host-mediated bacterial clearance and by modulating pathologic cytokine responses, restoring immune homeostasis, and preventing lethal septic shock. The peptide lacks direct antibacterial activity in the presence of mouse serum or in peritoneal fluid, further evidence for its indirect antibacterial mode of action. MTD12813 is highly stable in biological matrices, resistant to bacterial proteases, and nontoxic to mice at dose levels 100 times the therapeutic dose level, properties which support further development of the peptide as a first in class anti-infective therapeutic.

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The antimicrobial peptide ZY4 combats multidrug-resistantPseudomonas aeruginosaandAcinetobacter baumanniiinfection

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1909585117 ◽

2019 ◽

Vol 116 (52) ◽

pp. 26516-26522 ◽

Cited By ~ 33

Author(s):

James Mwangi ◽

Yizhu Yin ◽

Gan Wang ◽

Min Yang ◽

Ya Li ◽

...

Keyword(s):

Bacterial Infections ◽

Cyclic Peptide ◽

Disulfide Bridge ◽

Multidrug Resistant ◽

Infection Model ◽

Biofilm Inhibition ◽

Carbapenem Resistant ◽

Target Organs ◽

Induce Resistance

The emergence of carbapenem-resistantAcinetobacter baumanniiandPseudomonas aeruginosaraises fears of untreatable infections and poses the greatest health threats. Antimicrobial peptides (AMPs) are regarded as the most ideal solution to this menace. In this study, a set of peptides was designed based on our previously reported peptide cathelicidin-BF-15, and the lead peptide ZY4, a cyclic peptide stabilized by a disulfide bridge with high stability in vivo (the half-life is 1.8 h), showed excellent activity againstP. aeruginosaandA. baumannii, including standard and clinical multidrug-resistant (MDR) strains. ZY4 killed bacteria by permeabilizing the bacterial membrane and showed low propensity to induce resistance, exhibited biofilm inhibition and eradication activities, and also killed persister cells. Notably, administration of ZY4 decreased susceptibility to lung infection byP. aeruginosaand suppressed dissemination ofP. aeruginosaandA. baumanniito target organs in a mouse septicemia infection model. These findings identify ZY4 as an ideal candidate against MDR bacterial infections.

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Mechanistic insights into synergy between nalidixic acid and tetracycline against clinical isolates of Acinetobacter baumannii and Escherichia coli

Communications Biology ◽

10.1038/s42003-021-02074-5 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Amit Gaurav ◽

Varsha Gupta ◽

Sandeep K. Shrivastava ◽

Ranjana Pathania

Keyword(s):

Escherichia Coli ◽

Acinetobacter Baumannii ◽

Nalidixic Acid ◽

Bacterial Infections ◽

Clinical Isolates ◽

Hospital Environment ◽

Infection Model ◽

Drug Resistant ◽

E Coli

AbstractThe increasing prevalence of antimicrobial resistance has become a global health problem. Acinetobacter baumannii is an important nosocomial pathogen due to its capacity to persist in the hospital environment. It has a high mortality rate and few treatment options. Antibiotic combinations can help to fight multi-drug resistant (MDR) bacterial infections, but they are rarely used in the clinics and mostly unexplored. The interaction between bacteriostatic and bactericidal antibiotics are mostly reported as antagonism based on the results obtained in the susceptible model laboratory strain Escherichia coli. However, in the present study, we report a synergistic interaction between nalidixic acid and tetracycline against clinical multi-drug resistant A. baumannii and E. coli. Here we provide mechanistic insight into this dichotomy. The synergistic combination was studied by checkerboard assay and time-kill curve analysis. We also elucidate the mechanism behind this synergy using several techniques such as fluorescence spectroscopy, flow cytometry, fluorescence microscopy, morphometric analysis, and real-time polymerase chain reaction. Nalidixic acid and tetracycline combination displayed synergy against most of the MDR clinical isolates of A. baumannii and E. coli but not against susceptible isolates. Finally, we demonstrate that this combination is also effective in vivo in an A. baumannii/Caenorhabditis elegans infection model (p < 0.001)

