Genotyping Characteristics of Human Fecal Escherichia coli and Their Association with Multidrug Resistance in Miyun District, Beijing

Objective To explore the genotyping characteristics of human fecal Escherichia coli(E. coli) and the relationships between antibiotic resistance genes(ARGs) and multidrug resistance(MDR) of E. coli in Miyun District, Beijing, an area with high incidence of infectious diarrheal cases but no related data.Methods Over a period of 3 years, 94 E. coli strains were isolated from fecal samples collected from Miyun District Hospital, a surveillance hospital of the National Pathogen Identification Network. The antibiotic susceptibility of the isolates was determined by the broth microdilution method. ARGs,multilocus sequence typing(MLST), and polymorphism trees were analyzed using whole-genome sequencing data(WGS).Results This study revealed that 68.09% of the isolates had MDR, prevalent and distributed in different clades, with a relatively high rate and low pathogenicity. There was no difference in MDR between the diarrheal(49/70) and healthy groups(15/24).Conclusion We developed a random forest(RF) prediction model of TEM.1 + baeR + mphA + mphB +QnrS1 + AAC.3-IId to identify MDR status, highlighting its potential for early resistance identification. The causes of MDR are likely mobile units transmitting the ARGs. In the future, we will continue to strengthen the monitoring of ARGs and MDR, and increase the number of strains to further verify the accuracy of the MDR markers.

The Impact of Haze Weather on Health: A view to Future

In January 2013, China suffered large-scale haze weather four times, affecting 30 cities in all. The average number of haze weather days in many regions was higher than the same period in every year since 1961. PM2.s, which is defined as fine particulate matter with an aerodynamic diameter of 2.5 micrometers or less, is the main health hazard in the context of haze weather. It can carry large amounts of poisonous and harmful substances, and penetrate deep into the lungs and blood circulation through the respiratory tract, thereby affecting human health.

Comparing the Genotype and Drug Susceptibilities between Mycobacterium avium and Mycobacterium intracellulare in China

Objective Mycobacterium avium （M. avium） and Mycobacterium intracellulare （M. intracellulare） are the major causative agents of nontuberculous mycobacteria （NTM）-related pulmonary infections. However, little is known about the differences in drug susceptibility profiles between these two species. Methods A total of 393 NTM isolates were collected from Shanghai Pulmonary Disease Hospital. Sequencing of partial genes was performed to identify the strains at species level. The minimum inhibitory concentration （MIC） was used to evaluate the drug susceptibility against 20 antimicrobial agents. Variable number of tandem repeat （VNTR） typing was conducted to genotype these two species. Results A total of 173 （44.0%） M. avium complex （MAC） isolates were identified, including 41 （10.4%） M. avium isolates and 132 （33.6%） M. intracellulare isolates. Clarithromycin and amikacin were the two most effective agents against MAC isolates. The Hunter-Gaston Discriminatory Index （HGDI） values for VNTR typing of M. avium and M. intracellulare isolates were 0.993 and 0.995, respectively. Levofloxacin resistance was more common among the unclustered strains than among the clustered strains of M. intracellulare. Conclusion M. intrecellulare was the most common NTM species in China. Clarithromycin and amikacin had high antimicrobial activities against MAC. VNTR typing of MAC isolates revealed a high discriminatory power. Levofloxacin resistance was associated with unclustered strains of M. intracellulare.

Follow-up Study of Retreatment TB Patients with Sputum Smear and/or Culture Positive Two Years after They were Declared Cured with First-line Anti-TB Drugs in Shandong Province

This study aimed to learn the recurrence rate in the retreatment TB patients with sputum smear and/or culture positive （ss＋ and/or c＋） two years after they were declared cured, and to explore causes of recurrence in order to improve long-time treatment outcome. 5 cities were selected as research locations. Recurrence of TB was judged by chest X-ray examination together with sputum smear and culture examination.

The Current Status and Challenges Regarding Tuberculosis Infection Control in Health Care Facilities in China

Health care facilities are a high-risk environment for generating and spreading respiratory infectious diseases such as tuberculosis （TB）. The TB prevention and treatment staff in health care facilities are responsible for the identification, diagnosis, treatment, supervision, and management of TB patients .

