Physiological changes in serum procalcitonin concentrations in premature infants early after birth / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate serum procalcitonin (PCT) concentrations in premature infants with different gestational ages at different times after birth.</p><p><b>METHODS</b>A total of 217 neonates without infection, including 102 premature infants and 115 full-term infants, were enrolled in this study. The premature infants were further divided by gestational age into three subgroups: 30-32 weeks (n=30), 33-34 weeks (n=35) and 35-36 weeks (n=37). All the infants were studied to evaluate serum PCT concentrations at 0-12, 13-24, 25-36, 37-48, 49-72, 73-96, 97-120 and 121-144 hours after birth.</p><p><b>RESULTS</b>In the newborns, serum PCT concentrations increased gradually after birth, reached peak values at about 24 hours after birth, and then gradually declined and dropped to normal values for children at about 96 hours after birth. In the premature infants, serum PCT concentrations reached peak values at about 36 hours after birth, later than in the full-term infants, then declined slowly and dropped to levels similar to the full-term infants at 96 hours after birth. Serum PCT concentrations in the 30-32 week subgroup remained at low levels after birth, and increased gradually, later than in other premature infants, at 37-48 hours after birth.</p><p><b>CONCLUSIONS</b>Early after birth, neonates have a changing serum PCT concentration, increasing first and then decreasing. Peak serum PCT levels appear later in premature infants than in full-term infants. Serum PCT concentrations of premature infants with a gestational age of under 32 weeks remain at relatively low levels within 36 hours after birth.</p>

Relationship between time to positivity of blood culture with clinical characteristics and hospital mortality in patients with Escherichia coli bacteremia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies indicated that the time to positivity (TTP) of blood culture is a parameter correlating with degree of the bacteremia and outcome in patients with bloodstream infections caused by Escherichia coli (E. coli). The objective of this study was to further investigate the diagnostic and prognostic power of using TTP to predict E. coli bacteremia.</p><p><b>METHODS</b>A retrospective cohort study at two university hospitals was conducted. We retrieved all the medical records of those with E. coli bloodstream infection according to the records generated by their microbiology departments. Univariate and multivariate analyses were applied to identify clinical factors correlating with fast bacterial growth and significant prognostic factors for hospital mortality.</p><p><b>RESULTS</b>Medical records of 353 episodes of E. coli bacteremia diagnosed between January 1, 2007 and December 31, 2009 were retrieved in the investigation. Univariate analysis demonstrated that the TTP ≤ 7 hours group is associated with higher incidence of active malignancies (41.7% vs. 27.2%, P = 0.010), neutropenia (30% vs.14.3%, P = 0.007), primary bacteremia (55.0% vs. 33.4%, P = 0.002), and poorer outcome (hospital mortality 43.3% vs.11.9%, P = 0.000) than the TTP > 7 hours group. Multivariate analysis revealed that the significant predictors of hospital mortality, in rank order from high to low, were TTP (for TTP ≤ 7 hours, odds ratio (OR): 4.886; 95% confidence interval (CI): 2.572 - 9.283; P = 0.000), neutropenia (OR: 2.800; 95%CI: 1.428 - 5.490; P = 0.003), comedication of steroids or immunosuppressive agents (OR: 2.670; 95%CI: 0.971 - 7.342; P = 0.057).</p><p><b>CONCLUSIONS</b>Incidence of malignancies, neutropenia and primary bacteremia correlates with fast bacterial growth in patients with E. coli bacteremia. The parameter of TTP has been identified as a variable of highest correlation to hospital mortality and therefore can be potentially utilized as a mortality prognostic marker.</p>

Genotype distribution of extended-spectrum and AmpC ?-lactamases produced by Escherichia coli and Klebsiella pneumoniae in 10 teaching hospitals of China / 中国感染与化疗杂志

Objective To investigate the genotype distribution of extended-spectrum?-lactamases(ESBLs) and AmpC?-lacta- mases produced by Escherichia coli and Klebsiella pneumoniae in 10 teaching hospitals of China.Methods 90 clinical strains of E.coli and 61 strains of K.pneumoniae isolated in 2003 and confirmed to produce ESBLs were collected from 10 teaching hos- pitals in China.Analytical isoelectric focusing was used to measure the pI of the?-lactamases.Conjugation experiment was used to study the transfer of cefoxitin resistance.Plasmid-mediated AmpC enzyme genes were amplified and sequenced by multiplex polymerase chain reaction (MPCR).Results The prevalence of ESBL-producing E.coli and K.pneumoniae was about 50% in Wuhan,Nanjing and Jinan.The prevalence of ESBL-producing E.coli was lower than K.pneumoniae in Beijing.However,in other hospitals the prevalence of ESBL-producing E.coli was a little higher than K.pneumoniae.About 24.4% of ESBL-pro- ducing E.coli isolates and 19.4% of ESBL-producing K.pneumoniae isolates were resistant to cefoxitin.Cefoxitin-resistant i solate was identified in all hospitals except Shenyang.Major genotype of ESBL-producing isolates was CTX-M.The CTX-M-9 group was the most common group,followed by CTX-M-1.More K.pneumoniae isolates produced both ESBLs and AmpC en- zyme than E.coli.The genotype was CTX-M/DHA-1.The PCR results of 3 transconjugants producing both ESBLs and AmpC enzyme were the same as their donor isolates.Conclusions The genotype of ESBL-producing isolates is mainly CTX-M-9 group in these teaching hospitals.More K.pneumoniae isolates produced both ESBLs and AmpC enzyme than E.coli.Most of these isolates are due to geno type CTX-M/DHA-1,which can spread through plasmid.