OBJECTIVETo study the pathogen distribution and risk factors of nosocomial infection in very preterm infants, as well as the risk of adverse outcomes.

METHODSA retrospective analysis was performed for the clinical data of 111 very preterm infants who were born between January and December, 2016 and had a gestational age of <32 weeks and a birth weight of <1 500 g. According to the presence or absence of nosocomial infection after 72 hours of hospitalization, the infants were divided into infection group and non-infection group. The infection group was analyzed in terms of pathogenic bacteria which caused infection and their drug sensitivity. A multivariate logistic regression analysis was used to investigate the potential risk factors and risk of adverse outcomes of nosocomial infection in very preterm infants.

RESULTSGram-negative bacteria were the main pathogens for nosocomial infection in very preterm infants and accounted for 54%, among which Pseudomonas aeruginosa was the most common one; the following pathogens were fungi (41%), among which Candida albicans was the most common one. The drug sensitivity test showed that Gram-negative bacteria were highly resistant to β-lactam and carbapenems and highly sensitive to quinolones, while fungi had low sensitivity to itraconazole and high sensitivity to 5-fluorocytosine and amphotericin B. Early-onset sepsis, duration of peripherally inserted central catheter, steroid exposure, and duration of parenteral nutrition were risk factors for nosocomial infection in very preterm infants (P<0.05). Compared with the non-infection group, the infection group had significantly higher risks of pulmonary complications (P<0.05), as well as a significantly longer length of hospital stay and a significantly higher hospital cost (P<0.001).

CONCLUSIONSNosocomial infection in very preterm infants is affected by various factors and may increase the risk of adverse outcomes. In clinical practice, reasonable preventive and treatment measures should be taken with reference to drug sensitivity, in order to improve the prognosis of very premature infants.

Cross Infection ; epidemiology ; etiology ; microbiology ; Female ; Gram-Negative Bacteria ; drug effects ; isolation & purification ; Health Care Costs ; Humans ; Infant, Newborn ; Infant, Premature ; Length of Stay ; Logistic Models ; Male ; Microbial Sensitivity Tests ; Retrospective Studies ; Risk Factors

No abstract available.
Aged ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Cefotaxime/analogs & derivatives/therapeutic use ; Cholangiopancreatography, Endoscopic Retrograde ; Gallstones/surgery ; Gram-Negative Anaerobic Bacteria/drug effects/genetics/*isolation & purification ; Gram-Negative Bacterial Infections/*diagnosis/drug therapy/microbiology ; Humans ; Male ; Metronidazole/therapeutic use ; Microbial Sensitivity Tests ; RNA, Ribosomal, 16S/chemistry/genetics/metabolism ; Sequence Analysis, DNA ; Tomography, X-Ray Computed

No abstract available.
Anti-Bacterial Agents/*pharmacology ; Azabicyclo Compounds/*pharmacology ; Bacterial Proteins/genetics ; Ceftazidime/*pharmacology ; Cephalosporins/*pharmacology ; DNA, Bacterial/genetics/metabolism ; Drug Resistance, Bacterial/*drug effects ; Gram-Negative Bacteria/drug effects/*isolation & purification ; Humans ; Microbial Sensitivity Tests ; Penicillanic Acid/*analogs & derivatives/pharmacology ; Pseudomonas aeruginosa/drug effects/isolation & purification ; Real-Time Polymerase Chain Reaction

BACKGROUND: We evaluated the reliability and accuracy of the combined use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) bacterial identification and Vitek 2 antimicrobial susceptibility testing (AST) for bacteria from positive blood culture bottles. METHODS: Direct identification and AST were performed in parallel to the standard methods in monomicrobial positive blood culture bottles. In total, 254 isolates grown on aerobic and/or anaerobic bottles were identified with MALDI-TOF Vitek MS (bioMerieux, France), and 1,978 microorganism/antimicrobial agent combinations were assessed. For isolates from anaerobic bottles, an aliquot of the culture broth was centrifuged, washed, and filtered through a nylon mesh. For isolates from aerobic/pediatric bottles, a lysis step using 9.26% ammonium chloride solution and 2% saponin solution was included. RESULTS: The overall correct identification rate was 81.8% (208/254) and that for gram-positive/gram-negative isolates was 73.9%/92.6%, respectively, and it was 81.8%, 87.6%, and 57.9% for isolates from aerobic, anaerobic, and pediatric bottles, respectively. Identification was not possible in 45 cases, and most of these isolates were streptococci (N=14) and coagulase-negative staphylococci (N=11). Misidentification occurred only in one case. Compared with standard methods, direct AST showed 97.9% (1,936/1,978) agreement with very major error of 0.25%, major error of 0.05%, and minor error of 1.8%. CONCLUSIONS: This simple and cost-effective sample preparation method gives reliable results for the direct identification and AST of bacteria. For the identification of streptococci and coagulase-negative staphylococci, the method should be further improved.
Adult ; Ammonium Chloride/chemistry ; Anti-Infective Agents/*pharmacology ; Child ; Gram-Negative Bacteria/drug effects/*isolation & purification/metabolism ; Gram-Positive Bacteria/drug effects/*isolation & purification/metabolism ; Humans ; Reagent Kits, Diagnostic ; Saponins/chemistry ; *Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

