Glycopeptide Antibiotic To Overcome the Intrinsic Resistance of Gram-Negative Bacteria.

The emergence of drug resistance along with a declining pipeline of clinically useful antibiotics has made it vital to develop more effective antimicrobial therapeutics, particularly against difficult-to-treat Gram-negative pathogens (GNPs). Many antibacterial agents, including glycopeptide antibiotics such as vancomycin, are inherently inactive toward GNPs because of their inability to cross the outer membrane of these pathogens. Here, we demonstrate, for the first time, lipophilic cationic (permanent positive charge) vancomycin analogues were able to permeabilize the outer membrane of GNPs and overcome the inherent resistance of GNPs toward glycopeptides.

Aryl-alkyl-lysines: Membrane-Active Small Molecules Active against Murine Model of Burn Infection.

Infections caused by drug-resistant Gram-negative pathogens continue to be significant contributors to human morbidity. The recent advent of New Delhi metallo-β-lactamase-1 (blaNDM-1) producing pathogens, against which few drugs remain active, has aggravated the problem even further. This paper shows that aryl-alkyl-lysines, membrane-active small molecules, are effective in treating infections caused by Gram-negative pathogens.

Chitosan Derivatives Active against Multidrug-Resistant Bacteria and Pathogenic Fungi: In Vivo Evaluation as Topical Antimicrobials.

The continuous rise of antimicrobial resistance and the dearth of new antibiotics in the clinical pipeline raise an urgent call for the development of potent antimicrobial agents. Cationic chitosan derivatives, N-(2-hydroxypropyl)-3-trimethylammonium chitosan chlorides (HTCC), have been widely studied as potent antibacterial agents. However, their systemic structure-activity relationship, activity toward drug-resistant bacteria and fungi, and mode of action are very rare.

Side Chain Degradable Cationic-Amphiphilic Polymers with Tunable Hydrophobicity Show in Vivo Activity.

Cationic-amphiphilic antibacterial polymers with optimal amphiphilicity generally target the bacterial membranes instead of mammalian membranes. To date, this balance has been achieved by varying the cationic charge or side chain hydrophobicity in a variety of cationic-amphiphilic polymers. Optimal hydrophobicity of cationic-amphiphilic polymers has been considered as the governing factor for potent antibacterial activity yet minimal mammalian cell toxicity.

Reverse transcription loop-mediated isothermal amplification assays for rapid identification of eastern and western strains of bluetongue virus in India.

Bluetongue virus (BTV) infects all ruminants, including cattle, goats and camelids, causing bluetongue disease (BT) that is often severe in naïve deer and sheep. Reverse-transcription-loop-mediated-isothermal-amplification (RT-LAMP) assays were developed to detect eastern or western topotype of BTV strains circulating in India. Each assay uses four primers recognizing six distinct sequences of BTV genome-segment 1 (Seg-1).

Loop-mediated isothermal amplification assay for rapid and sensitive detection of sheep pox and goat pox viruses in clinical samples.

A Loop-mediated isothermal amplification (LAMP) assay targeting the highly conserved DNA polymerase gene of capripox virus genome was developed and evaluated for rapid detection of sheep pox and goat pox viruses. The optimized LAMP assay is found specific and sensitive for amplification of target DNA with a diagnostic sensitivity and specificity of 96.6% and 100% respectively compared to quantitative PCR.

Aryl-Alkyl-Lysines: Agents That Kill Planktonic Cells, Persister Cells, Biofilms of MRSA and Protect Mice from Skin-Infection.

Development of synthetic strategies to combat Staphylococcal infections, especially those caused by methicillin resistant Staphyloccus aureus (MRSA), needs immediate attention. In this manuscript we report the ability of aryl-alkyl-lysines, simple membrane active small molecules, to treat infections caused by planktonic cells, persister cells and biofilms of MRSA. A representative compound, NCK-10, did not induce development of resistance in planktonic cells in multiple passages and retained activity in varying environments of pH and salinity.

Farm Community Impacts of Foot-and-Mouth Disease Outbreaks in Cattle and Buffaloes in Karnataka State, India.

This study was conducted to assess the impact of Foot-and-mouth Disease (FMD) outbreak in cattle and buffaloes on farming community in Kolar district, Karnataka state, India. Primary data were collected using pre-tested schedule from 178 sample farms using multistage random cluster sample technique. The results revealed that 78% of surveyed villages were affected with FMD.

Membrane Disruption and Enhanced Inhibition of Cell-Wall Biosynthesis: A Synergistic Approach to Tackle Vancomycin-Resistant Bacteria.

