Mutation Pattern in the Genome of Neisseria gonorrhoeae and Its Association with Multidrug-resistant Isolates from Delhi, India

Bactericidal activity of esculetin is associated with impaired cell wall synthesis by targeting glutamate racemase of Neisseria gonorrhoeae

Neisseria gonorrhoeae (NG), the causative organism of gonorrhea, has been classified by the World Health Organization as 'Priority' two organism owing to its increased resistance to antibiotics and even failure of recommended dual therapy with ceftriaxone and azithromycin. As a result, the general and reproductive health of infected individuals is severely compromised. The imminent public health catastrophe of antimicrobial-resistant gonococci cannot be understated, as t he of severe complications and sequelae of infection are not only increasing but their treatment has also become more expensive. Tenacious attempts are underway to discover novel drug targets as well as new drugs to fight against NG. Therefore, a considerable number of phytochemicals have been tested for their remedial intercession via targeting bacterial proteins. The MurI gene encodes for an enzyme called glutamate racemase (MurI) that is primarily involved in peptidoglycan (PG) biosynthesis and is specific to the bacterial kingdom and hence can be exploited as a potential drug target for the treatment of bacterial diseases. Accordingly, diverse families of phytochemicals were screened in silico for their binding affinity with N. Gonorrhoeae MurI (NG-MurI) protein. Esculetin, one of the shortlisted compounds, was evaluated for its functional, structural, and anti-bacterial activity. Treatment with esculetin resulted in growth inhibition, cell wall damage, and altered permeability as revealed by fluorescence and electron microscopy. Furthermore, esculetin inhibited the racemization activity of recombinant, purified NG-MurI protein, one of the enzymes required for peptidoglycan biosynthesis. Our results suggest that esculetin could be further explored as a lead compound for developing new drug molecules against multidrug-resistant strains.

Multiple sexually transmitted co-infections are associated with adverse reproductive outcomes in asymptomatic adolescent pregnant women; A Prospective cohort study

Background

A prospective cohort was conducted to assess the prevalence of seven RTIs/STIs in adolescent asymptomatic pregnant women to find a significant correlation between infection and pregnancy.

Methods

The study was restricted to 18–19 years of asymptomatic adolescent pregnant women attending Ante-Natal Care and the health status of the pregnant women were followed up to parturition. The health status of the infant was followed till 6 months post-delivery. The prevalence of the concerning pathogens and the significance of their association with adverse outcomes of pregnancy were determined.

Results

Among 279 subjects, the most significant co-infections were observed for M. hominis with U. parvum (9.31%; p-value–0.0071/OR−2.6421) and U. urealyticum (7.88%; p-value–0.0119/OR−2.6455). Statistically significant associations were found between C. trachomatis [(p-value-0.0439); OR−2.9902] and M. genitalium [(p-value−0.0284); OR−3.442] with PTB, N. gonorrhoeae with LBW <2.5 kg [(p-value−0.0052);OR−4.9017], U. urealyticum with VLBW <2 kg [(p-value-0.0262);OR−3.0207], M. genitalium [(p-value-0.0184); OR−11.7976] and T. vaginalis with PROM [(p-value 0.0063); OR−19.4275] while M. genitalium [(p-value 0.0190); OR–12.9230] and U. urealyticum [(p-value 0.0063); OR-14.5149] with PPROM with 95% CI respectively.

Conclusions

Asymptomatic adolescents are at high risk of adverse pregnancy outcomes if infected with the concerned pathogens.

Molecular characterization of decreased susceptibility to ceftriaxone and genotyping of Neisseria gonorrheae isolates in New Delhi, India

Data on genetic characteristics of Neisseria gonorrhoeae isolates exhibiting decreased susceptibility to extended-spectrum cephalosporins in India is deficient. In this study, we have sequenced penA, porB, mtrR and ponA and bla_TEM genes in 70 clinical isolates of NG with varying ceftriaxone MICs. Amongst these, 22 (31.4%) were PPNG. Additionally, N. gonorrheae Multiantigen Sequence Typing was performed. Fisher exact and χ² were used to evaluate significance of mutations with MICs. A total of six non-mosaic penA (Penicillin binding protein 2 [PBP2]) amino acid patterns were seen (II, IV, IX, XII, XIX, XXII) of which, pattern IX was significantly associated with decreased susceptibility to ceftriaxone. Other significant associations were noted in porB & mtrR genes. There were no mutations in bla_TEM gene. ST6069 was significantly associated with decreased susceptibility to ceftriaxone. To conclude, development of decreased susceptibility to ceftriaxone in gonococci involves cumulation of different mutations in the four chromosomal genes investigated.

Genomic Characterization of Gonococci from Different Anatomic Sites, Italy, 2007-2014

In recent decades, Neisseria gonorrhoeae has developed resistance to several antimicrobial classes. Molecular epidemiology approaches are useful for detecting emerging, often resistant, gonococcal clones. In this study, 67 N. gonorrhoeae isolates from different anatomic sites, collected over 8 years in Italy, were analyzed by whole genome sequencing (WGS). WGS was performed using the Illumina NextSeq 500 platform. Phylogenetic analysis was based on core single nucleotide polymorphism (SNP) and core genome multilocus sequence typing (cgMLST). N. gonorrhoeae multi-antigen sequence typing (NG-MAST), MLST, and N. gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR) were carried out in silico using WGS data. Antimicrobial susceptibility against a four-drug panel was evaluated using a gradient diffusion method. Overall, gonococci clustered in accordance with NG-MAST, MLST, NG-STAR, and antimicrobials susceptibility profiles, but not with the site of isolation, HIV status, and patient sexual orientation. Phylogenetic analysis identified nine clades: two of them were the predominant and including gonococci of G1407 and G2400 genogroups.