Genetic Diversity and Drug Susceptibility of Mycobacterium tuberculosis Isolates in a Remote Mountain Area of China

Objective We determined the genetic diversity of Mycobacterium tuberculosis（MTB） in a remote mountainous area of southwest China and evaluated the resolving ability of single nucleotide polymorphism（SNP） genotyping combined with variable number tandem repeat（VNTR） genotyping for Beijing family strains in association with drug resistance status.Methods Three hundred thirty-one MTB strains were isolated from patients living in mountainous regions of southwest China,and 8-loci SNP,VNTR-15 genotyping assays,and drug susceptibility testing of 9 drugs were performed.Results A total of 183 [55.29%（183/331）] strains were classified into the Beijing family.Of the 183 strains,111（60.66%） were defined as modern Beijing strains.The most predominant modern Beijing sub-lineage and ancient Beijing sub-lineage were Bmyc10 [39.34%（72/183）] and Bmyc25 [20.77%（38/183）],respectively.Of the isolates,19.64%（65/331） were resistant to at least 1 of the 9 anti-TB drugs and 17 [4.98%（17/331）] MTB isolates were multi-drug resistant tuberculosis（MDR-TB）.Two hundred sixty-one isolates showed a clustering rate of 14.18%（37/261） and a discriminatory index of 0.9990.The Beijing lineage exhibited a significantly higher prevalence of MDR-TB,as well as resistance to isoniazid（INH）,rifampin（RIF）,and para-aminosalicylic acid（PAS） when analyzed independently（P = 0.005,P = 0.017,P = 0.014,and P = 0.006 respectively）.The Beijing lineage was not associated with genetic clustering or resistance to any drug.In addition,genetic clustering was not associated with drug resistance.Conclusion MTB strains demonstrate high genetic diversity in remote mountainous areas of southwest China.Beijing strains,especially modern Beijing strains,are predominant in remote mountainous area of China.The combination of 8-loci SNPs and VNTR-15 genotyping is a useful tool to study the molecular epidemiology of MTB strains in this area.

Epidemiological Characteristics of Notifiable Infectious Diseases among Foreign Cases in China,2004–2017

Objective We aimed to assess the features of notifiable infectious diseases found commonly in foreign nationals in China between 2004 and 2017 to improve public health policy and responses for infectious diseases.Methods We performed a descriptive study of notifiable infectious diseases among foreigners reported from 2004 to 2017 in China using data from the Chinese National Notifiable Infectious Disease Reporting System(NNIDRIS). Demographic, temporal-spatial distribution were described and analyzed.Results A total of 67,939 cases of 33 different infectious diseases were reported among foreigners.These diseases were seen in 31 provinces of China and originated from 146 countries of the world. The infectious diseases with the highest incidence number were human immunodeficiency virus(HIV) of18,713 cases, hepatitis B(6,461 cases), hand, foot, and mouth disease(6,327 cases). Yunnan province had the highest number of notifiable infectious diseases in foreigners. There were different trends of the major infectious diseases among foreign cases seen in China and varied among provinces.Conclusions This is the first description of the epidemiological characteristic of notifiable infectious diseases among foreigners in China from 2004 to 2017. These data can be used to better inform policymakers about national health priorities for future research and control strategies.

Prevalence of Tuberculosis among Close Contacts of Index Cases in 27 Universities in Beijing,China,2017-2018

The World Health Organization(WHO)launched the‘End TB Strategy’,which aims to reduce the mortality and incidence rate of tuberculosis(TB)by 95% and 90% by 2035,respectively,compared with the levels in 2015.To achieve these targets and milestones,the strategy set three pillars and 10 indicators,one of which is systematic screening of contacts and high-risk groups[1].

Antimicrobial Susceptibility Testing and Molecular Characterization of Mycobacterium fortuitum Isolates in China

We performed molecular identification of clinical isolates of Mycobacterium fortuitum（M. fortuitum） and conducted drug susceptibility testing to analyze the in vitro susceptibility of clinical M. fortuitum isolates and potential molecular mechanism conferring resistance to fluoroquinolone and macrolide drugs. The results showed that moxifloxacin had the highest in vitro activity against M. fortuitum, and most M. fortuitum isolates were resistant to clarithromycin and linezolid in China. The loss of genetic mutation in clarithromycin-and amikacin-resistant isolates indicates that some other intrinsic mechanism conferring clarithromycin and amikacin resistance plays an essential role in M. fortuitum infection.