27 research outputs found

    Assessment of spatio-temporal variations in surface water quality of Ghaggar River (North-Western, India) utilized for drinking and agricultural purposes

    Get PDF
    In the present study, statistical analyses (descriptive and principal component analysis) were applied to Ghaggar River surface water data set monitored in the month of June 2006 and 2007 to check spatio-temporal variations in water quality. From these, two summer observations were taken into consideration because in summer season, high concentrations are observed for different water constituents. The various physico-chemical constituents like pH, total dissolved solids (TDS), electrical conductivity (EC), temperature, Cl-, HCO3-, CO32-, Na+, K+, Ca2+, Mg2+, F-, SO42- and PO43- were analyzed. Statistical results revealed that water quality variables were totally different during the two summer observations.Keywords: Principal component analysis, spatio-temporal variations, water quality, summer season

    Molecular antimicrobial resistance surveillance for neisseria gonorrhoeae, Northern Territory, Australia

    Get PDF
    Neisseria gonorrhoeae antimicrobial resistance (AMR) is a globally recognized health threat; new strategies are needed to enhance AMR surveillance. The Northern Territory of Australia is unique in that 2 different first-line therapies, based primarily on geographic location, are used for gonorrhea treatment. We tested 1,629 N. gonorrhoeae nucleic acid amplification test–positive clinical samples, collected from regions where ceftriaxone plus azithromycin or amoxicillin plus azithromycin are recommended first-line treatments, by using 8 N. gonorrhoeae AMR PCR assays. We compared results with those from routine culture-based surveillance data. PCR data confirmed an absence of ceftriaxone resistance and a low level of azithromycin resistance (0.2%), and that penicillin resistance was \u3c5% in amoxicillin plus azithromycin regions. Rates of ciprofloxacin resistance and penicillinase-producing N. gonorrhoeae were lower when molecular methods were used. Molecular methods to detect N. gonorrhoeae AMR can increase the evidence base for treatment guidelines, particularly in settings where culture-based surveillance is limited

    Molecular Antimicrobial Resistance Surveillance for Neisseria gonorrhoeae, Northern Territory, Australia

    Get PDF
    Emerging Infectious Disease's an open access journal in the public domain. All content is freely available without charge to the user or his/her institution.Neisseria gonorrhoeae antimicrobial resistance (AMR) is a globally recognized health threat; new strategies are needed to enhance AMR surveillance. The Northern Territory of Australia is unique in that 2 different first-line therapies, based primarily on geographic location, are used for gonorrhea treatment. We tested 1,629 N. gonorrhoeae nucleic acid amplification test-positive clinical samples, collected from regions where ceftriaxone plus azithromycin or amoxicillin plus azithromycin are recommended first-line treatments, by using 8 N. gonorrhoeae AMR PCR assays. We compared results with those from routine culture-based surveillance data. PCR data confirmed an absence of ceftriaxone resistance and a low level of azithromycin resistance (0.2%), and that penicillin resistance was <5% in amoxicillin plus azithromycin regions. Rates of ciprofloxacin resistance and penicillinase-producing N. gonorrhoeae were lower when molecular methods were used. Molecular methods to detect N. gonorrhoeae AMR can increase the evidence base for treatment guidelines, particularly in settings where culture-based surveillance is limited

    Pharyngeal Gonorrhoea in Women: An Important Reservoir for Increasing Neisseria gonorrhoea Prevalence in Urban Australian Heterosexuals?

