Ochrobactrum Anthropi; an Unusual Cause of Bacteremia and Pneumonia: A Case Report and a Brief Review of the Literature.

Background: Ochrobactrum anthropi spp. is a non-enteric, aerobic gram-negative bacillus that has been reported to cause sepsis and occasionally bacteremia in both immunocompetent and immunocompromised hosts. This bacterium is capable of surviving in various habitats, but due to its affinity for aqueous environments, O. anthropi is hypothesized to have an affinity for indwelling plastic devices and other foreign bodies.

Case Presentation: We report a case of a 66 y/o male with a history of polysubstance abuse disorder admitted for toxic metabolic encephalopathy and found to have bronchopneumonia and bacteremia secondary to O. anthropi infection resulting in sepsis and cardiopulmonary arrest.

Discussion: Ochrobactrum spp. is an unusual pathogen of low virulence and has been noted to cause bacteremia and occasionally sepsis in both immunocompetent and immunosuppressed patients. Isolation of this pathogen in the appropriate setting should be considered a true pathogen and treated as such to avoid sequela of this infection.

Conclusion: This case report and literature review suggest that Ochrobactrum anthropi appears more frequently as a pathogen in nosocomial infections than suggested in the literature.

The First Lethal Infection by Oligella ureolytica: A Case Report and Review of the Literature.

Oligella ureolytica is a Gram-negative bacillus, a member of the Alcaligenaceae family, that had never previously been reported as lethal. Herein, a case of fatal infection caused by Oligella ureolytica in an elderly woman with suspected bladder cancer is reported. The species identification was confirmed through Sanger sequencing of the bacterial 16S rRNA sequence and compared to published sequences for phylogenetic analysis. Initial antibiotic therapy with ceftriaxone and oxacillin was initiated but had to be switched due to resistance. Cefepime in combination with metronidazole was administered, unfortunately failing to prevent the patient's death. Further studies are needed to explore additional factors influencing clinical outcomes in Oligella ureolytica infections.

An Unusual Case of Escherichia Coli Meningitis in an Immunocompetent Adult.

Spontaneous meningitis caused by Gram-negative bacilli is rare in adults. It typically occurs after a neurosurgical procedure or head injury but may also be related to the presence of a neurosurgical device, cerebrospinal fluid (CSF) leak syndrome, or seen in immunosuppressed patients. Escherichia coli (E. coli) is the leading cause of Gram-negative bacilli meningitis. We describe the case of a 47-year-old man who was hospitalized for spontaneous, community-acquired E. coli meningitis, which is unusual to see in an immunocompetent adult. CSF analysis was consistent with bacterial meningitis; his blood culture was positive for E. coli. Within 24 hours of initiation of antibiotics, his status improved.

Legionella-Induced Hepatitis: A Case Report.

Legionnaires' disease is caused by a potentially life-threatening infection with the opportunistic Gram-negative bacilli species Legionella pneumophila, which is transmitted via inhalation or aspiration of water droplets. Legionnaires' commonly presents as atypical community-acquired pneumonia with accompanying diarrhea. Although hepatic and renal involvement are relatively uncommon, in this report, we present a case of Legionella pneumonia with acute hepatitis.

Guidelines for the diagnosis, treatment, prevention and control of infections caused by carbapenem-resistant gram-negative bacilli.

