[A retrospective cohort study on the correlation between early energy management and bronchopulmonary dysplasia in premature infants].

Objective: To investigate the correlation between early energy supplement and bronchopulmonary dysplasia (BPD) in very preterm and very low birth weight infants. Methods: A retrospective cohort study design was used. A total of 939 preterm infants who were admitted to the Department of Neonatology of the West China Second Hospital of Sichuan University within 24 h after birth from January 2019 to December 2021 were enrolled in the study. They were born with a gestational age of <32 weeks and (or) a birth weight of <1 500 g. Of them, 250 preterm infants who developed BPD were enrolled in the BPD group, and each of them was matched to a preterm infant who did not develop BPD (matched for gestational age and birth weight) in the order of priority after calculating propensity score. Their total energy, enteral energy, parenteral energy, total fluid intake and energy per unit of fluid per week were collected within the first 2 weeks of life. The independent sample t-test or Mann Whitney U test was used for continuous variables, and the χ2 test for between-group comparisons of categorical variables. Univariate and multivariate Logistic regression analyses were used to explore the association between total energy and total fluid and BPD incidence, respectively. The dose-response relationship between parenteral energy and BPD was investigated by a generalized additive model, and the threshold effect of parenteral energy on BPD used a two-piecewise linear regression model. Results: The gestational age was (28.4±1.9) weeks in the BPD group and (29.5±1.3) weeks in the control group; the birth weight was (1 107±258) g in the BPD group and (1 324±261) g in the control group; and there were 140 males (56.0%) and 131 males (52.4%) in each group, respectively. An increase in energy per unit of fluid in the second week of life was associated with a reduced risk of BPD (OR=0.32, 95%CI 0.12-0.84, P=0.021), and an increase in total energy in the second week of life was also associated with a reduced risk of BPD, with total energy of >418-502 kJ/(kg·d) was significantly lower than when total energy was ≤334 kJ/(kg·d) (OR=0.15, 95%CI 0.03-0.85, P=0.033). There was no association between the average total fluid intake and BPD incidence (both P>0.05) in the first and second week. The increase in the proportion of parenteral energy to total energy in the second week of life was associated with an increased incidence of BPD (OR=8.45, 95%CI 2.14-33.32, P=0.003); specifically, the risk of BPD significantly increased when the parenteral energy was ≥305 kJ/(kg·d) (OR=1.02, 95%CI 1.01-1.03, P=0.003). Conclusions: Maintaining a high total energy supply in the early postnatal period in preterm infants may reduce the risk of BPD, but continued reliance on high parenteral energy to meet total energy requirements increases the risk of BPD, so enteral feeds should be initiated as early as possible and maximized as tolerated.

[Characteristics of molecular typing and drug resistance of 67 Salmonella paratyphi A isolated in Zhengzhou from 2013 to 2015].

Objective: To investigate the antimicrobial resistance and pulsed field gel electrophoresis (PFGE) patterns of S.paratyphi A strains in Zhengzhou city isolated from sentinel hospitals in 2013-2015. Methods: According to Salmonella molecular typing and K-B drug susceptibility testing method published by international PulseNet bacterial infectious disease monitoring network and USA Clinical and Laboratory Standards Institute (CLSI2015), we analyzed drug sensitivity and PFGE molecular characteristics of 67 S.paratyphi A strains(11 strains in 2013, 7 strains in 2014, 49 strains in 2015) isolated from blood and stool samples in two sentinel hospitals of fever with rash syndrome surveillance system established in Zhengzhou city in 2013-2015. Results: The results showed 67 strains of S.paratyphi A had different levels of resistance to 13 kinds of antibiotics, 65 strains were multi-drug resistant strains (97.0%), 5 isolates were resistant to 2-3 kinds of antibiotics (7.5%), 41 isolates were resistant to 5-8 kinds of antibiotics (61.2%),11 isolates were resistant to 9-10 kinds of antibiotics(16.4%),8 isolates were resistant to 11-12 kinds of antibiotics(11.9%). 67 strains of S.paratyphi A were divided into 10 molecular patterns(PTYA1-PTYA10) by digestion with XbaⅠ restriction endonuclease and pulsed field gel electrophoresis, each pattern contains 1-48 strains with similarity ranged from 94.31%-100%. PTYA3 contained 48 strains, which was predominant band type; PTYA1, 9 contained 6 strains; PTYA 2, 4, 5, 6, 7, 8, 10 contained 1 strains among them. Conclusion: The status of drug resistance of clinical isolates of S.paratyphi A in Zhengzhou city was rather serious, PFGE patterns showed diversity and dominant characteristics. The PFGE patterns of partial strains and its corresponding anti-drug spectrum have certain relevance and cluster relationship.

