Antimicrobial resistance to Neisseria gonorrhoeae in Canada: 2009-2013

The Assessment of Antimicrobial and Anti-Biofilm Activity of Essential Oils against Staphylococcus aureus Strains

The increase in antimicrobial resistance and tolerance over the years has become a serious public health problem, leading to the inevitable development of alternative antimicrobial agents as substitutes for industrial pharmaceutical antibiotics targeting humans and animals under the concept of one health. Essential oils (EOs) extracted from aromatic and pharmaceutical plants incorporate several bioactive compounds (phytochemicals) that positively affect human and animal health. Herein, this work aimed to examine a standardized chemical composition and screen the antimicrobial and anti-biofilm activity of Thymus sibthorpii, Origanum vulgare, Salvia fruticosa, and Crithmum maritimum EOs against three different Staphylococcus aureus strains by gold-standard disc diffusion, broth microdilution, and microtiter plate biofilm assays. Therefore, the evaluation of the above-mentioned EOs were considered as substitutes for antibiotics to combat the ever-mounting antimicrobial resistance problem. The observed bacterial growth inhibition varied significantly depending on the type and concentration of the antimicrobials. Thymus sibthorpii was determined as the strongest antimicrobial, with 0.091 mg/mL minimum inhibitory concentration (MIC) and a 14-33 mm diameter inhibition zone at 5% (v/v) concentration. All tested EOs indicated almost 95% inhibition of biofilm formation at their half MIC, while gentamicin sulfate did not show sufficient anti-biofilm activity. None of the methicillin-resistant strains showed resistance to the EOs compared to methicillin-sensitive strains. Thymus sibthorpii and Origanum vulgare could be potential alternatives as antimicrobial agents to overcome the problem of microbial resistance. The tested EOs might be incorporated into antimicrobial products as safe and potent antimicrobial and anti-biofilm agents.

Effect of (+) usnic Acid on Pigment Production in Bacteria

Antibiotic resistance is a universal problem in bacterial infections. Hence it gives high priority for new therapeutic methods to alternate conventional antibiotic treatment. Pigment production is one of the virulence characteristics of bacteria regulated by a quorum-sensing mechanism. Antiquorum sensing activities will not directly affect the viability of bacteria; however, they will reduce the pathogenicity of bacteria. Thereby it gives an adverse probability of the development of drug resistance. Aim of our study is to evaluate the activity of (+) usnic acid on pigment production in Pseudomonas aeruginosa MTCC 2453, Chromobacterium violaceum MTCC 2656 and Serratia marcescens MTCC 8708. (+) usnic acid eluted by column chromatography. Dimethyl sulphoxide (DMSO) was used as the solvent for (+) usnic acid. Antibacterial activity determined by Agar well diffusion and broth microdilution methods. Effect on pigment production was assessed by spectroscopy. (+) usnic acid showed accumulative inhibition as its concentration increases on pigment production by Pseudomonas aeruginosa MTCC 2453, Chromobacterium violaceum MTCC 2656 and Serratia marcescens MTCC 8708. The lowest concentrations of (+) usnic acid manifested 50% inhibition of pigment production was 122.67, 87.73 and 205.26 µg/ml respectively on above mentioned order in bacteria. The concentration of (+) usnic acid that showed pigment production inhibition did not hinder the growth of the bacteria, but it can reduce the virulence of the bacteria. This property can be used to resolve the drug resistance in bacteria. Further studies are required to check the action of (+) usnic acid on other virulence factors of the bacteria to prove the quorum quenching activity.

Photorhabdus sp. ETL Antimicrobial Properties and Characterization of Its Secondary Metabolites by Gas Chromatography-Mass Spectrometry

Entomopathogenic nematodes (EPNs) are known to be highly pathogenic to insect pests, due to their associated symbiotic bacteria, which produce virulence factors, exo-enzymes and other harmful secondary metabolites to conquer, kill, and degrade their insect hosts. However, these properties are not fully characterized. This study reports on the antimicrobial activities of Photorhabdus sp. strain ETL, symbiotically associated to an insect pathogenic nematode, Heterorhabditis zealandica, against human pathogenic bacteria and toxigenic fungi, as well as the non-targeted profiling of its secondary metabolites (SMs) using gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Fatty acids including 3-eicosene, (E)-; 5-eicosene, (E)-; eicosene; 9-octadecenamide; undecanoic acid with shown antimicrobial activities were detected. This provided more insight on the composition and bioactivities of SMs produced by the Photorhabdus sp.

