Advances in researches of polymyxin resistance mechanism in Klebsiella pneumoniae / 中华检验医学杂志

In recent years, the carbapenem-resistant Klebsiella pneumoniae (CRKP) continues to significantly threaten public health. The limited therapeutic options are increasingly challenging for clinicians to reintroduce the polymyxin as last-resort drug, with the results that polymyxin resistance is not scarce in settings. The polymyxin resistance mechanism is diversified, mainly the modification of the lipopolysaccharide (LPS). In addition to phoPQ, pmrAB, crrAB and mgrB on chromosome, plasmid-carried mcr gene have been found to mediate the LPS modification. The mgrB gene variation plays an important role in polymyxin resistance. Above all, the aim of the current review is to discuss the mechanism of polymyxin resistance mechanism in Klebsiella pneumoniae provide insights for preventing this phenomenon.

Clinical factors associated with composition of lung microbiota and important taxa predicting clinical prognosis in patients with severe community-acquired pneumonia / 医学前沿

Few studies have described the key features and prognostic roles of lung microbiota in patients with severe community-acquired pneumonia (SCAP). We prospectively enrolled consecutive SCAP patients admitted to ICU. Bronchoscopy was performed at bedside within 48 h of ICU admission, and 16S rRNA gene sequencing was applied to the collected bronchoalveolar lavage fluid. The primary outcome was clinical improvements defined as a decrease of 2 categories and above on a 7-category ordinal scale within 14 days following bronchoscopy. Sixty-seven patients were included. Multivariable permutational multivariate analysis of variance found that positive bacteria lab test results had the strongest independent association with lung microbiota (R2 = 0.033; P = 0.018), followed by acute kidney injury (AKI; R2 = 0.032; P = 0.011) and plasma MIP-1β level (R2 = 0.027; P = 0.044). Random forest identified that the families Prevotellaceae, Moraxellaceae, and Staphylococcaceae were the biomarkers related to the positive bacteria lab test results. Multivariable Cox regression showed that the increase in α-diversity and the abundance of the families Prevotellaceae and Actinomycetaceae were associated with clinical improvements. The positive bacteria lab test results, AKI, and plasma MIP-1β level were associated with patients' lung microbiota composition on ICU admission. The families Prevotellaceae and Actinomycetaceae on admission predicted clinical improvements.

Clinical features of Pneumocystis jirovecii pneumonia / 中华检验医学杂志

Objective:The clinical features, laboratory indices, and imaging data of patients with Pneumocystis jirovecii pneumonia (PJP) were described and analyzed, aiming to provide helpful information for the diagnosis and treatment of PJP. Methods:A retrospective study were conducted with data from 154 PJP patients who visited China-Japan Friendship Hospital from May 2017 to August 2020. Their clinical characteristics, laboratory and imaging data, and clinical outcomes were collected for analysis. The patients were further divided into the death group (51 cases) and the survival group(103 cases). The differences between the groups were compared by using t-test, nonparametric test, and chi-square test. Results:Of the 154 PJP patients, there were 89 males and 65 females, with a mean age of (53.7±14.8) years. Among them, 85.7% (132/154) were on immunosuppressive/glucocorticoids agents within the past month. Besides, 27.9% (43/154) and 33.1% (51/154) had kidney diseases and connective tissue diseases, respectively. The major clinical manifestations in these patients involved fever 82.9% (126/154), cough 59.7% (92/154), and dyspnea 52.6% (81/154). For the laboratory data, the lactate dehydrogenase (LDH) was 561.0 (434.3, 749.0) IU/L and the value increased in 91.3% (95/104) of the patients. The CD4+T-cell lymphocytes in 88.0% (95/108) and 57.4% (62/108) of patients were lower than 400/μl and 200/μl, respectively. Furthermore, (1, 3)-β-D glucan (BG) increased in 74.4% (67/90) of PJP patients (≥100.0 ng/L). For the imaging results, chest computed tomography (CT) showed diffuse ground-glass shadows/grid shadows in 90% (117/130) patients. Compared with the survival group, higher LDH [690.5 (528.8, 932.3) IU/L vs 502.5 (381.8, 657.0) IU/L, Z=-3.375, P=0.001], white blood cell count (WBC) [9.8 (5.8, 12.6) ×10 9/L vs 7.3 (5.0, 10.1) ×10 9/L, Z=-2.392, P=0.017], and age [(69.8±14.5) years vs (50.6±14.0) years, t=-3.756, P=0.001] were found in the death group. Lower lymphocyte ratio [5.3 (3.2, 9.3) % vs 9.6 (5.6, 17.2) %, Z=?3.262, P=0.001] and oxygen partial pressure (PaO 2) levels [(73.2±20.5) mmHg vs (64.8±17.7) mmHg (1 mmHg=0.133 kPa), t=2.345, P=0.021] were also observed in the death group. Furthermore, in the death group, the bacterial and fungal infection rate was higher than the rates in the survival group [55.1% (27/51) vs 21.5% (22/103), χ 2=15.372, P=0.001]. Conclusions:Long-term use of immunosuppressive agents or glucocorticoids predispose to PJP. CD4+T-lymphocytes, LDH, and BG might be used as important auxiliary examinations for PJP patients. Age, LDH, WBC, lymphocyte ratio, PaO 2 and possible combinations with bacterial or fungal infections are more closely related to the prognostic of PJP patients.

