Expert Consensus on Polymyxin Antimicrobial Susceptibility Testing and Clinical Interpretation / 中国医学科学杂志(英文版)

The polymyxins are important antimicrobial agents against antibiotic-resistant gram-negative bacilli. In 2020, the Clinical and Laboratory Standards Institute modified the clinical breakpoints for polymyxin susceptibility test by eliminating the "susceptible" interpretive category, only reporting intermediate (≤2 mg/L) and resistant (≥4 mg/L). However, the European Committee on Antimicrobial Susceptibility Testing recommended the use of clinical breakpoints of ≤2 mg/L as susceptible and >2 mg/L as resistant. The first-line laboratorians and clinicians in China have been perplexed by the inconsistence of international polymyxin clinical breakpoints and discouraged by the difficulty of conducting polymyxin susceptibility testing. Therefore, it is urgently needed to make it clear for the laboratorians in China to know how to accurately carry out polymyxin susceptibility testing and standardize the interpretation of susceptibility testing results. To this end, the experts from relevant fields were convened to formulate this consensus statement on the testing and clinical interpretation of polymyxin susceptibility. Relevant recommendations are proposed accordingly for laboratorians and clinicians to streamline their daily work.

Clinical and Laboratory Characteristics of Disseminated Non-tuberculous Mycobacterial Disease / 中国医学科学院学报

Objective To explore the clinical and laboratory characteristics and the prognosis of disseminated non-tuberculous mycobacteria(NTM)diseases in human immunodeficiency virus(HIV)negative patients. Methods Cases of disseminated NTM disease were retrospectively collected in Peking Union Medical College Hospital from January 2012 to October 2018.Clinical manifestations,laboratory findings,treatment,and prognosis of these cases were retrieved from the electronic medical record system. Results Among the 23 HIV negative patients with disseminated NTM disease,21 had underlying diseases,with rheumatoid immune disease(n=7)as the most common one.The main clinical manifestation was fever(n=23).Laboratory tests showed anemia [hemoglobin(85.78±25.47)g/L],hypoalbuminemia [albumin 29(27-32)g/L],elevated erythrocyte sedimentation rate [(85.73±43.78)mm/h] and hypersensitive C-reactive protein [(112.00±70.90)mg/L],and reduction of lymphocyte count [0.69(0.29-2.10)×10 /L].Lymphocyte subset analysis indicated reduction in CD4 T cells [213(113-775)/μl],CD8 T cells [267(99-457)/μl],B cells [39(4-165)/μl],and NK cells [88(32-279)/μl] and elevation of human leukocyte antigen-D related(HLA-DR),and CD38 expression in CD8 T cells [HLA-DR CD8 /CD8 ,60(40-68)%;CD38 CD8 /CD8 ,81(65-90)%].The most common species of NTM was Mycobacterium intracellular(n=6).Lymphocyte,CD8 T cell,B cell,and NK cell counts were significantly lower in dead patients than surviving patients(P =0.045,P=0.045,P=0.032,and P=0.010,respectively). Conclusions Disseminated NTM disease in HIV negative patients is mainly manifested as fever,anemia,hypoalbuminemia,and elevated inflammatory indicators.It is more likely to occur in immunocompromised patients.Patients with decreased lymphocytes,CD8 T cells,B cells and NK cells tend to have a poor prognosis.

Influence of Nasal Disinfection on Nasal Bacterial Colonization through the Transsphenoidal Approach / 中国医学科学院学报

Objective To explore the influence of the iodine disinfection on nasal bacterial colonization through the transsphenoidal approach. Methods Totally 133 pituitary adenoma patients who underwent transsphenoidal surgery in our department from January to August 2017 were enrolled in this study. Before disinfection,pharyngeal swabs of inferior turbinate root secretions were taken for bacterial culture. After iodine disinfection,pharyngeal swabs were taken again at the same site. Changes in the nasal bacterial spectrum before and after disinfection were compared. Patients were followed up for three months after the surgery,during which any intracranial infection/bacteraemia was recorded,and its correlation with nasal bacteria colonization was analyzed. Results Nasal bacterial colonization was detected in 45 (33.8%) of 133 patients before iodine disinfection and in only 6 cases (4.5%) after iodine disinfection (χ=34.5,P=0.000). Thus,iodine disinfection eliminated 86.7%(39/45) of the colonized bacteria. The most common nasal bacterium was Staphylococcus aureus (24.4%,11/45),followed by Klebsiella pneumoniae (24.4%,11/45),and Staphylococcus epidermidis (13.3%,6/45). One patient had high fever and chills 2 days after surgery,but blood culture and cerebrospinal fluid culture showed negative Results . After the administration of third-generation cephalosporins,the symptoms disappeared after two days. Conclusion sThere are colonized bacteria in nasal cavity. Iodine disinfection of nasal cavity can effectively clear most of the nasal bacteria. The possibility of intracranial infection/bacteremia after transsphenoidal approach is low.