A study of Ophthalmia Neonatorum in the Central Reion of Ghana: Causative Agents and Antibiotic Susceptibility Patterns

In developing countries such as Ghana, ophthalmia neonatorum (ON) remains a public health concern. This is because of its unknown etiology patterns, the growing concerns of antibiotic resistance strains and the contribution of ON to childhood blindness. This study was therefore conducted to determine the causative agents, risk factors and the antibiotic sensitivity patterns of micro-organisms associated with ON. A clinic-based prospective study was conducted in the Maternal and Child Health units of 6 health care facilities in the Central region of Ghana over a period of 17 months. Conjunctival swabs were taken from all neonates with clinical signs of ON. Isolation and characterization of bacteria were done using standard microbiological methods. Additionally, data were collected and analyzed on neonate's demographics and clinical features of ON. Microbial growth was recorded in 86 cases (52.4%) out of the 110 neonates assessed. Staphylococcus spp. (39.2% of all positive cultures) was the most common causative organism. No case of gonococcus was isolated. Delivery method, vaginal discharge, administration of prophylaxis and weight of neonate were the risk factors associated with the development of ON (P < .05). The level of resistance to Tetracycline was found to be 73%. Neonatal conjunctivitis is more likely to be acquired postnatal. Culture and sensitivity testing are required as an important guide for treatment. The commonest causative organism, Staphylococcus spp., were found to be resistant to Teteracyline, therefore is the need to consider alternatives measures in the prevention and control of ON.

Interventions for preventing ophthalmia neonatorum

BACKGROUND

Ophthalmia neonatorum is an infection of the eyes in newborns that can lead to blindness, particularly if the infection is caused by Neisseria gonorrhoeae. Antiseptic or antibiotic medication is dispensed into the eyes of newborns, or dispensed systemically, soon after delivery to prevent neonatal conjunctivitis and potential vision impairment.

OBJECTIVES

1. To determine if any type of systemic or topical eye medication is better than placebo or no prophylaxis in preventing ophthalmia neonatorum. 2. To determine if any one systemic or topical eye medication is better than any other medication in preventing ophthalmia neonatorum.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, and three trials registers, date of last search 4 October 2019. We also searched references of included studies and contacted pharmaceutical companies.  SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials of any topical, systemic, or combination medical interventions used to prevent ophthalmia neonatorum in newborns compared with placebo, no prophylaxis, or with each other.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by Cochrane. Outcomes were: blindness or any adverse visual outcome at 12 months, conjunctivitis at 1 month (gonococcal (GC), chlamydial (CC), bacterial (BC), any aetiology (ACAE), or unknown aetiology (CUE)), and adverse effects.  MAIN RESULTS: We included 30 trials with a total of 79,198 neonates. Eighteen studies were conducted in high-income settings (the USA, Europe, Israel, Canada), and 12 were conducted in low- and middle-income settings (Africa, Iran, China, Indonesia, Mexico). Fifteen of the 30 studies were quasi-randomised. We judged every study to be at high risk of bias in at least one domain. Ten studies included a comparison arm with no prophylaxis. There were 14 different prophylactic regimens and 12 different medications in the 30 included studies. Any prophylaxis compared to no prophylaxis  Unless otherwise indicated, the following evidence comes from studies assessing one or more of the following interventions: tetracycline 1%, erythromycin 0.5%, povidone-iodine 2.5%, silver nitrate 1%. None of the studies reported data on the primary outcomes: blindness or any adverse visual outcome at any time point. There was only very low-certainty evidence on the risk of GC with prophylaxis (4/5340 newborns) compared to no prophylaxis (5/2889) at one month (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.24 to 2.65, 3 studies). Low-certainty evidence suggested there may be little or no difference in effect on CC (RR 0.96, 95% CI 0.57 to 1.61, 4874 newborns, 2 studies) and BC (RR 0.84, 95% CI 0.37 to 1.93, 3685 newborns, 2 studies). Moderate-certainty evidence suggested a probable reduction in risk of ACAE at one month (RR 0.65, 95% 0.54 to 0.78, 9666 newborns, 8 studies assessing tetracycline 1%, erythromycin 0.5%, povidone-iodine 2.5%, silver nitrate 1%, colostrum, bacitracin-phenacaine ointment). There was only very low-certainty evidence on CUE  (RR 1.75, 95% CI 0.37 to 8.28, 330 newborns, 1 study). Very low-certainty evidence on adverse effects suggested no increased nasolacrimal duct obstruction (RR 0.93, 95% CI 0.68 to 1.28, 404 newborns, 1 study of erythromycin 0.5% and silver nitrate 1%) and no increased keratitis (single study of 40 newborns assessing silver nitrate 1% with no events).    Any prophylaxis compared to another prophylaxis Overall, evidence comparing different interventions did not suggest any consistently superior intervention. However, most of this evidence was of low-certainty and was extremely limited.

