ABSTRACT
Objective:To investigate the multilocus sequence typing feature of the virulence-associated genes of Staphylococcus aureus(S. aureus) separated from the clinical specimens of a multi-center cohort children in Guangzhou area. Methods:A total number of 412 Staphylococcus aureus strains isolated from 2 059 non-repeated fecal specimens of children by three groups′ researchers in Guangzhou Women and Children′s Medical Center from August 2018 to November 2018. While collecting specimens, patient clinical information is also properly collected and preserved. After extracting the DNA of the strain, the virulence-associated genes were detected by polymerase chain reaction (PCR), including the staphylococcal enterotoxin (SE) genes ( sea, seb, sec, sed, see) and the Panton-Valentine leucocidin-encoding gene ( pvl).The multi-locus sequence typing (MLST) method was performed to reveal the MLST feature of these genes and the statistical difference were examined by the the χ 2 test. Results:Among the 412 isolates of S. aureus, 256 strains (256/412, 62.1%) contains at least one SE gene. Among the enterotoxin gens, the sec (125/412, 30.3%), seb(98/412, 23.8%)and sea (66/412, 16.0%)genes were the three most prevalent members of SEs. The frequency of pvl gene in Staphylococcus aureus was 18.7%(77/412).Among them, the frequency of Staphylococcus aureus sea gene isolated from patients with gastroenteritis (58/319, 18.2%) was significantly higher than that from the non-gastroenteritis group (8/93, 8.6%)(χ2=4.912, P=0.027). The frequency of Staphylococcus aureus pvl gene isolated from the patients with pneumonia (8/21, 38.1%) was greater than that from the non-pneumonia group (6/47, 12.8%)(χ2=4.252, P=0.039). In addition, the virulence-associated gene of S. aureus was closely related to the specific ST type, 82.4% (28/34) of ST6 carried sea gene, all ST338 and ST59 carried seb gene, 96% (48/50) ST45 carried sec gene, and the pvl gene carrying rate of ST338 was 5/5. Conclusions:The SEA toxin produced by ST6 Staphylococcus aureus may be closely related to the diagnosis of gastroenteritis in children. The frequency of pvl virulence gene in Staphylococcus aureus in children with community-acquired pneumonia was higher than that in the non-pneumonia group, and closely related to the CC59.
ABSTRACT
Objective To analyze the clinical features and factors affecting prognosis for intracerebral hemorrhage (ICH) during pregnancy and postpartum.Methods A study of ICH was performed on 61 women in Beijing Tiantan Hospital,Capital Medical University between January 1997 and December 2014,and all cases were diagnosed with cerebral hemorrhage or subarachnoid hemorrhage during pregnancy or six weeks after delivery with CT or MRI after exclusion of ICH due to craniocerebral trauma.The subjects were divided into surgery (n=26) and conservative treatment (n=35) groups according to different ways of treatment;pregnancy associated problems (n=11) and cerebrovascular diseases groups according to the aetiology of ICH;low (n=13) and high score group (n=48) according their Glasgow score at the first visit;and short clinical onset to diagnosis time (O-D time) group (≤ 24 h,n=33) and long O-D time (＞24 h) group (n=28).We compared the maternal clinical features and prognosis between different groups with t,Mann-Whitney U or Chi-square tests.A stratified logistic regression was used to assess the effect of factors affecting the prognosis.Results The average gestational age at the onset of ICH of the 61 cases was (28.8±8.3) weeks (6-40 weeks),the Glasgow score was (11.3±4.8),the median O-D time was 24.0 h,the modified Rankin scale (mRS) was 2.7,and 14 maternal deaths were reported (23.0％).Among the 61 women,three were terminated in early trimester,12 terminated in second trimester,and the rest 46 delivered in late term among which two fetal deaths,44 live births,and four neonatal deaths.Thus the perinatal infant death rate was 13.0％ (6/46).The difference of maternal clinical features and prognosis between the surgery and conservative treatment group was not significant (all P＞0.05).However,comparison between the cerebrovascular disease and pregnancy associated diseases group showed the latter had a lower Glasgow score and Apgar score [12.2(3.0) vs 7.5(12.0),(8.9±1.9) vs (7.2±2.6)],the higher mRS [2.4(2.0) vs 3.9(5.0)] and gestational age [(27.7±8.4) vs (34.9±4.1)],maternal mortality rate [14.0％ (7/50) vs 7/11] and perinatal death rate [5.4％ (2/37) vs 4/11] (t or x2=-3.09,-2.34,1.93,1.17,2.12 and 1.78,all P＜0.05).For women with low Glasgow score,the median O-D time was shorter than that of higer Glasgow score group (8.0 vs 48.0 h),the mRs and maternal mortality rate were higher 4.9(2.5) vs 3.1(2.0);9/13 vs 10.4％(5/48),t,U or x2=426.00,5.77 and 19.14,all P＜0.05].The short O-D time group showed lower Glasgow score and average Apgar score of the newborns than the long O-D time group [9.8(11.3) vs 13.2(2.0),(7.9±2.7) vs (9.2±0.9);t,U or x2=-2.91 and-2.23,both P＜0.05].The Glasgow scores was negatively associated with the mRs (OR=-0.26,95％CI:-0.16 to-0.05).In particular,O-D time (OR=0.03,95％CI:0.00-0.66) and pre-eclampsia (OR=0.33,95％CI:0.12-0.26) were both positively related to maternal mRs.However,the Glasgow scores,surgical treatment,O-D time and concomitant pre-eclampsia were irrelevant to the death ofperinatal infants (all P＞0.05).Conclusions The prognosis is poor in women with ICH during pregnancy or postnatal period whose Glasgow score was low or O-D time was long,or the ICH occurred due to pre-eclampsia.Antenatal care should be strengthened and early identification and diagnosis might improve the prognosis.