Antibiotic susceptibility of Neisseria gonorrhoeae isolates from Guangzhou, China, during 2002-2011

Drug resistance of pathogens causing nosocomial infection in orthopedics from 2012 to 2017: a 6-year retrospective study

Background

Hospital-acquired infections (HAIs) are an emerging global problem that increases in-hospital mortality, length of stay, and cost. We performed a 6-year retrospective study to provide valuable insight into appropriate antibiotic use in HAI cases. We also aimed to understand how hospitals could reduce pathogen drug resistance in a population that overuses antibiotics.

Methods

All data (2012–2017) were obtained from the hospital information warehouse and clinical microbiology laboratory.

Results

We isolated 1392 pathogen strains from patients admitted to the orthopedics department during 2012–2017. Escherichia coli (14.7%, 204/1392), Enterobacter cloacae (13.9%, 193/1392), and Staphylococcus aureus (11.3%, 157/1392) were the most common pathogens causing nosocomial infections. The dominant Gram-negative bacterium was E. coli, with high resistance to ampicillin, levofloxacin, cotrimoxazole, gentamicin, and ciprofloxacin, in that order. E. coli was least resistant to amikacin, cefoperazone-sulbactam. The most dominant Gram-positive bacterium was S. aureus, highly resistant to penicillin and ampicillin, but not resistant to fluoroquinolones and cotrimoxazole. Analysis of risk factors related to multidrug-resistant bacteria showed that patients with open fractures (Gustillo III B and IIIC) were significantly more susceptible to methicillin-resistant S. aureus infections (p < 0.05). Additionally, extended-spectrum β-lactamase-producing E. coli infections occurred significantly more often in patients with degenerative diseases (p < 0.05). Elderly patients tended to be more susceptible to multidrug-resistant bacterial infections, but this outcome was not statistically significant.

Conclusions

Antimicrobial resistance is a serious problem in orthopedics. To effectively control antimicrobial resistance among pathogens, we advocate extensive and dynamic monitoring of MDR bacteria, coupled with careful use of antibiotics.

Changing antimicrobial susceptibility and molecular characterisation of Neisseria gonorrhoeae isolates in Guangdong, China: in a background of rapidly rising epidemic

The prevalence of Neisseria gonorrhoeae infections has increased rapidly since 2015 in China. Antimicrobial resistance and molecular mobilisation in N. gonorrhoeae are two important factors driving this increasing prevalence. This study explored changes in antimicrobial susceptibility and molecular characteristics of N. gonorrhoeae collected in Guangdong, China (2013-2017). A total of 704 isolates were collected in two cities in Guangdong. MICs of major antimicrobials were determined. Penicillinase-producing N. gonorrhoeae (PPNG) and tetracycline-resistant N. gonorrhoeae (TRNG) were characterised, and N. gonorrhoeae multiantigen sequence typing (NG-MAST) was performed. High resistance to penicillin (68.2%), tetracycline (85.7%) and ciprofloxacin (98.2%) was observed. Spectinomycin, ceftriaxone and azithromycin appeared effective, with susceptibilities of 100%, 96.4% and 90.7%, respectively. Resistance to penicillin decreased significantly from 78.4% to 73.6% and to azithromycin from 11.9% to 3.7%. Total prevalence of PPNG, TRNG and PPNG/TRNG was 25.4%, 33.1% and 13.4%, respectively. Rates of PPNG decreased significantly from 37.3% to 23.9%, TRNG from 50.0% to 31.3%, and PPNG/TRNG from 23.5% to 11.7%. However, the ratio of African-type PPNG increased significantly (18.4% to 64.1%) compared with decreasing Asian-type PPNG (81.6% to 33.3%), and the ratio of American-type TRNG increased significantly (0% to 13.7%) compared with decreasing Dutch-type TRNG (100% to 86.3%). A total of 271 sequence types (STs) were identified by NG-MAST from 380 isolates collected in 2013, 2014 and 2017, with 145 novel STs. African-type PPNG is increasing and replacing Asian-type, and novel STs have emerged. Gonococcal isolates with new genotypes might contribute to the rising gonorrhoea epidemic in this area.