AUTHORS' CONCLUSIONS

There are no data on whether prophylaxis for ophthalmia neonatorum prevents serious outcomes such as blindness or any adverse visual outcome. Moderate-certainty evidence suggests that the use of prophylaxis may lead to a reduction in the incidence of ACAE in newborns but the evidence for effect on GC, CC or BC was less certain. Comparison of individual interventions did not suggest any consistently superior intervention, but data were limited. A trial comparing tetracycline, povidone-iodine (single administration), and chloramphenicol for GC and CC could potentially provide the community with an effective, universally applicable prophylaxis against ophthalmia neonatorum.

Identification of Novel Bioactive Compound Derived from Rheum officinalis against Campylobacter jejuni NCTC11168

Gastric diseases are increasing with the infection of Campylobacter jejuni. Late stages of infection lead to peptic ulcer and gastric carcinoma. C. jejuni infects people within different stages of their life, especially childhood, causing severe diarrhea; it infects around two-thirds of the world population. Due to bacterial resistance against standard antibiotic, a new strategy is needed to impede Campylobacter infections. Plants provide highly varied structures with antimicrobial use which are unlikely to be synthesized in laboratories. A special feature of higher plants is their ability to produce a great number of organic chemicals of high structural diversity, the so-called secondary metabolites. Twenty plants were screened to detect their antibacterial activities. Screening results showed that Rheum officinalis was the most efficient against C. jejuni. Fractionation pattern was obtained by column chromatography, while the purity test was done by thin-layer chromatography (TLC). The chemical composition of bioactive compound was characterized using GC-MS, nuclear magnetic resonance, and infrared analysis. Minimal inhibitory concentration (MIC) of the purified compound was 31.25 µg/ml. Cytotoxicity assay on Vero cells was evaluated to be 497 µg/ml. Furthermore, the purified bioactive compound activated human lymphocytes in vitro. The data presented here show that Rheum officinalis could potentially be used in modern applications aimed at the treatment or prevention of foodborne diseases.

Mechanistic Pathways for Peptidoglycan O-Acetylation and De-O-Acetylation

The post-synthetic O-acetylation of the essential component of bacterial cell walls, peptidoglycan (PG), is performed by many pathogenic bacteria to help them evade the lytic action of innate immunity responses. Occurring at the C-6 hydroxyl of N-acetylmuramoyl residues, this modification to the glycan backbone of PG sterically blocks the activity of lysozymes. As such, the enzyme responsible for this modification in Gram-positive bacteria is recognized as a virulence factor. With Gram-negative bacteria, the O-acetylation of PG provides a means of control of their autolysins at the substrate level. In this review, we discuss the pathways for PG O-acetylation and de-O-acetylation and the structure and function relationship of the O-acetyltransferases and O-acetylesterases that catalyze these reactions. The current understanding of their mechanisms of action is presented and the prospects of targeting these systems for the development of novel therapeutics are explored.