Discussion on the role of case design in PBL teaching in laboratory diagnostics / 中华医学教育探索杂志

Objective:To investigate the role and influencing factors of case design in PBL teaching.Methods:Thirty-two six-year-program undergraduates from the Department of Medicine of Peking University in batch 2014 and batch 2015 were selected as the subjects. PBL teaching was used in the practice class of experimental diagnostics. The feedback effects of four times PBL courses were analyzed by collecting questionnaires for teachers, students, and supervisors. The data obtained from the five-point questionnaire and the question-and-answer questionnaire were analyzed by one-way ANOVA and statistics respectively. Then the problems in case preparation process are discussed and the experience of case design is summarized. SPSS 13.0 was used in this study.Results:The 5-point questionnaire showed that the average score of anemia PBL course was the highest among students' self-evaluation and mutual evaluation of teachers and students (4.84 points, 4.79 points), with statistical significance compared with other courses ( P<0.05). The question-and-answer questionnaire survey showed that 93.75% of the students generally agreed with the teaching model of anemia cases; 78.13% and 59.38% of the students believed that it was difficult to set up cases of infection and coagulation, which affected the classroom effect; and 50% of the supervisors thinked that the students' level should be taken into account in case design and oral expression should be avoided. Conclusion:Case design is the key to PBL teaching. Summarizing the experience of case design can lay a good foundation for the establishment of PBL teaching database.

Clinical analysis of 26 cases of maternal or neonatal listeriosis / 中华围产医学杂志

Objective@#To improve clinical management of maternal and neonatal listeriosis through analyzing the clinical characteristics and antibiotic treatment.@*Methods@#A retrospective analysis of 26 cases of listeriosis, including their demographic and clinical features, was conducted, involving 16 pregnant women from Civil Aviation General Hospital, Xiamen Humanity Hospital, Tongzhou Maternal and Child Health Hospital of Beijing, Beijing Tiantan Hospital, Tangshan Maternal and Child Health Hospital, the Fourth Hospital of Tianshui City from October, 2011 to May, 2018, and 10 newborns from the Fourth Hospital of Tianshui City, Tangshan Maternal and Child Health Hospital, Zhengzhou Children's Hospital from February, 2016 to April 2018. Descriptive methods were used for data analysis.@*Results@#(1) Among the 16 gravidas, one, five and 10 developed the infection in the 1st, 2nd and 3rd trimester of pregnancy, respectively, and eight had pregnancy complications. Furthermore, all of them developed fever [(38.9±0.5) ℃]. Symptoms such as cough, nasal congestion, runny nose, sore throat, dizziness, headache and other flu-like symptoms were observed in six cases. Gastrointestinal symptoms and flu-like symptoms were presented in four. Fetal distress, tachycardia and decreased fetal movement occurred in 11 cases. Elevated C-reactive protein and white blood cell count were detected in 16 and 14, respectively. Eight underwent placental pathological examination which shown various degrees of pathological changes, including neutrophil infiltration, acute chorioamnionitis and inflammatory necrosis. The main empirical antibiotic treatment for the 16 patients was cephalosporins and only four covered Listeria monocytogenes. Only two delivered at term, while the others (14/16) ended in miscarriage, premature delivery or stillbirth. (2) Among the 10 newborns with listeriosis, there were eight early-onset infections and two late-onset infections. All of them were febrile [(38.6±0.6)℃]. Six had cyanosis, groaning, foaming and three concave sign; five showed shortness of breath; meningitis and skin rash were found in one, respectively. All had elevated white blood cell and C-reactive protein. Six received antibiotics covering Listeria monocytogenes during the initial empirical treatment. Four were treated with cephalosporins alone, one of which died after the treatment was withdrawn. One was cured by initial treatment with meropenem alone, while eight recovered after adjustment of treatment with ampicillin, penicillin, meropenem, vancomycin alone, or meropenem combined with ampicillin or vancomycin. (3) The isolates that were susceptible to penicillin, ampicillin and meropenem accounted for 96.1% (25/26) all together and 88.5% (23/26) were susceptible to compound sulfamethoxazole.@*Conclusions@#There is no specific clinical manifestations of maternal or neonatal listeriosis. Maternal listeriosis is often characterized by acute onset and high incidence of adverse pregnancy outcomes.