Clinical and Laboratory Characteristics of Patients with Nontuberculous Mycobacterium Bloodstream Infection in a Tertiary Referral Hospital in Beijing, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nontuberculous Mycobacterium (NTM) bloodstream infection (BSI) is relatively rare. We aimed in this study to evaluate the clinical characteristics, laboratory evaluation, and outcomes of patients with NTM BSI.</p><p><b>METHODS</b>We retrospectively reviewed the clinical records of inpatients with NTM BSI at our institution between January 2008 and January 2015 and recorded clinical parameters including age, gender, underlying disease, clinical manifestation, organs involved with NTM disease, species of NTM, laboratory data, treatment and outcome of these patients. We also reviewed the reported cases and case series of NTM BSI by searching PubMed, EMBASE, and Wanfang databases. Data of normal distribution were expressed by mean ± standard deviation (SD). Data of nonnormal distribution were expressed by median and interquartile range (IQR).</p><p><b>RESULTS</b>Among the ten patients with NTM BSI, the median age was 51 years (IQR 29-57 years) and three patients were males. Eight patients were immunocompromised, with underlying diseases including human immunodeficiency virus (HIV) infection (one patient), rheumatic diseases (two patients), breast cancer (one patient), myelodysplastic syndrome (two patients), and aplastic anemia (two patients). Other organ(s) involved were lung (two patients), endocardium (two patients), brain, spinal cord, and soft tissue (one each patient). The median lymphocyte was 0.66 × 109/L (IQR 0.24-1.93 × 109/L). The median cluster of differentiation 4 (CD4) cell count was 179/mm3 (IQR 82-619/mm3). Five patients died (three with hematological diseases, one with breast cancer, and one with rheumatic disease), three recovered, and two were lost to follow-up.</p><p><b>CONCLUSIONS</b>We reported all cases in our hospital diagnosed with bloodstream NTM infection that was rarely reported. In this group of patients, patients usually had a high fever and could have multiple organ involvements. All patients with poor prognosis had underlying diseases.</p>

In vitro antimicrobial activity of ampicillin-sulbactam,clindamycin and cefoperazone determined by E test / 中国感染与化疗杂志

Objective To investigate the in vitro antimicrobial activity of ampicillin-sulbactam,clindamycin and cefoperazone a- gainst common clinical isolates.Methods MICs of these three antibiotics were determined by E test.Results Ampicillin-sulbae- tam showed inhibition rate of 100% for methicillin susceptible S.aureus (MSSA),E.faecalis,Group A Streptococcus,H. influenzae,penicillin-susceptible S.pneumoniae (PSSP),M.catarrhalis and anaerobes (including 10 strains of Bacteroid spp.,2 strains of P.aches,1 strain of E.lentum,1 strain of Fusobacterium innocuum,and 2 strains of Peptostreptococcus spp.).Ampicillin-sulbactam was active against 86.7% of extended-spectrum?-lactamase non-producing K.pneumoniae (NES- BL-KPN) and 53.3% of non ESBL-producing E.coli (NESBL-ECO).Ampicillin-sulbactam only inhibited 23.3% of A.bau- mannii isolates and 25.0% of E.faecium isolates.For MSSA,anaerobes,PSSP and group A Streptococcus,about 60.0%, 31.2%,30.0% and 10.0% of the isolates were susceptible to clindamycin,respectively.For MSSA,NESBL-ECO and NES- BL-KPN,96.7% to 100% of the isolates were susceptible to cefoperazone.About 40.0% of P.aeruginosa isolates were sus- ceptible to cefoperazone.No A.baumannii isolate was susceptible to cefoperazone.Conclusions The ampicillin-sulbactam has good antimicrobial activity against MSSA,E.faecalis,Group A Streptococcus,NESBL-KPN,H.influenzae,PSSP,M.ca- tarrhalis and anaerobes.In this study,clindamycin is active against 60% of MSSA isolates.Most of other species are relatively resistant to clindamycin.Cefoperazone shows good activity against MSSA,NESBL-ECO,and NESBL-KPN.These three anti- microbial agents can be used as empirical treatment for community-acquired infections.