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In Vitro and In Vivo Antibacterial Activities of SM-216601, a New Broad-Spectrum Parenteral Carbapenem

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.10.4185-4196.2005 ◽

2005 ◽

Vol 49 (10) ◽

pp. 4185-4196 ◽

Cited By ~ 27

Author(s):

Yutaka Ueda ◽

Katsunori Kanazawa ◽

Ken Eguchi ◽

Koji Takemoto ◽

Yoshiro Eriguchi ◽

...

Keyword(s):

Bacterial Infections ◽

Antibacterial Activities ◽

Multiresistant Pathogens ◽

E Coli ◽

Wide Range ◽

Agar Dilution ◽

Resistant Strains ◽

Mrsa Strains

ABSTRACT SM-216601 is a novel parenteral 1β-methylcarbapenem. In agar dilution susceptibility testing, the MIC of SM-216601 for 90% of the methicillin-resistant Staphylococcus aureus (MRSA) strains tested (MIC90) was 2 μg/ml, which was comparable to those of vancomycin and linezolid. SM-216601 was also very potent against Enterococcus faecium, including vancomycin-resistant strains (MIC90 = 8 μg/ml). SM-216601 exhibited potent activity against penicillin-resistant Streptococcus pneumoniae, ampicillin-resistant Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, with MIC90s of less than 0.5 μg/ml, and intermediate activity against Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa. The therapeutic efficacy of SM-216601 against experimentally induced infections in mice caused by S. aureus, E. faecium, E. coli, and P. aeruginosa reflected its in vitro activity and plasma level. Thus, SM-216601 is a promising candidate for nosocomial bacterial infections caused by a wide range of gram-positive and gram-negative bacteria, including multiresistant pathogens.

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Comparison of Escherichia coli Strains Recovered from Human Cystitis and Pyelonephritis Infections in Transurethrally Challenged Mice

Infection and Immunity ◽

10.1128/iai.66.7.3059-3065.1998 ◽

1998 ◽

Vol 66 (7) ◽

pp. 3059-3065 ◽

Cited By ~ 52

Author(s):

David E. Johnson ◽

C. Virginia Lockatell ◽

Robert G. Russell ◽

J. Richard Hebel ◽

Michael D. Island ◽

...

Keyword(s):

Escherichia Coli ◽

Urinary Tract ◽

Virulence Factors ◽

Bacterial Infections ◽

Clinical Symptoms ◽

Epidemiological Studies ◽

In Vivo Studies ◽

E Coli ◽

Tract Infections

ABSTRACT Urinary tract infection, most frequently caused byEscherichia coli, is one of the most common bacterial infections in humans. A vast amount of literature regarding the mechanisms through which E. coli induces pyelonephritis has accumulated. Although cystitis accounts for 95% of visits to physicians for symptoms of urinary tract infections, few in vivo studies have investigated possible differences between E. coli recovered from patients with clinical symptoms of cystitis and that from patients with symptoms of pyelonephritis. Epidemiological studies indicate that cystitis-associated strains appear to differ from pyelonephritis-associated strains in elaboration of some putative virulence factors. With transurethrally challenged mice we studied possible differences using three each of the most virulent pyelonephritis and cystitis E. coli strains in our collection. The results indicate that cystitis strains colonize the bladder more rapidly than do pyelonephritis strains, while the rates of kidney colonization are similar. Cystitis strains colonize the bladder in higher numbers, induce more pronounced histologic changes in the bladder, and are more rapidly eliminated from the mouse urinary tract than pyelonephritis strains. These results provide evidence that cystitis strains differ from pyelonephritis strains in this model, that this model is useful for the study of the uropathogenicity of cystitis strains, and that it would be unwise to use pyelonephritis strains to study putative virulence factors important in the development of cystitis.