    Get PDF
    We aim to characterize sexual behavioral aspects of heterosexual Neisseria gonorrhoea (NG) acquisition in two Sexually Transmitted Diseases clinics in Sydney, Australia, in 2008–2012. Of 167 NG cases, 102 were heterosexually acquired with a trend of increasing NG prevalence in heterosexuals from 1.1% (95% CI 0.6–2.1) in 2008 to 3.0% (95% CI 2.0–4.0) in 2012 (P=0.027). Of heterosexual male cases, unprotected fellatio was the likely sexual activity for NG acquisition in 21/69 (30.4%) and commercial sex work (CSW) contact the likely source in 28/69 (40.6%). NG prevalence overall in CSW (2.2%) was not significantly higher than in non-CSW (1.2%) (P=0.15), but in 2012 there was a significant increase in NG prevalence in CSW (8.6%) compared to non-CSW (1.6%) (P<0.001). Pharyngeal NG was found in 9/33 (27.3%) female cases. Decreased susceptibility to ceftriaxone (MIC ≥ 0.03 mg/L) occurred in 2.5% NG isolates, none heterosexually acquired. All were azithromycin susceptible. A significant trend of increasing prevalence of heterosexual gonorrhoea in an urban Australian STD clinic setting is reported. We advocate maintenance of NG screening in women, including pharyngeal screening in all women with partner change who report fellatio, as pharyngeal NG may be an important reservoir for heterosexual transmission. Outreach to CSW should be enhanced

    Changes in the rates of Neisseria gonorrhoeae antimicrobial resistance are primarily driven by dynamic fluctuations in common gonococcal genotypes

    No full text
    Objectives: To examine how gonococcal genotypes and associated changes over time influence rates of Neisseria gonorrhoeae antimicrobial resistance

    Mixed gonococcal infections in a high-risk population, Sydney, Australia 2015: implications for antimicrobial resistance surveillance?

    No full text
    Objectives: Previous studies have shown that mixed-strain gonococcal infections can occur. However, it remains unclear whether such infections impact upon the reliability of Neisseria gonorrhoeae antimicrobial resistance (AMR) surveillance. In this study, we aimed to resolve this question by intensively sampling isolates from gonorrhoea- positive specimens in a high-risk population in Sydney, Australia. Methods: A total of 615 N. gonorrhoeae isolates, originating from 63 clinical samples (31 rectal swabs and 32 throat swabs), were characterized. All isolates were subject to N. gonorrhoeae identification, antimicrobial susceptibility testing and genotyping by SNP-based MLST. Results: Only 2 of the 63 (3.2%) samples provided evidence of mixed-strain infections. These comprised two rectal swabs that harboured isolates of different SNP-based MLST genotypes; however, the AMR susceptibility profiles of the different genotypes from these samples were indistinguishable. Within-sample differences in the AMR susceptibility profiles were observed for a further seven samples; however, the differences were not considered significant; MIC values were typically within a 2-fold difference or were close to test breakpoints. Conclusions: Results of this study provide further evidence that mixed-strain gonococcal infections do occur, although at low prevalence. Our data indicate that at a population level such infections are unlikely to impact significantly upon N. gonorrhoeae AMR surveillance

    A real-time PCR assay for direct characterization of the Neisseria gonorrhoeae GyrA 91 locus associated with ciprofloxacin susceptibility

    No full text
    Objectives: The objective of this study was to develop a real-time PCR method for specific detection of the gonococcal GyrA amino acid 91 locus directly in clinical samples so as to predict Neisseria gonorrhoeae ciprofloxacin susceptibility. Methods: The real-time PCR assay, GyrA91-PCR, was designed using two probes, one for detection of the WT S91 sequence and the other for detection of the S91F alteration. The performance of the assay was initially assessed using characterized N. gonorrhoeae isolates (n = 70), a panel of commensal Neisseria and Moraxella species (n = 55 isolates) and clinical samples providing negative results by a commercial N. gonorrhoeae nucleic acid amplification test (NAAT) method (n = 171). The GyrA91-PCR was then applied directly to N. gonorrhoeae NAAT-positive clinical samples (n = 210) from the year 2014 for which corresponding N. gonorrhoeae isolates with susceptibility results were also available. Results: The GyrA91-PCR accurately characterized the GyrA 91 locus of all 70 N. gonorrhoeae isolates (sensitivity = 100%, 95% CI = 94.9%-100%), whereas all non-gonococcal isolates and N. gonorrhoeae NAAT-negative clinical samples gave negative results by the GyrA91-PCR (specificity = 100%, 95% CI = 98.4%-100%). When applied to the 210 N. gonorrhoeae NAAT-positive clinical samples, the GyrA91-PCR successfully characterized 195 samples (92.9%, 95% CI = 88.5%-95.9%). When compared with the corresponding bacterial culture results, positivity by the GyrA91-PCR WT probe correctly predicted N. gonorrhoeae susceptibility to ciprofloxacin in 161 of 162 (99.4%, 95% CI = 96.6%-99.9%) samples. Conclusions: The use of a PCR assay for detection of mutation in gyrA applied directly to clinical samples can predict ciprofloxacin susceptibility in N. gonorrhoeae

