scholarly journals Fighting Antibiotic-Resistant Klebsiella pneumoniae with “Sweet” Immune Targets

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Roberto Adamo ◽  
Immaculada Margarit

ABSTRACT Antibiotics and vaccines have greatly impacted human health in the last century by dramatically reducing the morbidity and mortality associated with infectious diseases. The recent challenge posed by the emergence of multidrug-resistant bacteria could possibly be addressed by novel immune prophylactic and therapeutic approaches. Among the newly threatening pathogens, Klebsiella pneumoniae is particularly worrisome in the nosocomial setting, and its surface polysaccharides are regarded as promising antigen candidates. The majority of Klebsiella carbapenem-resistant strains belong to the sequence type 158 (ST258) lineage, with two main clades expressing capsular polysaccharides CPS1 and CPS2. In a recent article, S. D. Kobayashi and colleagues (mBio 9:e00297-18, 2018, https://doi.org/10.1128/mBio.00297-18) show that CPS2-specific IgGs render ST258 clade 2 bacteria more sensitive to human serum and phagocytic killing. E. Diago-Navarro et al. (mBio 9:e00091-18, 2018, https://doi.org/10.1128/mBio.00091-18) generated two murine monoclonal antibodies recognizing distinct glycotopes of CPS2 that presented functional activity against multiple ST258 strains. These complementary studies represent a step toward the control of this dangerous pathogen.

2019 ◽  
Vol 8 (19) ◽  
Author(s):  
Katherine T. Nguyen ◽  
Rachele Bonasera ◽  
Garret Benson ◽  
Adriana C. Hernandez-Morales ◽  
Jason J. Gill ◽  
...  

May is a newly isolated myophage that infects multidrug-resistant strains of Klebsiella pneumoniae, a pathogen that is associated with antibiotic-resistant infections in humans. The genome of May has been shown to be similar to that of phage Vi01.


2021 ◽  
Author(s):  
Anke Breine ◽  
Megane Van Gysel ◽  
Mathias Elsocht ◽  
Clemence Whiteway ◽  
Chantal Philippe ◽  
...  

Synopsis Objectives: The spread of antibiotic resistant bacteria is an important threat for human healthcare. Acinetobacter baumannii bacteria impose one of the major issues, as multidrug- to pandrug-resistant strains have been found, rendering some infections untreatable. In addition, A. baumannii is a champion in surviving in harsh environments, being capable of resisting to disinfectants and to persist prolonged periods of desiccation. Due to the high degree of variability found in A. baumannii isolates, the search for new antibacterials is challenging. Here, we screened a compound library to identify compounds active against recent isolates of A. baumannii bacteria. Methods: A repurposing drug screen was undertaken to identify A. baumannii growth inhibitors. One hit was further characterized by determining its IC50 and testing its activity on 43 recent clinical A. baumannii isolates, amongst which 40 are extensively drug- and carbapenem-resistant strains. Results: The repurposing screen led to the identification of a harmine-derived compound, called HDC1, which proved to have bactericidal activity on the multidrug-resistant AB5075-VUB reference strain with an IC50 of 48.23 [mu]M. In addition, HDC1 impairs growth of all 43 recent clinical A. baumannii isolates. Conclusions: We identified a compound with inhibitory activity on all tested, extensively drug-resistant clinical A. baumannii isolates.


mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Elizabeth Diago-Navarro ◽  
Michael P. Motley ◽  
Gonzalo Ruiz-Peréz ◽  
Winnie Yu ◽  
Julianne Austin ◽  
...  