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Post-antibiotic era in hemodialysis? Two case reports of simultaneous colonization and bacteremia by multidrug-resistant bacteria

Brazilian Journal of Nephrology ◽

10.1590/2175-8239-jbn-2020-0070 ◽

2020 ◽

Author(s):

Johanna M. Vanegas ◽

Lorena Salazar-Ospina ◽

Gustavo A. Roncancio ◽

Julián Builes ◽

Judy Natalia Jiménez

Keyword(s):

Pseudomonas Aeruginosa ◽

Bacterial Infections ◽

Case Reports ◽

Multidrug Resistant ◽

Resistance Mechanisms ◽

Control Measures ◽

Resistant Bacteria ◽

Multidrug Resistant Bacteria ◽

E Coli ◽

Carbapenem Resistant

ABSTRACT The emergence of resistance mechanisms not only limits the therapeutic options for common bacterial infections but also worsens the prognosis in patients who have conditions that increase the risk of bacterial infections. Thus, the effectiveness of important medical advances that seek to improve the quality of life of patients with chronic diseases is threatened. We report the simultaneous colonization and bacteremia by multidrug-resistant bacteria in two hemodialysis patients. The first patient was colonized by carbapenem- and colistin-resistant Klebsiella pneumoniae, carbapenem-resistant Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus (MRSA). The patient had a bacteremia by MRSA, and molecular typing methods confirmed the colonizing isolate was the same strain that caused infection. The second case is of a patient colonized by extended-spectrum beta-lactamases (ESBL)-producing Escherichia coli and carbapenem-resistant Pseudomonas aeruginosa. During the follow-up period, the patient presented three episodes of bacteremia, one of these caused by ESBL-producing E. coli. Molecular methods confirmed colonization by the same clone of ESBL-producing E. coli at two time points, but with a different genetic pattern to the strain isolated from the blood culture. Colonization by multidrug-resistant bacteria allows not only the spread of these microorganisms, but also increases the subsequent risk of infections with limited treatments options. In addition to infection control measures, it is important to establish policies for the prudent use of antibiotics in dialysis units.

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Bactericidal Efficacy of Meropenem in Combination with Cefmetazole against IMP-producing Carbapenem-Resistant Enterobacteriaceae

10.21203/rs.2.15806/v2 ◽

2019 ◽

Author(s):

Ryuichiro Abe ◽

Hideharu Hagiya ◽

Yukihiro Akeda ◽

Norihisa Yamamoto ◽

Yoshikazu Ishii ◽

...

Keyword(s):

Combination Therapy ◽

Animal Studies ◽

Bactericidal Effect ◽

E Coli ◽

Carbapenem Resistant ◽

Enterobacter Hormaechei ◽

Time Kill ◽

Carbapenem Resistant Enterobacteriaceae

Abstract Objective: Carbapenem-resistant Enterobacteriaceae (CRE) are among the most severe threats to public and clinical health because of their high levels of resistance to various antibiotics. We assessed the efficacy of combination therapy with meropenem (MEM) and cefmetazole (CMZ) against Imipenemase (IMP)-producing CRE, using the checkerboard method and time-killing assay on 13 Enterobacteriaceae isolates harboring blaIMP-1 (4 Enterobacter hormaechei, 5 Escherichia coli, and 4 Klebsiella pneumoniae isolates) and 13 isolates harboring blaIMP-6 (8 E. coli and 5 K. pneumoniae isolates). Results: Minimum inhibitory concentrations (MICs) of MEM and CMZ ranged from 2 to 64 and 64 to 2048 μg/mL, respectively. Checkerboard method demonstrated the synergy of the MEM/CMZ combination in all the tested IMP-producing CRE isolates, and the time-kill assay indicated a bactericidal effect for both blaIMP-1 and blaIMP-6 positive CRE when MEM/CMZ combination was used. In vitro, the MEM/CMZ combination was potentially effective against IMP-1- or IMP-6-producing CRE. Further investigations including in vivo animal studies and clinical studies are warranted to corroborate the clinical utility of the novel combination therapy.