OBJECTIVETo analyze the detection, drug resistance, and status of infection of Acinetobacter baumannii (AB) in burn ICU during 3 years.

METHODSA total of 2 010 specimens of wound secretion, blood, venous catheter attachment, sputum, stool and urine were collected from 505 burn patients hospitalized in our burn ICU from January 2011 to December 2013, and bacterial culture was performed. Pathogens were identified by automatic microorganism identifying and drug sensitivity analyzer. Drug resistance of all the obtained AB to 16 antibiotics commonly used in clinic, including cefoperazone/sulbactam, polymyxin, etc., was tested with K-B paper disk diffusion method. Patients with AB infection were ascertained. The WHONET 5.6 software was used to analyze the distribution of pathogens during 3 years, the isolation of AB with different sources and the status of drug resistance of AB to 16 antibiotics each year, and the status of patients with AB infection, and their outcome.

RESULTSA total of 961 strains of pathogens were isolated, among which 185 (19.25%) strains were Gram positive cocci, 728 (75.75%) strains were Gram negative bacilli, and 48 (4.99%) strains were fungi. A total of 172 strains of AB were isolated, ranking the second place among all the detected pathogens, with 67 (38.95%) strains from wound secretion, 11 (6.40%) strains from blood, 23 (13.37%) strains from venous catheter attachment, and 71 (41.28%) strains from sputum, no AB strain was isolated from feces or urine. The AB strains were found sensitive to polymyxin and with relatively low drug resistance rate to minocycline, while the drug resistance rates were over 80.0% to the other 14 antibiotics commonly used in clinic in 2013. AB culture of wound secretion was positive in 27 patients. Among them, 7 patients suffered from wound infection, and the wound infection was caused by AB in 1 out of the 7 patients. AB culture of blood was positive in 7 patients. Among them, 3 patients suffered from bloodstream infection, and the infection was due to AB invasion in 1 out of the 3 patients. AB culture of venous catheter attachment was positive in 20 patients. Among them, 8 patients suffered from bloodstream infection, and the infection was due to AB invasion in 1 out of the 8 patients. AB culture of sputum was positive in 35 patients. Among them, 13 patients suffered from ventilatory associated pneumonia, and 2 out of the 13 patients were diagnosed as AB infection. A total of 69 patients were AB culture positive, among them 64 patients were cured, 2 patients were transferred to other hospitals, and 3 patients died, with the mortality rate of 4.35%.

CONCLUSIONSAB in our burn ICU has a high detection rate and extensive drug resistance in above-mentioned 3 years. However, AB was mainly colonized in patients with extensive burns with a low mortality rate.

Acinetobacter Infections ; drug therapy ; epidemiology ; microbiology ; Acinetobacter baumannii ; drug effects ; isolation & purification ; Anti-Bacterial Agents ; pharmacology ; Burns ; microbiology ; Cross Infection ; Drug Resistance ; Gram-Negative Bacteria ; isolation & purification ; Humans ; Intensive Care Units ; Microbial Sensitivity Tests

The trends and types of carbapenemase-producing Gram-negative bacilli were analyzed from clinical specimens collected between 2005 and 2012 at a Korean teaching hospital. The proportions of carbapenem-resistant Acinetobacter spp. increased markedly to 66%. Metallo-beta-lactamase producers significantly decreased and the majority shifted from the bla(VIM-2) type to the bla(IMP-1) type.
Acinetobacter/classification/drug effects/*enzymology ; Acinetobacter Infections/drug therapy ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins ; Carbapenems/*pharmacology ; Drug Resistance, Microbial ; Gram-Negative Bacteria/*drug effects/enzymology/isolation & purification ; Humans ; Incidence ; Microbial Sensitivity Tests/trends ; Population Surveillance ; Pseudomonas/classification/drug effects/enzymology ; Republic of Korea/epidemiology ; beta-Lactamases/biosynthesis/*drug effects

OBJECTIVETo study the pathogens, drug sensitivity and risk factors for ventilator-associated pneumonia (VAP) in neonates.