Systematic review and survey of Neisseria gonorrhoeae ceftriaxone and azithromycin susceptibility data in the Asia Pacific, 2011 to 2016

BACKGROUND

Antimicrobial resistance in Neisseria gonorrhoeae is a global concern, with the ongoing emergence of ceftriaxone and azithromycin resistance threatening current treatment paradigms. To monitor the emergence of antimicrobial resistance in N. gonorrhoeae, the World Health Organization (WHO) Gonococcal Antimicrobial Surveillance Programme (GASP) has operated in the Western Pacific and South East Asian regions since 1992. The true burden of antimicrobial resistance remains unknown. In response, the objective of this study was to survey ceftriaxone and azithromycin susceptibility in N. gonorrhoeae across the western Pacific and south-east Asia, and interlink this data with systematically reviewed reports of ceftriaxone and azithromycin resistance.

METHODS AND FINDINGS

The WHO Collaborating Centre for Sexually Transmitted Infections and Antimicrobial Resistance, Sydney, coordinated annual surveys of gonococcal susceptibilities with participating laboratories, and additionally undertook a systematic review of reports detailing gonococcal ceftriaxone and azithromycin susceptibility data for locations geographically in the Asia Pacific from 2011 to 2016. It was found that surveillance of gonococcal antimicrobial resistance remains limited in the Asia Pacific, with weaker surveillance of azithromycin versus ceftriaxone. Ninety-three published reports were identified (including national reports) which documented susceptibility data for ceftriaxone and azithromycin. GASP survey data was available for 21 countries, territories or areas, and suggested MICs are increasing for ceftriaxone and azithromycin. Between 2011 and 2016, the percentage of locations reporting >5% of gonococcal isolates with MICs to ceftriaxone meeting WHO's definition of decreased susceptibility (MIC ≥ 0.125 mg/L) increased from 14.3% to 35.3% and the percentage of locations reporting >5% of gonococcal isolates with azithromycin resistance (MIC ≥ 1 mg/L) increased from 14.3% to 38.9%. Published reports were available for several countries that did not provide GASP surveillance responses for ceftriaxone (n = 5) and azithromycin (n = 3) respectively. Over the study period, there was a 183% increase in the number of countries providing surveillance data for GASP for both ceftriaxone and azithromycin, and a 30.6% increase in ceftriaxone MIC testing across the Asia Pacific facilitated by this project.

CONCLUSION

This study provides the first comprehensive illustration of increasing MICs to ceftriaxone in the Asia Pacific. The survey and literature review additionally detail increasing resistance to azithromycin. Further surveillance system strengthening is required to monitor these trends in order to address and curb gonococcal AMR in the region.

Determining the in vitro susceptibility of Neisseria gonorrhoeae isolates from 8 cities in Guangdong Province through an improved microdilution method

A microdilution method for the antibiotic susceptibility testing of Neisseria gonorrhoeae was established and improved, and the antibiotic resistance of N. gonorrhoeae samples isolated from 8 cities of Guangdong in 2016 was determined. The improved microdilution method was compared with the agar dilution method recommend by the World Health Organization (WHO) Western Pacific Region by testing the susceptibility of 100 clinical N. gonorrhoeae isolates. The essential agreement (EA), categorical agreement (CA), very major error (VME), major error (ME), and minor error (MIE) levels of the two methods were analyzed; the acceptable performance rates were measured as follows: ≥90% for EA or CA, ≤3% for VME or ME, and ≤7% for MIE. The EA, CA, VME, ME, and MIE of each method for 7 antibiotics, penicillin, tetracycline, ciprofloxacin, spectinomycin, ceftriaxone, cefixime, and azithromycin, were 96%-100%, 94%-100%, 0%-3%, 0%-2%, and 0%-6%, respectively. The Wilcoxon signed-rank test results indicated 94%-100% agreement between the 2 methods after excluding off-scale values (P > 0.05). The susceptibility of 634 N. gonorrhoeae strains to the 7 antibiotics above were tested through the microdilution method. The resistant rates of the isolates against ciprofloxacin, tetracycline, penicillin, and azithromycin were 99.8%, 88.3%, 53.8%, and 11%, and the percentages of the isolates with decreased susceptibility to ceftriaxone (minimum inhibitory concentration [MIC] ≥0.125 μg/mL) and cefixime (MIC ≥0.25 μg/mL) were 2.1% and 12%, respectively, in Guangdong. Among 8 cities, Shenzhen had the highest rates of resistance against penicillin (77.8%) and decreased susceptibility against ceftriaxone (5.6%). Zhuhai had the highest rates of decreased susceptibility against cefixime (30.1%), and Jiangmen had the highest azithromycin-resistant isolates (16.8%). The findings from this study indicated that the improved microdilution method is an alternative for testing the antimicrobial susceptibility of N. gonorrhoeae. The resistance rates of N. gonorrhoeae against penicillin, tetracycline, and ciprofloxacin were high. While ceftriaxone, cefixime, and spectinomycin remained effective against N. gonorrhoeae, their effectiveness seemed to be decreasing over time. Azithromycin therapy requires timely susceptibility test results.