ABSTRACTCarbapenem-resistant (CR) sequence type 258 (ST258)Klebsiella pneumoniaehas become an urgent health care threat, causing an increasing number of high-mortality infections. Its resistance to numerous antibiotics and threat to immunocompromised patients necessitate finding new therapies to combat these infections. Previous successes in the laboratory, as well as the conservation of capsular polysaccharide (CPS) among the members of the ST258 clone, suggest that monoclonal antibody (MAb) therapy targeting the outer polysaccharide capsule ofK. pneumoniaecould serve as a valuable treatment alternative for afflicted patients. Here, we isolated several IgG antibodies from mice inoculated with a mixture of CRK. pneumoniaeCPS conjugated to anthrax protective antigen. Two of these MAbs, 17H12 and 8F12, bind whole and oligosaccharide epitopes of the CPS of clade 2 ST258 CRK. pneumoniae, which is responsible for the most virulent CRK. pneumoniaeinfections in the United States. These antibodies were shown to agglutinate all clade 2 strains and were also shown to promote extracellular processes killing these bacteria, including biofilm inhibition, complement deposition, and deployment of neutrophil extracellular traps. Additionally, they promoted opsonophagocytosis and intracellular killing of CRK. pneumoniaeby human-derived neutrophils and cultured murine macrophages. Finally, when mice were intratracheally infected with preopsonized clade 2 CRK. pneumoniae, these MAbs reduced bacterial dissemination to organs. Our data suggest that broadly reactive anticapsular antibodies and vaccines against clade 2 ST258 CRK. pneumoniaeare possible. Such MAbs and vaccines would benefit those susceptible populations at risk of infection with this group of multidrug-resistant bacteria.IMPORTANCECarbapenem-resistantKlebsiella pneumoniaeis an enteric bacterium that has been responsible for an increasing number of deadly outbreaks and hospital-acquired infections. The pathogen’s resistance to numerous antibiotics, including new drugs, leaves few therapeutic options available for infected patients, who often are too sick to fight the infection themselves. Immunotherapy utilizing monoclonal antibodies has been successful in other medical fields, and antibodies targeting the outer polysaccharide capsule of these bacteria could be a valuable treatment alternative. This study presents two anticapsular antibodies, 17H12 and 8F12, that were found to be protective against the most virulent carbapenem-resistantK. pneumoniaeclinical strains. These antibodies are shown to promote the killing of these strains through several extracellular and intracellular processes and prevent the spread of infection in mice from the lungs to distal organs. Thus, they could ultimately treat or protect patients infected or at risk of infection by this multidrug-resistant bacterium.


2013 ◽  
Vol 57 (8) ◽  
pp. 3990-3993 ◽  
Author(s):  
Carlo Tascini ◽  
Enrico Tagliaferri ◽  
Tommaso Giani ◽  
Alessandro Leonildi ◽  
Sarah Flammini ◽  
...  

ABSTRACTInfections caused by carbapenem-resistant KPC-producingKlebsiella pneumoniaeare responsible for high rates of mortality and represent a major therapeutic challenge, especially when the isolates are also resistant to colistin. We used the checkerboard method to evaluate the synergistic activity of 10 antibiotic combinations against 13 colistin-resistant KPC-producingK. pneumoniaeisolates (colistin MIC range of 8 to 128 mg/liter). Colistin plus rifampin was the only combination that demonstrated consistent synergistic bacteriostatic activity against 13/13 strains tested, reducing the colistin MIC below the susceptibility breakpoint (MIC ≤ 2 mg/liter) in 7/13 strains at rifampin concentrations ranging from 4 to 16 mg/liter. Bactericidal synergistic activity was also documented for 8/13 tested strains. Other antimicrobial combinations with carbapenems, gentamicin, and tigecycline showed variously synergistic results. Colistin plus rifampin also exhibited bacteriostatic synergistic activity against 4/4 colistin-susceptible KPC-producingK. pneumoniaeisolates (colistin MIC range of 0.5 to 2 mg/liter) and 4/4 ertapenem-resistant extended-spectrum beta-lactamase (ESBL)-producingK. pneumoniaeisolates (ertapenem MIC range of 16 to 32 mg/liter). Collectively, our data suggest that colistin plus rifampin is the most consistently synergistic combination against KPC-producingK. pneumoniaeisolates, including colistin-resistant strains. Colistin-rifampin combinations may have a role in the treatment of multidrug-resistantK. pneumoniaeand may possibly slow the selection of heteroresistant subpopulations during colistin therapy.


Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 495
Author(s):  
Masateru Nishiyama ◽  
Susan Praise ◽  
Keiichi Tsurumaki ◽  
Hiroaki Baba ◽  
Hajime Kanamori ◽  
...  

There is increasing attention toward factors that potentially contribute to antibiotic resistance (AR), as well as an interest in exploring the emergence and occurrence of antibiotic resistance bacteria (ARB). We monitored six ARBs that cause hospital outbreaks in wastewater influent to highlight the presence of these ARBs in the general population. We analyzed wastewater samples from a municipal wastewater treatment plant (MWWTP) and hospital wastewater (HW) for six species of ARB: Carbapenem-resistant Enterobacteria (CARBA), extended-spectrum β-lactamase producing Enterobacteria (ESBL), multidrug-resistant Acinetobacter (MDRA), multidrug-resistant Pseudomonas aeruginosa (MDRP), methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococci (VRE). We registered a high percentage of ARBs in MWWTP samples (>66%) for all ARBs except for MDRP, indicating a high prevalence in the population. Percentages in HW samples were low (<78%), and no VRE was detected throughout the study. CARBA and ESBL were detected in all wastewater samples, whereas MDRA and MRSA had a high abundance. This result demonstrated the functionality of using raw wastewater at MWWTP to monitor the presence and extent of ARB in healthy populations. This kind of surveillance will contribute to strengthening the efforts toward reducing ARBs through the detection of ARBs to which the general population is exposed.


2020 ◽  
Vol 6 (12) ◽  
Author(s):  
Katlego Kopotsa ◽  
Nontombi M. Mbelle ◽  
John Osei Sekyere

Carbapenem-resistant Klebsiella pneumoniae (CRKP) remains a major clinical pathogen and public health threat with few therapeutic options. The mobilome, resistome, methylome, virulome and phylogeography of CRKP in South Africa and globally were characterized. CRKP collected in 2018 were subjected to antimicrobial susceptibility testing, screening by multiplex PCR, genotyping by repetitive element palindromic (REP)-PCR, plasmid size, number, incompatibility and mobility analyses, and PacBio’s SMRT sequencing (n=6). There were 56 multidrug-resistant CRKP, having bla OXA-48-like and bla NDM-1/7 carbapenemases on self-transmissible IncF, A/C, IncL/M and IncX3 plasmids endowed with prophages, traT, resistance islands, and type I and II restriction modification systems (RMS). Plasmids and clades detected in this study were respectively related to globally established/disseminated plasmids clades/clones, evincing transboundary horizontal and vertical dissemination. Reduced susceptibility to colistin occurred in 23 strains. Common clones included ST307, ST607, ST17, ST39 and ST3559. IncFIIk virulent plasmid replicon was present in 56 strains. Whole-genome sequencing of six strains revealed least 41 virulence genes, extensive ompK36 mutations, and four different K- and O-loci types: KL2, KL25, KL27, KL102, O1, O2, O4 and O5. Types I, II and III RMS, conferring m6A (G A TC, G A TGNNNNNNTTG, CA A NNNNNNCATC motifs) and m4C (C C WGG) modifications on chromosomes and plasmids, were found. The nature of plasmid-mediated, clonal and multi-clonal dissemination of blaOXA-48-like and blaNDM-1 mirrors epidemiological trends observed for closely related plasmids and sequence types internationally. Worryingly, the presence of both bla OXA-48 and bla NDM-1 in the same isolates was observed. Plasmid-mediated transmission of RMS, virulome and prophages influence bacterial evolution, epidemiology, pathogenicity and resistance, threatening infection treatment. The influence of RMS on antimicrobial and bacteriophage therapy needs urgent investigation.