METHODSRetrospective analysis was performed on the clinical data of 401 neonates who were admitted to the neonatal intensive care unit and received mechanical ventilation for 48 hours or longer from January 2008 to February 2012. Eighty-five of the 401 neonates suffered VAP.

RESULTSThe main pathogens for VAP were Gram-negative bacteria (97%), including Klebsiella pneumoniae (51%), Acinetobacter baumannii (17%) and Escherichia coli (12%) as the three most frequent ones. The drug sensitivity test showed that these pathogens developed resistance to amoxicillin, amoxicillin/clavulanic acid, piperacillin, ceftazidime, cefazolin, and cefotaxime, with a susceptibility rate of below 15%, and demonstrated decreased sensitivity to imipenem and meropenem, with a susceptibility rate of below 75%. The independent risk factors for neonatal VAP included birth weight (OR=1.399, P<0.05), duration of mechanical ventilation (OR=1.966, P<0.01), length of hospital stay (OR=1.812, P<0.01), times of tracheal intubation (OR=2.056, P<0.01), and 1 min Apgar score (OR=2.146, P<0.01).

CONCLUSIONSThe incidence of neonatal VAP is influenced by many factors. The main pathogens for neonatal VAP are Gram-negative bacteria and antibacterial agents should be properly used according to drug sensitivity test results. Comprehensive prevention and control measures should be taken to reduce the incidence of VAP.

Female ; Gram-Negative Bacteria ; drug effects ; isolation & purification ; Humans ; Infant, Newborn ; Logistic Models ; Male ; Microbial Sensitivity Tests ; Pneumonia, Ventilator-Associated ; etiology ; microbiology ; Risk Factors

OBJECTIVETo determine the frequency distribution and antibiotic resistance of pathogens isolated from the cerebrospinal fluid samples of children with bacterial meningitis (BM) and to provide a basis for the timely and effective treatment of childhood BM.

METHODSRetrospective analysis was performed on pathogens isolated from 5097 cerebrospinal fluid samples collected from children in Kunming Children's Hospital between January 2008 and June 2012, as well as drug sensitivity test results. Kirby-Bauer antibiotic testing was used to analyze the sensitivity of these pathogens to commonly used antibiotics.

RESULTSA total of 116 pathogen strains were detected from the 5097 cerebrospinal fluid samples, including 77 (66.4%) Gram-positive strains, 30 (25.9%) Gram-negative strains, and 9 (7.8%) fungal strains, with a positive rate of 2.28%. The six most frequently isolated pathogens were Staphylococcus epidermidis (32 strains, 27.6%), Streptococcus pneumoniae (15 strains, 12.9%), Escherichia coli (15 strains, 12.9%), Staphylococcus haemolyticus (9 strains, 7.8%), Cryptococcus neoformans (8 strains, 6.9%) and Staphylococcus aureus (6 strains, 5.2%). Coagulase-negative staphylococci was the predominant pathogen in neonates and young infants with BM, and its sensitivity rates to penicillin, erythromycin and clindamycin were lower than 40%. Streptococcus pneumoniae had a penicillin sensitivity rate of 13.4%, while sensitivity rates to erythromycin and clindamycin reached 60.0%. No Staphylococcus and Streptococcus pneumoniae pathogens resistant to vancomycin were found. Gram-negative bacilli had relatively high sensitivity rates to imipenem, meropenem, cefoperazone/sulbactam and cefepime.

CONCLUSIONSGram-positive cocci are the predominant pathogens for childhood BM over the past five years. The detected pathogens develop high resistance to commonly used antibiotics. To prevent misdiagnosis, careful attention should be paid to BM caused by Cryptococcus neoformans.