Gonorrhea in Canada, 2010-2015

Background

Gonorrhea is the second most commonly reported sexually transmitted infection (STI) in Canada after chlamydia, and rates for this STI have been increasing since 1997.

Objective

To summarize trends observed in gonorrhea rates for 2010-2015 in Canada.

Methods

Laboratory-confirmed cases of gonorrhea are reported to the Public Health Agency of Canada (PHAC) by all of the Canadian provinces and territories. The overall national rate was computed, as were rates per sex, age group and province/territory.

Results

In 2015, 19,845 cases of gonorrhea were reported in Canada, corresponding to a rate of 55.4 cases per 100,000 population and a 65.4% increase from 2010 (33.5 cases per 100,000 population). Males had consistently higher rates than did females (70.2 per 100,000 versus 40.6 per 100,000 in 2015) and faster rising rates (85.2% versus 39.5% in 2010-2015). Rates among adults 60 years and older increased faster than rates among younger people, although the highest rates were among those 15-29 years of age. The Northwest Territories, Nunavut and Yukon had the highest gonorrhea rates in 2015.

Conclusion

Males, adolescents and young adults continue to represent the majority of gonorrhea cases. Research is needed to better understand the current trends in gonorrhea infection in order to maintain, evaluate and improve primary and secondary STI prevention activities.

What are Canadian primary care physicians prescribing for the treatment of gonorrhea?

BACKGROUND

Cases of Neisseria gonorrhea are on the rise in Canada, which-if undetected or undertreated-can lead to morbidity and infertility. In addition, the number of antimicrobial resistant strains is also increasing creating the risk that N. gonorrhea may become untreatable. In 2013, the Public Health Agency of Canada (PHAC) released Canadian recommendations for the management and treatment of gonorrhea that identified the need for combination therapy to address and minimize antimicrobial resistance. However, the level of awareness and uptake of these guidelines is not well-known.

OBJECTIVES

To assess primary care physicians' prescribing practices for the management and treatment of gonorrhea.

METHODS

After validity testing, two online cross-sectional surveys were conducted with a convenience sample of Canadian physicians. Physicians answered true/false statements and open-ended questions relating to three clinical scenarios: 1) suspected anogenital infection drawing from a population of men who have sex with men (MSM); 2) suspected anogenital infection drawing from a non-MSM population; and, 3) suspected pharyngeal infection drawing from any population. Frequencies of responses were calculated for the statements. Open-ended responses were recoded into treatment categories and frequencies were calculated for each scenario.

RESULTS

A total of 625 physicians completed the survey. Most physicians (60%-95%) accurately identified knowledge statements regarding pharmaceutical management, partner notification and public health reporting. For all clinical scenarios, 30%-35% of physicians did not provide any treatment information, approximately 30% indicated treating with cephalosporin monotherapy, 20%-25% indicated they would prescribe a cephalosporin and azithromycin and a minority of physicians identified other treatment options. When physicians were asked about the purpose of the second antibiotic, azithromycin, 49% indicated it was to provide presumptive treatment for gonorrhea and chlamydia. Forty-one percent indicated it was to provide presumptive treatment for chlamydia only.

CONCLUSION

This convenience sample suggests that although knowledge of pharmaceutical management, partner notification, and public health reporting is high, the use of combination therapy to deter the development of antimicrobial resistant gonorrhea may not be widespread among primary care physicians. In light of both the growing incidence of N. gonorrhea and the rising rates of antimicrobial resistance in Canada, consideration on how to improve awareness and update of best prescribing practices in primary care may be indicated.

Methods for in vitro evaluating antimicrobial activity: A review

In recent years, there has been a growing interest in researching and developing new antimicrobial agents from various sources to combat microbial resistance. Therefore, a greater attention has been paid to antimicrobial activity screening and evaluating methods. Several bioassays such as disk-diffusion, well diffusion and broth or agar dilution are well known and commonly used, but others such as flow cytofluorometric and bioluminescent methods are not widely used because they require specified equipment and further evaluation for reproducibility and standardization, even if they can provide rapid results of the antimicrobial agent's effects and a better understanding of their impact on the viability and cell damage inflicted to the tested microorganism. In this review article, an exhaustive list of in vitro antimicrobial susceptibility testing methods and detailed information on their advantages and limitations are reported.