[Infection status, clinical symptoms and gene type transition of group A rotavirus in children, less than five years-of-age, with diarrhea in sentinel hospitals of Henan Province, China].

Objective: To investigate the infectious status, gene type transition and epidemiological features of rotavirus A isolated from infants and children (<59 months-of-age) in sentinel hospitals from 2008 to 2015 in Henan province, China. Methods: In total, 2 541 stool samples (each 3- 5 ml) were collected from infants and children aged less than five years in two sentinel hospitals and group A rotavirus was detected by a double antibody sandwich ELISA. Viral RNA was extracted from positive samples and G/P gene typing was performed using a two-step nested multiplex RT-PCR. Epidemiological information (including demographic information such as age, sex and clinical symptoms) was also collected from the patients and analyzed. Results: Group A rotavirus was detected in 30.9% (785/2 541) of diarrhea samples from children. The detection rate was higher in October (54.8%, 345/629) and lower in July (5%, 5/101) each year from 2008 to 2015. The group A rotavirus infection rate was higher in boys (30.6%, 451/1 476) than in girls (31.4%, 334/1 065) (χ2=0.18, P=0.664). Infection mainly occurred in 4-12 months old patients (61.3%, 481/785) (χ2=196.69, P<0.001), and the infection rate was lower in cities (26%, 258/992) compared with rural areas (34.0%, 527/1 549) (χ2=18.19, P<0.001). G typing of 785 strains of group A rotavirus revealed the following types: G1 (13.5%, 106 strains), G2 (11.1%, 87 strains), G3 (29.7%, 233 strains), and G9 (57.5%, 451 strains); P typing revealed the predominance of P[4] (11.3%, 89 strains) and P[8] (84.7%, 665 strains); gene type combinations comprised mainly G9P[8], G2P[4], G3P[8], G1P[8], respectively accounted for 52.9% (415), 9.7% (76), 17.3% (136), 11.3% (89). Gene type combinations G1 [8] and G3P[8] have been decreasing in prevalence since 2008 and G9P[8] has become the dominant gene type of group A rotavirus in Henan province. Among the group A rotavirus infection samples, the male:female infection ratio was 1.4∶1 (451/334), with no significant difference in the infection rate (χ2=0.18, P=0.664); the infection rate was higher in 4- 12 months old patients (61.3%, 481/785), with a significant difference detected between age groups (χ2=196.69, P<0.001). The rate of detection was lower in cities (26.0%, 258/992) than in rural areas (34.0%, 527/1 549) (χ2=18.19, P<0.001). Clinical analysis revealed a body temperature of below 37 degrees in 75.7% of positive cases (594 patients), 37.0- 37.5 degrees in 17.2% of cases (135 patients), 37.6-38.0 degrees in 2.0% of cases (16 patients), and above 38 degrees in 5.1% of cases (40 patients), with most cases showing no fever or a mild fever. The frequency of episodes of diarrhea among the patients was 0- 3 times (21.1%, 166 cases), 4- 6 times (65.6%, 515 cases), 7- 9 times (8.0%, 63 cases), or 10- 15 times (5.2%, 41 cases), mainly showing mild and moderate diarrhea. Vomiting also varied in frequency among the patients from no vomiting (86.9%, 682 cases), 1-2 times (11.8%, 92 cases), 3 times (6.0%, 47 cases), and more than 3 times (0.4%, 3 cases). The occurrence of dehydration varied from no dehydration (86.9%, 682 cases), mild dehydration of 1%- 5% (12.1%, 95 cases), to severe dehydration of ≥5% (1.0%, 8 cases). Conclusion: A higher infection rate of group A rotavirus was detected in children younger than five years of age with acute diarrhea in sentinel hospitals in Henan province, including part-mixed infection cases. A predominance of cases was detected in the autumn, and secondly the spring of each year. Gene type G9P[8] was most frequently isolated. The majority of patients displayed no fever, vomiting or dehydration. The cases with clinical symptoms of fever, diarrhea, vomiting and dehydration often showed mild disease.

[Distribution and molecular type of Salmonella from external environment in Henan province].