Resistance to glycopeptide antibiotics, the drugs of choice for life-threatening bacterial infections, is on the rise. In order to counter the threat of glycopeptide-resistant bacteria, we report development of a new class of semi-synthetic glycopeptide antibiotics, which not only target the bacterial membrane but also display enhanced inhibition of cell-wall biosynthesis through increased binding affinity to their target peptides. The combined effect of these two mechanisms resulted in improved in vitro activity of two to three orders of magnitude over vancomycin and no propensity to trigger drug resistance in bacteria.

Amide side chain amphiphilic polymers disrupt surface established bacterial bio-films and protect mice from chronic Acinetobacter baumannii infection.

Bacterial biofilms represent the root-cause of chronic or persistent infections in humans. Gram-negative bacterial infections due to nosocomial and opportunistic pathogens such as Acinetobacter baumannii are more difficult to treat because of their inherent and rapidly acquiring resistance to antibiotics. Due to biofilm formation, A.

Cross-sectional study indicates nearly a quarter of sheep population in Karnataka state of India is infected with ovine herpesvirus 2.

In a cross-sectional study, prevalence of ovine herpesvirus 2 (family: Herpesviridae, subfamily: Gammaherpesvirinae, genus Macavirus and species: Ovine herpesvirus 2) infection was estimated in sheep population of Karnataka state in India. Based on the three stage cluster sampling method, whole blood samples (356) of sheep were collected from 11 sheep-dense districts of the state. The samples were tested for presence of OvHV-2 genome by recommended hemi-nested polymerase chain reaction (PCR) test.

Genetic clustering of recent classical swine fever virus isolates from Karnataka, India revealed the emergence of subtype 2.2 replacing subtype 1.1.

The phylogenetic analysis of 11 CSFV isolates from Karnataka, India obtained during the year 2012-13 was undertaken to obtain the most reliable genetic typing of the CSFV isolates based on E2, NS5B and 5'UTR genomic regions. The study indicated that all the 11 CSFV isolates belonged to subgroup 2.2.

In vivo efficacy and pharmacological properties of a novel glycopeptide (YV4465) against vancomycin-intermediate Staphylococcus aureus.

Infections caused by vancomycin-intermediate Staphylococcus aureus (VISA) are associated with high rates of vancomycin treatment failure. The lipophilic vancomycin-carbohydrate conjugate YV4465 is a new glycopeptide antibiotic that is active against a variety of clinically relevant multidrug-resistant Gram-positive pathogens in vitro. YV4465 was 50- and 1000-fold more effective than vancomycin against VISA and vancomycin-resistant enterococci, respectively.

Full-Genome Sequencing as a Basis for Molecular Epidemiology Studies of Bluetongue Virus in India.

Since 1998 there have been significant changes in the global distribution of bluetongue virus (BTV). Ten previously exotic BTV serotypes have been detected in Europe, causing severe disease outbreaks in naïve ruminant populations. Previously exotic BTV serotypes were also identified in the USA, Israel, Australia and India.

Comparative evaluation of recombinant LigB protein and heat-killed antigen-based latex agglutination test with microscopic agglutination test for diagnosis of bovine leptospirosis.

This study aimed to develop latex agglutination test (LAT) using recombinant leptospiral immunoglobulin-like protein (LigB) (rLigB) antigen and compare its diagnostic efficacy with LAT using conventional heat-killed leptospiral antigen and microscopic agglutination test (MAT) in diagnosing bovine leptospirosis. The PCR-amplified 1053-bp ligB gene sequences from Leptospira borgpetersenii Hardjo serovar were cloned in pET 32 (a) vector at EcoRI and NotI sites and expressed in BL21 E. coli cells as fusion protein with thioredoxin (-57 kDa) and characterized by SDS-PAGE and immunoblot.

In vivo antibacterial activity and pharmacological properties of the membrane-active glycopeptide antibiotic YV11455.

The membrane-active glycopeptide antibiotic YV11455 is a lipophilic cationic vancomycin analogue that demonstrates rapid and concentration-dependent killing of clinically relevant multidrug-resistant (MDR) Gram-positive bacteria in vitro. YV11455 was 2-fold and 54-270-fold more effective than vancomycin against clinical isolates of vancomycin-sensitive and vancomycin-resistant bacteria, respectively. In this study, the in vivo efficacy, pharmacodynamics, pharmacokinetics and acute toxicology of YV11455 were investigated.

Genome Sequence of Bluetongue Virus Type 2 from India: Evidence for Reassortment between Outer Capsid Protein Genes.

