Antimicrobial resistance to Neisseria gonorrhoeae in Canada: 2009-2013

Abstract

Background: Gonorrhea is on the rise in Canada. Treatment has been complicated by the fact that Neisseria gonorrhoeae has acquired resistance to many antibiotics, including penicillin, tetracycline, erythromycin and ciprofloxacin. The emergence of isolates with decreased susceptibilities to the third generation cephalosporins and reports of treatment failures in Canada and around the world are cause for concern.Objective: To assess the resistance levels of common antibiotics to N. gonorrhoeae and to observe trends in resistance and/or decreased susceptibility to ciprofloxacin, third generation cephalosporins and azithromycin.Methods: Laboratory surveillance data for N. gonorrhoeae isolates submitted by provincial microbiology laboratories to the National Microbiology Laboratory (NML) from 2009-2013 were compared. Results:Since 2009, there has been an overall rise in antibiotic-resistant N. gonorrhoeae. In 2013, 24.3% of the isolates were resistant to erythromycin, 18.9% were resistant to penicillin, 33.0% were resistant to tetracycline, and 29.3% were resistant to ciprofloxacin. The percentage of isolates with decreased susceptibility to ceftriaxone (≥0.125 mg/L) and/or cefixime (≥0.25 mg/L) was 3.9% in 2013. This number represents a decrease from 5.9% in 2012 and 7.6% in 2011. The proportion of azithromycin resistant (MIC ≥2 mg/L) N. gonorrhoeae isolates increased from 0.4% in 2009 to 1.2% in 2013. Conclusion:Resistance to erythromycin, penicillin, tetracycline and ciprofloxacin is common. Decreased susceptibility to ceftriaxone and/or cefixime is now almost 4% and azithromycin resistance is emerging but remains low at 1.2%. These results have informed the gonococcal infection treatment recommendations in the Canadian Guidelines on Sexually Transmitted Infections. Pen MIC ≥ 2.0 mg/L, Tet MIC ≥ 2.0 mg/L but ≤ 8.0 mg/L and Ery MIC ≥ 2.0 mg/L Probable CMRNG Probable Chromosomal Mediated Resistant N. gonorrhoeae One of the MIC values of Pen, Tet, Ery = 1 mg/L, the other two ≥ 2.0 mg/L TetR Tetracycline Resistant N. gonorrhoeae (chromosomal mediated) Tet MIC ≥ 2.0 mg/L but ≤ 8.0 mg/L CipR Ciprofloxacin Resistant N. gonorrhoeae Cip MIC ≥ 1.0 mg/L AzR Azithromycin Resistant N. gonorrhoeae Az MIC ≥ 2.0 mg/L SpecR Spectinomycin Resistant N. gonorrhoeae Spec R ≥ 128 mg/L CxDS N. gonorrhoeae with decreased susceptibility to Ceftriaxone Cx MIC ≥ 0.125 mg/L CeDS N. gonorrhoeae with decreased susceptibility to Cefixime Ce MIC ≥ 0.25 mg/L

Gonorrhea in Canada: 2003-2012

“…Antimicrobial resistance may also play a significant role in the increase in reported rates of gonorrhea, as the proportion of isolates resistant to a number of antibiotics has increased over time, (7) which may lead to treatment failure and a longer duration of infectiousness in affected patients. Emerging antimicrobial resistance in gonorrhea has led to changes in treatment recommendations across Canada and elsewhere (8,9,10,11).…”

Gonorrhea in Canada, 2010–2015

“…Gonococcal infections have recently shown resistance or decreased susceptibility to all of the antibiotics commonly used for treatment in Canada, including penicillins, tetracyclines, macrolides and quinolones (8,18). Antimicrobial resistance can lead to ineffective treatment and ongoing transmission of the uncured infection.…”

“…As in previous years, more cases were reported in males than females (at a ratio of 1:1.3), but the relative rate increase was greater among females (7). Moreover, the control and treatment of gonorrhea have become more complex due to the development of antimicrobial resistance in several countries, including Canada (8). The recent emergence of strains resistant to azithromycin and with decreased susceptibility to cephalosporins are threatening the last available treatment options (9).…”

Macrocyclic Complexes: A New Way Forward Into the Medicinal World.

“…After the revolution in the "golden era", when almost all groups of important antibiotics (tetracyclines, cephalosporins, aminoglycosides and macrolides) were discovered and the main problems of chemotherapy were solved in the1960s, the history repeats itself nowadays and these exciting compounds are in danger of losing their efficacy because of the increase in microbial resistance (Mayerset al, 2009). Currently, its impact is considerable with treatment failures associated with multidrug-resistant bacteria and it has become a global concern to public health (Martin et al, 2015).…”