Clinical analysis of 26 cases of maternal or neonatal listeriosis / 中华围产医学杂志

Objective To improve clinical management of maternal and neonatal listeriosis through analyzing the clinical characteristics and antibiotic treatment.Methods A retrospective analysis of 26 cases of listeriosis,including their demographic and clinical features,was conducted,involving 16 pregnant women from Civil Aviation General Hospital,Xiamen Humanity Hospital,Tongzhou Maternal and Child Health Hospital of Beijing,Beijing Tiantan Hospital,Tangshan Maternal and Child Health Hospital,the Fourth Hospital of Tianshui City from October,2011 to May,2018,and 10 newborns from the Fourth Hospital of Tianshui City,Tangshan Maternal and Child Health Hospital,Zhengzhou Children's Hospital from February,2016 to April 2018.Descriptive methods were used for data analysis.Results (1) Among the 16 gravidas,one,five and 10 developed the infection in the 1st,2nd and 3rd trimester of pregnancy,respectively,and eight had pregnancy complications.Furthermore,all of them developed fever [(38.9± 0.5) ℃].Symptoms such as cough,nasal congestion,runny nose,sore throat,dizziness,headache and other flu-like symptoms were observed in six cases.Gastrointestinal symptoms and flu-like symptoms were presented in four.Fetal distress,tachycardia and decreased fetal movement occurred in 11 cases.Elevated C-reactive protein and white blood cell count were detected in 16 and 14,respectively.Eight underwent placental pathological examination which shown various degrees of pathological changes,including neutrophil infiltration,acute chorioamnionitis and inflammatory necrosis.The main empirical antibiotic treatment for the 16 patients was cephalosporins and only four covered Listeria monocytogenes.Only two delivered at term,while the others (14/16) ended in miscarriage,premature delivery or stillbirth.(2) Among the 10 newborns with listeriosis,there were eight early-onset infections and two late-onset infections.All of them were febrile [(38.6±0.6)℃].Six had cyanosis,groaning,foaming and three concave sign;five showed shortness of breath;meningitis and skin rash were found in one,respectively.All had elevated white blood cell and C-reactive protein.Six received antibiotics covering Listeria monocytogenes during the initial empirical treatment.Four were treated with cephalosporins alone,one of which died after the treatment was withdrawn.One was cured by initial treatment with meropenem alone,while eight recovered after adjustment of treatment with ampicillin,penicillin,meropenem,vancomycin alone,or meropenem combined with ampicillin or vancomycin.(3) The isolates that were susceptible to penicillin,ampicillin and meropenem accounted for 96.1％ (25/26) all together and 88.5％ (23/26) were susceptible to compound sulfamethoxazole.Conclusions There is no specific clinical manifestations of maternal or neonatal listeriosis.Maternal listeriosis is often characterized by acute onset and high incidence of adverse pregnancy outcomes.

Use of MALDI-TOF mass spectrometry for rapid identification of group B Streptococcus on chromID Strepto B agar.

BACKGROUND: Group B Streptococcus (GBS) is a known leading causative pathogen of neonatal infection. Efficient screening and identification of women colonized with GBS is important for the prevention of invasive neonatal infections. METHODS: A total of 628 vaginal/rectal specimens were collected from pregnant women in Beijing, China. The chromogenic medium chromID Strepto B agar (STRB) was evaluated for its reliability in screening GBS from the vaginal/rectal swabs; results were compared to those of blood agar plates (BAP). Furthermore, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was used to confirm the colonies suspected of being GBS on STRB. RESULTS: STRB showed excellent performance for GBS detection and outperformed BAP due to its higher sensitivity. Furthermore, MALDI-TOF MS could reliably differentiate the putative GBS isolates on STRB. CONCLUSIONS: This study demonstrated that STRB combined with MALDI-TOF MS is a fast, sensitive, and accurate method for the identification of GBS-colonized pregnant women.

Intrauterine infection and post-partum bacteraemia due to Streptococcus gallolyticus subsp. pasteurianus.

The case is presented of a woman with intrauterine infection and post-partum bacteraemia due to Streptococcus gallolyticus subsp. pasteurianus, who delivered an infant via Caesarean section. Furthermore, we comment on the possibility of vaginal colonization of this organism as a portal of entry in cases of maternal and neonatal infections.

Protective Effect of"Compound Antioxidant Herb"on Rat Gastric Injury Caused by Stress / 中草药

Protective effect of Chinese medicinal Lerbs against gastric stress injury was studied.The compound antioxidant prescription used was composed of ten herbs, each of which had proven antiperoxidation action. Bound-soaked rats were used as victims of stress injury. In the two groups of rats under protection of the "prescription and injection of salvia" the indexes of gastric mucosa injury were 8.50?2.31 and 19.00?4.25, LPO in serum were 10.74? 0.94 and 11.80? 1. 06nmol/ml respectively. Both were significantly decreased as compared with the control group (39.00? 6.50, LPO 19.06? 1. 10nmol/ml ). These results signified that the antioxidant medicinal herbs, especially in compounded form, may prevent gastric stress injury