Southern Indian isolate IND1994/01 of bluetongue virus serotype 2 (BTV-2), from the Orbivirus Reference Collection at the Pirbright Institute (http://www.reoviridae.org/dsRNA_virus_proteins/ReoID/btv-2.

Membrane-active macromolecules resensitize NDM-1 gram-negative clinical isolates to tetracycline antibiotics.

Gram-negative 'superbugs' such as New Delhi metallo-beta-lactamase-1 (blaNDM-1) producing pathogens have become world's major public health threats. Development of molecular strategies that can rehabilitate the 'old antibiotics' and halt the antibiotic resistance is a promising approach to target them. We report membrane-active macromolecules (MAMs) that restore the antibacterial efficacy (enhancement by >80-1250 fold) of tetracycline antibiotics towards blaNDM-1 Klebsiella pneumonia and blaNDM-1 Escherichia coli clinical isolates.

Prevalence of peste des petits ruminants in goats in North-East India.

The present study describes prevalence of peste des petits ruminants (PPR) virus infection in goats in various parts of North-East (NE) India by screening of suspected serum samples collected during outbreak investigation and random samples during 2013-2014 survey. A total of 391 serum samples (318 random and 73 outbreak/suspected) were collected from 28 districts in 7 states (Meghalaya, Assam, Manipur, Nagaland, Arunachal Pradesh, Tripura and Mizoram) of NE India. Serum samples were screened for PPRV-specific antibodies by using PPR monoclonal-antibody based competitive ELISA.

Detection of subclinical peste des petits ruminants virus infection in experimental cattle.

The present study was undertaken to investigate the possible involvement of cattle in the epidemiology of peste des petits ruminants (PPR) as subclinical carriers. Cattle were exposed experimentally to PPR virus (PPRV) infection or placed in contact with PPR infected goats. Clinical samples including heparinized/EDTA blood, plasma, peripheral blood monocyte cells (PBMCs) and clotted blood (for serum) were collected periodically from 21 days post infection (dpi) to 397 dpi (21, 45, 50, 57, 65, 95, 111, 119, 148, 190, 203 and 397 dpi) and tested for PPRV antigen, nucleic acid and antibody.

Protective immune response of live attenuated thermo-adapted peste des petits ruminants vaccine in goats.

Virulent isolate of peste des petits ruminants virus (PPRV) of Indian origin (PPRV Jhansi 2003) initially adapted in Vero cells was further propagated in thermo-adapted (Ta) Vero cells grown at 40 °C for attaining thermo-adaption and attenuation of virus for development of Ta vaccine against PPR in goats and sheep. The virus was attenuated up to 50 passages in Ta Vero cells, at which, the virus was found sterile, innocuous in mice and guinea pigs and safe in seronegative goats and sheep. The developed vaccine was tested for its immunogenicity in goats and sheep by subcutaneous inoculation of 100 TCID50 (0.

Recombinant transferrin binding protein A (rTbpA) fragments of Pasteurella multocida serogroup B:2 provide variable protection following homologous challenge in mouse model.

Transferrin binding protein A (TbpA), an iron acquisition surface protein that also acts as virulence factor, is widely distributed among strains of Pasteurella multocida. In the present study, a total of seven clones of TbpA fragments (39D to F777; 39D to Q697; 188V to F777; 188V to Q697; 39D to P377; 188V to P377 and 39D to F187) belonging to P. multocida B:2 were constructed, over-expressed and purified as recombinant fusion proteins from Escherichia coli using affinity chromatography.

Draft Genome Sequence of Brucella abortus S99: Designated Antigenic Smooth Reference Strain Used in Diagnostic Tests in India.

Brucella abortus strain S99 is widely used for the preparation of colored, plain, recombinant and smooth lipopolysaccharide antigens for the preparation of Brucella diagnostic kits. The genome of this strain was sequenced and the length of the genome was 3,253,175 bp, with 57.2% G+C content.

Homogeneity of VacJ outer membrane lipoproteins among Pasteurella multocida strains and heterogeneity among members of Pasteurellaceae.

Outer membrane lipoproteins are widely distributed in Gram-negative bacteria which are involved in diverse mechanisms of physiology/pathogenesis. Various pathogenic bacterial strains belonging to the family-Pasteurellaceae have several surface exposed virulence factors including VacJ/VacJ-like lipoproteins. In the present study, vacJ gene encoding for VacJ outer membrane lipoprotein of different Pasteurella multocida strains (n = 10) were amplified, sequenced and compared with available VacJ/VacJ-like sequences (n = 45) of Pasteurellaceae members.