Objective: To understand the distribution of Salmonella in external environment in Henan province, and explore the distribution of different serotypes of the Salmonella and their homology. Methods: A total of 4 488 samples were collected form animal dung, meat products and kitchen utensils, and identified by biochemical tests and serotyped by serum agglutination reaction. The predominant serotypes were further typed by PFGE. Results: A total of 324 Salmonella strains were detected in these samples, the detection rate was 7.21%. The 324 Salmonella isolates belonged to 39 serotypes, S. enteritidis (24.07%, 78/324) and S. derby (20.37%, 66/324) were predominant. Forty six strains of S. enteritidis and 30 strains of S. derby were divided into 12 and 17 molecular patterns by digestion with Xba Ⅰ, while chicken and swine were the predominant animal hosts. Conclusions: Serotyping of external environment Salmonella were phenotypically diverse and the serotype of Salmonella from different sources were different. The same clone was prevalent in same area. It is necessary to strengthen supervision and surveillance to ensure food safety.

[Etiology and drug resistance of non-typhi Salmonella in Henan province, 2011-2015].

Objective: To analyze the serotypes and antibiotic resistance phenotypes of non-typhi Salmonella strains in Henan province from 2011 to 2015. Methods: The stool samples were collected from diarrhea patients, and enriched with SBG enrichment broth and the pathogen isolation was conducted with CHROMAgar selective culture medium at 37 ℃ for 18-24 hours using KIA/MIU biochemical action and API20E biochemical system slab to identify Salmonella strains. The serotypes of all the positive strains were detected with SSI Salmonella typing sera. According to K-B drug susceptibility testing method published by USA clinical and Laboratory Standards Institute (CLSI), the antibiotics resistant phenotype of the positive strains were analyzed. Results: A total of 1 351 strains of non-typhi Salmonella were isolated, in which 811 were from males, 540 were from females. The ratio of men to women was 1.5∶1. Children and young adults were mainly affected. The pathogen isolation was mainly in May-October during a year. The 1 351 strains of non-typhi Salmonlla were divided into 58 serotypes. S. enteritidis, S. typhimurium, S. agona, S. derby, S. indiana, S. senftenberg and S. thompson ranked 1st-7th. The drug-resistance rate of the 1 351 strains was 46.1% to synthetic broad-spectrum penicillin ampicillin (AMP), 19.5% and 21.2% to the three generation cephalosporin ceftazidime (CAZ) and cefotaxime (CTX), 8.8% to the four generation cephalosporins cefepime (FEP), 58.7% to the one generation of quinolones nalidixic acid (NAL), 14.7% to the three generation fluoroquinolone ciprofloxacin (CIP) and norfloxacin (NOR), 25.0% and 35.6% to aminoglycoside antibiotic gentamicin (GEN) and streptomycin (STR), 35.4% to amphenicols (CHL), 31.7% to sulfonamide trimethoprim (TMP) and 37.8% to tetracycline (TET). Totally 879 strains were multidrug resistant (65.1%): 350 strains were resistant to 3-4 kinds of antibiotics (25.9%), 309 strains were resistant to 5-7 kinds of antibiotics (22.9%), 174 strains were resistant to 8-10 kinds of antibiotics (12.9%) and 48 strains were resistant to 11-12 kinds of antibiotics (3.6%). Conclusion: The serotypes of non-typhi Salmonella strains isolated from Henan province varied, some strains were resistant to 12 kinds of antibiotics commonly used in clinical treatment and the multidrug resistance has become serious.

[The etiological and molecular typing research of diarrheagenic Escherichia coli in Henan province in 2013].