Surveillance of the Antimicrobial Susceptibility of Neisseria gonorrhoeae Isolates Collected in Changsha, China from 2003 to 2015

A total of 1,294 Neisseria gonorrhoeae isolates obtained in Changsha, China from 2003 to 2015 were examined for their susceptibility to penicillin (PEN), ciprofloxacin (CIP), spectinomycin (SPT), and ceftriaxone (CRO) using the disc diffusion method. In addition, the minimum inhibitory concentrations (MICs) of CRO for 460 isolates collected during 2008-2015 was determined by agar dilution method. Isolates with intermediate CRO susceptibility were additionally tested for azithromycin susceptibility. Results demonstrated that the rate of resistance to PEN and CIP were 77.5 % and 94.2 %, respectively. Only 4 SPT-resistant and 2 SPT-intermediate isolates were identified. No CRO-resistant isolates were identified, although the percentage with intermediate susceptibility increased from 1.8% in 2012 to 11.9% in 2015. Among these, 3 isolates showed no susceptibility to azithromycin with 2 isolates showing an MIC of 0.5 μg/mL and 1 isolate showing an MIC of 1.0 μg/mL. We recommend azithromycin for treating strains that demonstrate intermediate susceptible to CRO and azithromycin-susceptible N. gonorrhoeae isolates occurring in Changsha.

Drug-resistance dynamics of Staphylococcus aureus between 2008 and 2014 at a tertiary teaching hospital, Jiangxi Province, China

Background

To understand the relationship between the Staphylococcus aureus infection rate and the reasonable usage of antibiotics, which will help in the effective control of MRSA infection.

Methods

All data were obtained by the application of the nosocomial infection surveillance network. Drug resistance, departmental sources, and isolated sites as well as infection rate variations of S. aureus were analyzed in the 7-year period in key departments.

Results

Between 2008 and 2014, 2525 strains of S. aureus isolates, mainly from sputum, skin/soft tissue, bloodstreams were collected from several hospital departments including respiratory, burn, brain surgery, orthopedics, ICU, and emergency. During these periods, the resistance rate of S. aureus to most drugs, including oxacillin, tetracycline, erythromycin, clindamycin, gentamicin, and ciprofloxacin, showed a tendency to decrease. The resistance to sulphamethoxazole/trimethoprim showed the opposite trend (P = 0.075) and there were no S. aureus strains resistant to linezolid and vancomycin. The MRSA infection rate was different across crucial hospital departments, with the burns department and ICU maintaining a high infection level. Over the 7-year period, both the brain surgery and the emergency departments had an expected upward trend (P < 0.05), while the orthopedic department showed a clear downward trend (P < 0.05) in MRSA infection rate.

Conclusion

Hospitals should continue to maintain the current pattern of antibiotic administration, while more effective measures should be taken to reduce the high MRSA infection rate in some important hospital departments.

Multidrug-Resistant Neisseria gonorrhoeae Isolates from Nanjing, China, Are Sensitive to Killing by a Novel DNA Gyrase Inhibitor, ETX0914 (AZD0914)

We tested the activity of ETX0914 against 187 Neisseria gonorrhoeae isolates from men with urethritis in Nanjing, China, in 2013. The MIC50, MIC90, and MIC range for ETX0914 were 0.03 μg/ml, 0.06 μg/ml, and ≤0.002 to 0.125 μg/ml, respectively. All isolates were resistant to ciprofloxacin, and 36.9% (69/187) were resistant to azithromycin. Of the isolates, 46.5% were penicillinase-producing N. gonorrhoeae (PPNG), 36% were tetracycline-resistant N. gonorrhoeae (TRNG), and 13% (24 isolates) had an MIC of 0.125 μg/ml for ceftriaxone. ETX0914 may be an effective treatment option for gonorrhea.