    Azithromycin-resistant Neisseria gonorrhoeae spreading amongst men who have sex with men (MSM) and heterosexuals in New South Wales, Australia, 2017

    No full text
    To identify the genetic basis of resistance as well as to better understand the epidemiology of a recent surge in azithromycin-resistant Neisseria gonorrhoeae in New South Wales, Australia.Azithromycin-resistant N. gonorrhoeae isolates (n = 118) collected from 107 males, 10 females and 1 transsexual between January and July 2017 were genotyped using a previously described iPLEX method. The results were compared with phenotypic resistance profiles and available patient data.The iPLEX results revealed 10 different N. gonorrhoeae genotypes (designated AZI-G1 to AZI-G10) of which three were responsible for the majority of infections; AZI-G10 (74.6%, 88 isolates; 87 males and 1 transsexual), AZI-G4 (11.0%, 13 isolates; 7 males and 6 females) and AZI-G7 (6.8%, 8 isolates; 7 males and 1 female). The observed resistance was attributable to one of two different azithromycin resistance mechanisms; the 23S rRNA C2611T mutation was identified in 24% of isolates, whereas the majority of resistance (76%) was associated with a meningococcal-type mtrR variant. Additionally, one isolate was found to harbour both the 23S rRNA C2611T mutation and a type XXXIV mosaic penA sequence associated with cephalosporin resistance.These data indicate outbreaks of azithromycin-resistant gonococci amongst networks of MSM and heterosexuals in New South Wales. The results also provide further evidence that azithromycin may soon be an ineffective treatment option for gonococcal infection and highlight the urgent need to explore alternative therapies

    Real-time PCR detection of Neisseria gonorrhoeae susceptibility to penicillin.

    No full text
    The objective of this study was to develop a real-time PCR assay targeting the gonococcal porB gene (PorB-PCR) for predicting susceptibility of Neisseria gonorrhoeae to penicillin. This complements a previously described PCR assay for detecting penicillinase-producing N. gonorrhoeae (PPNG) developed by our laboratory (PPNG-PCR). The PorB-PCR assay was designed using six probes to characterize various combinations of amino acids at positions 101 and 102 of the PorB1b class protein, including the WT G101/A102 and mutant G101K/A102D, G101K/A102N and G101K/A102G sequences, as well as the PorB1a sequence. The ability of these sequences to predict penicillin susceptibility was initially assessed using 2307 N. gonorrhoeae isolates from throughout Australia for which phenotypic susceptibility data were available. The assay was then applied to N. gonorrhoeae-positive clinical specimens (n?=?70). Specificity was assessed by testing commensal Neisseria strains (n?=?75) and N. gonorrhoeae-negative clinical specimens (n?=?171). Testing of the 2307 N. gonorrhoeae isolates using PorB-PCR to detect G101/A102 and PorB1a sequences identified a total of 78.4% (61.2% and 17.2%, respectively) of penicillin-susceptible isolates with specificities of 97.4% and 99.3% and positive predictive values of 98.8% and 98.9%, where PPNG strains were simultaneously identified and excluded. Similar performance data were obtained when the PorB-PCR assay was applied to the N. gonorrhoeae-positive clinical specimens. No false-positive results were observed for the N. gonorrhoeae-negative samples and no cross-reactions were observed with the non-gonococcal species. When used in parallel with the previously described PPNG-PCR, the PorB-PCR approach has the potential to facilitate individualized treatment of gonorrhoea using penicillin
    corecore