2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Thea Brennan-Krohn ◽  
Alejandro Pironti ◽  
James E. Kirby

ABSTRACTResistance to colistin, a polypeptide drug used as an agent of last resort for the treatment of infections caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria, including carbapenem-resistantEnterobacteriaceae(CRE), severely limits treatment options and may even transform an XDR organism into one that is pan-resistant. We investigated the synergistic activity of colistin in combination with 19 antibiotics against a collection of 20 colistin-resistantEnterobacteriaceaeisolates, 15 of which were also CRE. All combinations were tested against all strains using an inkjet printer-assisted digital dispensing checkerboard array, and the activities of those that demonstrated synergy by this method were evaluated against a single isolate in a time-kill synergy study. Eighteen of 19 combinations demonstrated synergy against two or more isolates, and the 4 most highly synergistic combinations (colistin combined with linezolid, rifampin, azithromycin, and fusidic acid) were synergistic against ≥90% of strains. Sixteen of 18 combinations (88.9%) that were synergistic in the checkerboard array were also synergistic in a time-kill study. Our findings demonstrate that colistin in combination with a range of antibiotics, particularly protein and RNA synthesis inhibitors, exhibits synergy against colistin-resistant strains, suggesting that colistin may exert a subinhibitory permeabilizing effect on the Gram-negative bacterial outer membrane even in isolates that are resistant to it. These findings suggest that colistin combination therapy may have promise as a treatment approach for patients infected with colistin-resistant XDR Gram-negative pathogens.


2019 ◽  
Vol 63 (4) ◽  
Author(s):  
W. J. Weiss ◽  
M. E. Pulse ◽  
P. Nguyen ◽  
E. J. Growcott

ABSTRACT LYS228 has potent antibacterial activity against carbapenem-resistant strains of Enterobacteriaceae. LYS228 was efficacious in neutropenic thigh models established with Klebsiella pneumoniae producing KPC-2 or NDM-1; pretreatment with uranyl nitrate considerably shifted calculated static doses of LYS228. In murine ascending pyelonephritis, LYS228 reduced bacterial burden in kidney, urine, and bladder. The successful treatment of murine infection models established with carbapenem-resistant K. pneumoniae further supports the clinical development of LYS228.


2018 ◽  
Vol 6 (16) ◽  
pp. e00167-18 ◽  
Author(s):  
Revathy Arushothy ◽  
Norazah Ahmad ◽  
Fairuz Amran ◽  
Rohaidah Hashim ◽  
Nazirah Samsuddin ◽  
...  

ABSTRACTAfter the introduction of the pneumococcal conjugate vaccine in Malaysia in recent years, the emergence of nonvaccine serotypes is of concern, particularly the antibiotic-resistant strains, with an increase specifically in serotype 15A. Here, we report the draft genome sequence ofStreptococcus pneumoniaestrain SS40_16, isolated from the blood sample of a 19-month-old female in 2016. SS40_16 is a multidrug-resistant strain with resistance to penicillin (MIC, ≥2 µg/ml), tetracycline, and trimethoprim-sulfamethoxazole. The strain belongs to serotype 15A and sequence type 1591 (ST1591).


2014 ◽  
Vol 58 (6) ◽  
pp. 3085-3090 ◽  
Author(s):  
Hosam M. Zowawi ◽  
Anna L. Sartor ◽  
Hanan H. Balkhy ◽  
Timothy R. Walsh ◽  
Sameera M. Al Johani ◽  
...  

ABSTRACTThe molecular epidemiology and mechanisms of resistance of carbapenem-resistantEnterobacteriaceae(CRE) were determined in hospitals in the countries of the Gulf Cooperation Council (GCC), namely, Saudi Arabia, United Arab Emirates, Oman, Qatar, Bahrain, and Kuwait. Isolates were subjected to PCR-based detection of antibiotic-resistant genes and repetitive sequence-based PCR (rep-PCR) assessments of clonality. Sixty-two isolates which screened positive for potential carbapenemase production were assessed, and 45 were found to produce carbapenemase. The most common carbapenemases were of the OXA-48 (35 isolates) and NDM (16 isolates) types; 6 isolates were found to coproduce the OXA-48 and NDM types. No KPC-type, VIM-type, or IMP-type producers were detected. Multiple clones were detected with seven clusters of clonally relatedKlebsiella pneumoniae. Awareness of CRE in GCC countries has important implications for controlling the spread of CRE in the Middle East and in hospitals accommodating patients transferred from the region.


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