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2134. Differential Changes in Breath Volatile Metabolites to Identify Carbapenem-Resistant Enterobacteriaceae (CRE) in a Murine Pneumonia Model

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.1814 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S722-S723

Author(s):

Nour Ismail ◽

Hazem Albashash ◽

Mahesh J Thalavitiya Acharige ◽

Mohamad Hejazi ◽

Carmen Leon Astudillo ◽

...

Keyword(s):

Bacterial Species ◽

Rapid Identification ◽

Metabolic Responses ◽

P Value ◽

Species Pair ◽

E Coli ◽

Volatile Metabolites ◽

Carbapenem Resistant ◽

Carbapenem Resistant Enterobacteriaceae

Abstract Background CRE infections cause significant mortality, in large part because rapid identification of these infections is challenging. We tested the hypothesis that CRE and their isogenic carbapenem-susceptible counterparts have differential metabolic responses to carbapenem therapy. Methods We generated isogenic pairs of E. coli, E. cloacae, and K. pneumoniae by inserting a blaNDM-1-containing plasmid into carbapenem-susceptible E. coli, E. cloacae, and K. pneumoniae. We confirmed phenotypic meropenem (MPM) resistance per CLSI breakpoints for Enterobacteriaceae (MIC ≥4) in the NDM-1+ member and susceptibility (MIC≤1) in the NDM-1- member of each pair. We administered 2 × 108 CFU of each isolate intranasally to 23–28 g male C57BL/6J mice, infecting 6 mice with the NDM-1+ member and 6 with the NDM-1− member of each species pair (12 mice per bacterial species). 24 hours after infection, we treated 3 mice in each NDM-1+ and NDM-1− bacterial species cohort with MPM over 4 hours, and the other 3 mice in each cohort with saline over 4 hours as controls, confirming adequate infection (a target of 106 CFU/g of lung tissue) in quantitative lung homogenate cultures. We then collected breath samples from each mouse via tracheostomy using a murine ventilator, identifying all volatile metabolites in each sample using thermal desorption-gas chromatography/tandem mass spectrometry. We used Wilcoxon tests to examine differences in metabolite abundance between MPM and saline-treated control mice in the NDM-1+ and NDM-1− a member of each species pair, with a two-sided P-value threshold of < 0.1. Results Several breath volatile metabolites changed differentially within each NDM-1+/NDM-1- pair, outlined in Table 1 (E. coli), Table 2 (E. cloacae), and Table 3 (K. pneumoniae). Each listed metabolite that changed with MPM did not change with MPM in mice infected with each isogenic counterpart Conclusion There are differential in vivo metabolic responses with effective vs. ineffective treatment of mice with pneumonia caused by E. coli, E. cloacae, and K. pneumoniae pairs that are genetically identical other than blaNDM-1; this differential treatment response can potentially be used to identify these infections. Disclosures All authors: No reported disclosures.

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Ablation of the Tamm-Horsfall protein gene increases susceptibility of mice to bladder colonization by type 1-fimbriatedEscherichia coli

AJP Renal Physiology ◽

10.1152/ajprenal.00357.2003 ◽

2004 ◽

Vol 286 (4) ◽

pp. F795-F802 ◽

Cited By ~ 110

Author(s):

Lan Mo ◽

Xin-Hua Zhu ◽

Hong-Ying Huang ◽

Ellen Shapiro ◽

David L. Hasty ◽

...