OBJECTIVE: To analyze the distribution and pulsed field gel electrophoresis (PFGE) patterns of five kinds of diarrheagenic Escherichia coli (DEC) in infected diarrhea population of Henan province in 2013. METHODS: Gathering 1 037 strains of E. coli of 1 037 diarrhea patients from four sentinel hospitals of multi-pathogen monitoring system in Henan province in 2013. Stool samples were cultured with Mac agar plates and using KIA/MIU biochemical action as the preliminary method to identify E. coli strains; preparation of DNA template with thermal cracking method and using multiplex PCR to detect five kinds of DEC. According to molecular typing method published by the international PulseNet bacterial infectious disease monitoring network, the PFGE molecular characteristics of DEC strains were analyzed. RESULTS: 125 DEC positive strains were detected in 1 037 strains of E. coli, the total detection rate was 12.05%. 90 strains were enteroaggregative E.coli (EAEC), detection rate was 8.68% (n=90); 24 strains were enteropathogenic E.coli (EPEC), detection rate was 2.31%; 7 strains were enteroinvasive E.coli (EIEC), detection rate was 0.68%; 4 strains were enterotoxigenic E.coli (ETEC), detection rate was 0.39%; enterohemorrhagic E.coli (EHEC) was not detected. 639 cases of diarrhea samples were collected from male patients, 398 cases were from female patients, 94 positive cases were from male patients, the detection rate was 14.71%.The positive number of female cases were 31 cases, the detection rate was 7.79%. 97 positive cases were detected from 782 countryside cases and 28 positive cases were detected from 255 urban area cases, with detection rate 12.40% and 10.98% respectively. In 125 cases of DEC positive samples, children below 5 years old were 83 cases, accounting for 66.4%; 53 strains of EAEC were divided into 52 molecular patterns by digestion with XbaⅠ and pulsed field gel electrophoresis, each pattern contained 1-2 strains with similarity ranged from 66.3%-100%; 18 strains of EPEC were divided into 18 molecular patterns, each pattern contains 1 strain with similarity ranged from 72.6%-94.8%; 5 strains of EIEC were divided into 5 molecular patterns, each pattern contains 1 strain with similarity ranged from 71.9%-98.5%. 2 strains of ETEC were divided into 2 molecular patterns and similarity below 70%. CONCLUSION: Through the research we could find that four kinds of DEC as a pathogenic bacteria took an important component in pathogenic spectrum of bacterial diarrhea of Henan province in 2013. Four kinds of DEC carrying different virulence genes and taking multiple PFGE patterns showed diversity and complexity characteristics.

[Drug tolerance and PFGE molecular typing of Salmonella paratyphi A isolated in Dengfeng, Henan province, 2009-2015].

OBJECTIVE: To investigate the drug tolerance and PFGE patterns of Salmonella(S.)paratyphi A strains isolated from sentinel hospitals in Dengfeng, Henan province, during 2009-2015. METHODS: Venous blood samples were collected from paratyphoid patients and cultured in double phase blood culture bottle. Suspicious strains were identified and used for Salomonella. O antigen and H1/2 phase flagellum-induced serum agglutination test with API20E biochemical systems and SSI Salmonella typing sera. According to Salmonella molecular typing and K-B drug susceptibility testing method published by PulseNet China bacterial infectious disease monitoring network and USA Clinical and Laboratory Standards Institute, we analyzed the drug susceptibility and PFGE molecule characteristics of S. paratyphi A strains isolated from the patients. RESULTS: A total of 126 strains of S. paratyphi A were isolated from 248 blood samples, the antigen modes of them were 1, 2, 12:a:-. The resistance rate of 126 strains of S. paratyphi A was 83.3% to ampicillin; 29.4% to ceftazidime, 31.2% to cefotaxime, 17.5% to cefepime; 62.6% to nalidixic acid; 19.3% to ciprofloxacin, 26.4% to norfloxacin; 22.8% to gentamicin, 47.9% to streptomycin; 19.2% to chloramphenicol, 24.2% to methicillin benzyl ammonium, 58.6% to compound sulfamethoxazole and 46.7% to tetracycline. The 126 strains of S. paratyphi A had different levels of resistance to 8 kinds of antibiotics, 109 strains were multidrug resistant(86.5%), 9 strains were resistant to 2-3 kinds of antibiotics(7.1%), 76 strains were resistant to 5-8 kinds of antibiotics(60.3%), 17 strains were resistant to 9-10 kinds of antibiotics(13.5%), 7 strains were resistant to 11-12 kinds of antibiotics(5.6%). The 126 strains of S. paratyphi A were divided into 14 molecular patterns by digestion with XbaⅠand pulsed field gel electrophoresis. The antibiotics resistance to third generation cephalosporin(CAZ, CTX), one generation and three generation of quinolones(NAL, CIP, NOR)and aminoglycosides antibiotics(STR)showed an upward trend. Each pattern contained 1-98 strains with similarity ranged from 64.10% to 100.00%. PTYA 1, 6, 9 and 10 were the main PFGE belt types. CONCLUSION: The drug resistance of clinical isolates of S. paratyphi A was serious in Dengfeng, Henan province, PFGE patterns showed a diversity, but predominant patterns could also be found. The PFGE patterns of some strains had clustering and were related with their antidrug spectrums.