Is the tide turning again for cephalosporin resistance in Neisseria gonorrhoeae in Europe? Results from the 2013 European surveillance

BACKGROUND

The emerging resistance to the extended-spectrum cephalosporins (ESCs) in Neisseria gonorrhoeae together with increasing incidence of gonorrhoea cases in many countries have been global public health concerns. However, in recent years the levels of ESC resistance have decreased in several regions worldwide. We describe the European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP) data from 2013, and compare them to corresponding data from 2009-2012.

METHODS

During 2013, N. gonorrhoeae isolates from 21 participating countries were examined. Antimicrobial susceptibility testing (Etest or agar dilution) was performed for cefixime, ceftriaxone, ciprofloxacin, azithromycin, spectinomycin and gentamicin. Statistical analyses were performed to identify significant changes in resistance between years and to investigate associations between patients with resistant gonococcal isolates and collected epidemiological variables.

RESULTS

In total, 93 (4.7 %) of 1994 isolates displayed resistance to cefixime, representing an increase compared to the 3.9 % detected in 2012 (p = 0.23). Cefixime resistance was detected in 13 (61.9 %) of the 21 countries. Cefixime resistance among men who have sex with men was only 1.2 %, compared to 5.6 % and 6.1 % in females and male heterosexuals, respectively. The univariate analysis confirmed that isolates resistant to cefixime were more likely to be from females (OR 4.87, p < 0.01) or male heterosexuals (OR 5.32, p < 0.01). Seven (0.4 %) isolates displayed ceftriaxone resistance (in addition to cefixime resistance) compared to three and 10 isolates in 2012 and 2011, respectively. All 93 isolates with cefixime resistance were additionally resistant to ciprofloxacin and 16 (17.2 %) were also resistant to azithromycin. Among all tested isolates (n = 1994), the ciprofloxacin resistance level (52.9 %) was higher than in 2012 (50.1 %; p = 0.08), and azithromycin resistance (5.4 %) increased since 2012 (4.5 %; p = 0.16).

CONCLUSIONS

In 2013, the ESC resistance was again slightly increasing in Europe. This emphasises the importance of implementing the actions outlined in the European and additional response plans, particularly activities strengthening the surveillance of antimicrobial resistance. Ceftriaxone combined with azithromycin remains a satisfactory option for the first-line treatment of gonorrhoea. However novel antimicrobials (new derivatives of previously developed antimicrobials or newly developed antimicrobials) for effective monotherapy or at least inclusion in new dual antimicrobial therapy regimens (combined with previously developed antimicrobials or novel antimicrobials) will likely be required.

Gonorrhea in Canada: 2003-2012

BACKGROUND

Gonorrhea is the second most commonly reported sexually transmitted infection in Canada. Between 1991 and 1997, Canada experienced a sharp decline in the rates of reported cases of gonorrhea, followed by a steady incline.

OBJECTIVE

To identify trends in reported cases of gonorrhea in Canada from January 1, 2003 to December 31, 2012.

METHODS

Notifiable disease reports were submitted to the Public Health Agency of Canada by provincial and territorial epidemiological units and data were summarized by age and sex.

RESULTS

Between 2003 and 2012, the rate of reported cases of gonorrhea increased by 38.9%, from 26.0 to 36.2 per 100,000. Over this time frame, a greater relative rate increase was observed in females, though rates of gonorrhea increased in both sexes and across all age groups. In 2012, as in previous years, the rate of reported cases of gonorrhea was higher in males than females (41.4 vs. 31.0 per 100,000). Females between the ages of 15 and 24 years and males between the ages of 20 and 29 years accounted for the highest rates of gonorrhea in 2012.

CONCLUSION

In Canada, as in many countries, gonorrhea is on the rise, especially in young adults. This increase in rates of reported cases is in part due to improved diagnosis through nucleic acid amplification (NAAT) testing and may also be affected by growing gonococcal resistance to many available treatments.