Child ; Child, Preschool ; Drug Resistance, Bacterial ; Female ; Gram-Negative Bacteria ; drug effects ; isolation & purification ; Gram-Positive Cocci ; drug effects ; isolation & purification ; Humans ; Infant ; Infant, Newborn ; Male ; Meningitis, Bacterial ; cerebrospinal fluid ; drug therapy ; microbiology ; Retrospective Studies

OBJECTIVE: To investigate the change of pathogen distribution and antibiotic resistance of pathogens isolated from in-patients with hospital acquired pneumonia (HAP) in the Department of Respiratory Medicine Intensive Care Unit (RICU) of Xiangya Hospital in 2005 and in 2011, and to provide reasonable anti-infectious strategy. METHODS: The positive susceptibility test of sputum (bronchial secretions) culture was done in patients with HAP in RICU of Xiangya Hospital in 2005 and in 2011, and the distribution feature and antibiotic resistance were compared. RESULTS: 1) In the two years, the main pathogen in HAP patients was Gram negative bacteria (infection rate was 68.07% and 65.21% in 2005 and in2011 respectively). The primary pathogenic bacteria were changed, and Acinetobacter baumanii became the most common Gram negative bacterium which replaced Pseudomonas aeruginosa, with infection rate 6.81% in 2005 to 40.87% in 2011. The infection rate of Pseudomonas aeruginosa reduced from 20.42% in 2005 to 15.60% in 2011. Haemophilus influenzae was rare. Staphylococcus aureus became the primary Gram positive bacteria, and its infection rate increased from 1.57% in 2005 to 4.83% in 2011, all of which were methicillin-resistant Staphylococcus aureus (MRSA). Saccharomyces albicans' positive culture rate increased significantly. 2) Compared with in 2005, the antibiotic resistance of pathogen isolated from the HAP pationts changed a lot in 2011: increased antibiotic resistance rate and decreased sensitivity to many antibiotics. Pseudomonas aeruginosa was only relatively susceptible to meropenem, cefoperazone sulbactam, ceftazidime, cefpodoxime, and andamicaxin in 2011. The resistance rate of Pseudomonas aeruginosa to levofloxacin, cyclopropane, amicacin, gentamicin, meropenem, cematrixone, and piperacilintazobactam increased obviously (P<0.05). Compared with 2005, Acinetobacter baumanii was totally susceptible to polymyxin and relatively susceptible to sulbactam, but it was almost completely resistant to Aminoglycoside antibiotics in 2011, with significant difference (P<0.01). CONCLUSION The main pathogen of HAP patients in RICU was Gram negative bacteria, with increased infection rate of Staphylococcus aureus and fungus. There is change pathogen distribution and antibiotic resistance, and the clinical initial experimental antibiotic therapy may be influenced. It is important to use antibiotics more rationally to delay the antibiotic resistance.
Acinetobacter baumannii ; drug effects ; isolation & purification ; Cross Infection ; microbiology ; Drug Resistance, Bacterial ; Female ; Gram-Negative Bacteria ; drug effects ; isolation & purification ; Humans ; Intensive Care Units ; Male ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; isolation & purification ; Pneumonia ; etiology ; microbiology ; Respiratory Tract Diseases ; complications ; Saccharomyces ; drug effects ; isolation & purification ; Staphylococcus aureus ; drug effects ; isolation & purification

OBJECTIVETo study common pathogens and their antibiotic susceptibility as well as clinical characteristics of neonatal pneumonia.

METHODSA retrospective study on neonatal pneumonia was performed. The study investigated antibiotic susceptibility of four common pathogens (339 strains) that caused neonatal pneumonia. Clinical characteristics of the newborns with pneumonia were analyzed. Of the 339 strains, 185 were isolated from bronchial secretions, 72 from blood samples, and 82 with positive results of both samples.

RESULTSFour hundred and seventy-four neonates with pneumonia presented positive results of bacterial culture. the most common pathogens Staphylococcus aureus (21.9%), Escherichia coli (19.2%), Klebsiella pneumoniae (19.0%) and Enterobacter cloacae (11.4%). The birth weight of newborns infected with Staphylococcus aureus was generally normal, and the time of hospital admission was later (after 24 hours of life). In contrast, the newborns with gram-negative bacterial infection, especially Klebsiella pneumoniae infection, had lower birth weights and early time of hospital admission (within 24 hours of life). Nearly more than 50% gram-negative bacteria were resistant to second, third and forth generation cephaloporins.

CONCLUSIONSGram-negative bacteria are predominant pathogens of neonatal pneumonia. Neonatal pneumonia caused by gram-negative bacteria is common in newborns with low birth weight and its onset time is relatively earlier. Gram-negative bacteria that cause neonatal pneumonia are highly resistant to cephaloporins.

Adult ; Birth Weight ; Drug Resistance, Bacterial ; Female ; Gram-Negative Bacteria ; drug effects ; isolation & purification ; Humans ; Infant, Newborn ; Male ; Maternal Age ; Microbial Sensitivity Tests ; Pneumonia ; microbiology ; Retrospective Studies