Keyword(s):

Defense Mechanisms ◽

Bacterial Infections ◽

Uropathogenic Escherichia Coli ◽

Major Protein ◽

E Coli ◽

Deficient Mice ◽

Adhesion Process

The adhesion of uropathogenic Escherichia coli to the urothelial surface of the bladder is a prerequisite for the establishment of bladder infections. This adhesion process relies on E. coli adhesins and their cognate urothelial receptors, and it also is influenced by an intricate array of defense mechanisms of the urinary system. In this study, we examined the in vivo role of Tamm-Horsfall protein (THP), the most abundant urinary protein, in innate urinary defense. We genetically ablated the mouse THP gene and found that THP deficiency predisposes mice to bladder infections by type 1-fimbriated E. coli. Inoculation of too few type 1-fimbriated E. coli to colonize wild-type mice caused significant bladder colonization in THP-knockout mice. In contrast, THP deficiency did not enhance the ability of P-fimbriated E. coli to colonize the bladder. Our results provide the first in vivo evidence indicating that under physiological conditions, the mannosylated THP can serve as an effective soluble “receptor,” binding to the type 1-fimbriated E. coli and competitively inhibiting them from adhering to the uroplakin Ia receptors present on the urothelial surface. These results suggest that potential THP defects, either quantitative or qualitative, could predispose the urinary bladder to bacterial infections. The generation of THP-deficient mice established the role of THP as a first line of urinary defense and should help elucidate other potential functions of this major protein in urinary tract physiology and diseases.

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Use of Inteins for the In Vivo Production of Stable Cyclic Peptide Libraries in E. coli

E. coli Gene Expression Protocols ◽

10.1385/1-59259-301-1:281 ◽

2003 ◽

pp. 281-294 ◽

Cited By ~ 1

Author(s):

Ernesto Abel-Santos ◽

Charles P. Scott ◽

Stephen J. Benkovic

Keyword(s):

Cyclic Peptide ◽

Peptide Libraries ◽

E Coli

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In vitro and in vivo antibacterial efficacies of CFC-222, a new fluoroquinolone.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.41.10.2209 ◽

1997 ◽

Vol 41 (10) ◽

pp. 2209-2213 ◽

Cited By ~ 12

Author(s):

J H Kim ◽

J A Kang ◽

Y G Kim ◽

J W Kim ◽

J H Lee ◽

...

Keyword(s):

Bacterial Infections ◽

Protective Efficacy ◽

Horse Serum ◽

The Other ◽

Infection Model ◽

Gram Positive ◽

Gram Negative ◽

E Coli

CFC-222 is a novel fluoroquinolone containing a C-7 bicyclic amine moiety with potent antibacterial activities against gram-positive, gram-negative, and anaerobic organisms. We compared the in vitro and in vivo activities of CFC-222 with those of ciprofloxacin, ofloxacin, and lomefloxacin. CFC-222 was more active than the other fluoroquinolones tested against gram-positive bacteria. CFC-222 was particularly active against Streptococcus pneumoniae (MIC at which 90% of isolates are inhibited [MIC90], 0.2 microg/ml), Staphylococcus aureus (MIC90, 0.2 microg/ml for ciprofloxacin-susceptible strains), and Enterococcus faecalis (MIC90, 0.39 microg/ml). Against Escherichia coli and other members of the family Enterobacteriaceae, CFC-222 was slightly less active than ciprofloxacin (MIC90s for E. coli, 0.1 and 0.025 microg/ml, respectively). The in vitro activity of CFC-222 was not influenced by inoculum size, medium composition, or the presence of horse serum. However, its activity was decreased significantly by a change in the pH of the medium from 7.0 to 6.0, as was the case for the other quinolones tested. The in vivo protective efficacy of CFC-222 by oral administration was greater than those of the other quinolones tested in a mouse model of intraperitoneally inoculated systemic infection caused by S. aureus. CFC-222 exhibited efficacy comparable to that of ciprofloxacin in the same model of infection caused by gram-negative organisms, such as E. coli and Klebsiella pneumoniae. In this infection model, CFC-222 was slightly less active than ciprofloxacin against Pseudomonas aeruginosa. These results suggest that CFC-222 may be a promising therapeutic agent in various bacterial infections.

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