The dissemination of carbapenem-resistant Gram-negative bacilli (CRGNB) is a global public health issue. CRGNB isolates are usually extensively drug-resistant or pandrug-resistant, resulting in limited antimicrobial treatment options and high mortality. A multidisciplinary guideline development group covering clinical infectious diseases, clinical microbiology, clinical pharmacology, infection control, and guideline methodology experts jointly developed the present clinical practice guidelines based on best available scientific evidence to address the clinical issues regarding laboratory testing, antimicrobial therapy, and prevention of CRGNB infections. This guideline focuses on carbapenem-resistant Enterobacteriales (CRE), carbapenem-resistant Acinetobacter baumannii (CRAB), and carbapenem-resistant Pseudomonas aeruginosa (CRPA). Sixteen clinical questions were proposed from the perspective of current clinical practice and translated into research questions using PICO (population, intervention, comparator, and outcomes) format to collect and synthesize relevant evidence to inform corresponding recommendations. The grading of recommendations, assessment, development and evaluation (GRADE) approach was used to evaluate the quality of evidence, benefit and risk profile of corresponding interventions and formulate recommendations or suggestions. Evidence extracted from systematic reviews and randomized controlled trials (RCTs) was considered preferentially for treatment-related clinical questions. Observational studies, non-controlled studies, and expert opinions were considered as supplementary evidence in the absence of RCTs. The strength of recommendations was classified as strong or conditional (weak). The evidence informing recommendations derives from studies worldwide, while the implementation suggestions combined the Chinese experience. The target audience of this guideline is clinician and related professionals involved in management of infectious diseases.

Guidelines for the diagnosis, treatment, prevention and control of infections caused by carbapenem-resistant gram-negative bacilli

The dissemination of carbapenem-resistant Gram-negative bacilli (CRGNB) is a global public health issue. CRGNB isolates are usually extensively drug-resistant or pandrug-resistant, resulting in limited antimicrobial treatment options and high mortality. A multidisciplinary guideline development group covering clinical infectious diseases, clinical microbiology, clinical pharmacology, infection control, and guideline methodology experts jointly developed the present clinical practice guidelines based on best available scientific evidence to address the clinical issues regarding laboratory testing, antimicrobial therapy, and prevention of CRGNB infections. This guideline focuses on carbapenem-resistant Enterobacteriales (CRE), carbapenem-resistant Acinetobacter baumannii (CRAB), and carbapenem-resistant Pseudomonas aeruginosa (CRPA). Sixteen clinical questions were proposed from the perspective of current clinical practice and translated into research questions using PICO (population, intervention, comparator, and outcomes) format to collect and synthesize relevant evidence to inform corresponding recommendations. The grading of recommendations, assessment, development and evaluation (GRADE) approach was used to evaluate the quality of evidence, benefit and risk profile of corresponding interventions and formulate recommendations or suggestions. Evidence extracted from systematic reviews and randomized controlled trials (RCTs) was considered preferentially for treatment-related clinical questions. Observational studies, non-controlled studies, and expert opinions were considered as supplementary evidence in the absence of RCTs. The strength of recommendations was classified as strong or conditional (weak). The evidence informing recommendations derives from studies worldwide, while the implementation suggestions combined the Chinese experience. The target audience of this guideline is clinician and related professionals involved in management of infectious diseases.

Guidelines for the diagnosis, treatment, prevention and control of infections caused by carbapenem-resistant gram-negative bacilli [Pré-print]

The dissemination of carbapenem-resistant Gram-negative bacilli (CRGNB) is a global public health issue. CRGNB isolates are usually extensively drug-resistant or pandrug-resistant, resulting in limited antimicrobial treatment options and high mortality. A multidisciplinary guideline development group covering clinical infectious diseases, clinical microbiology, clinical pharmacology, infection control, and guideline methodology experts jointly developed the present clinical practice guidelines based on best available scientific evidence to address the clinical issues regarding laboratory testing, antimicrobial therapy, and prevention of CRGNB infections. This guideline focuses on carbapenem-resistant Enterobacteriales (CRE), carbapenem-resistant Acinetobacter baumannii (CRAB), and carbapenem-resistant Pseudomonas aeruginosa (CRPA). Sixteen clinical questions were proposed from the perspective of current clinical practice and translated into research questions using PICO (population, intervention, comparator, and outcomes) format to collect and synthesize relevant evidence to inform corresponding recommendations. The grading of recommendations, assessment, development and evaluation (GRADE) approach was used to evaluate the quality of evidence, benefit and risk profile of corresponding interventions and formulate recommendations or suggestions. Evidence extracted from systematic reviews and randomized controlled trials (RCTs) was considered preferentially for treatment-related clinical questions. Observational studies, non-controlled studies, and expert opinions were considered as supplementary evidence in the absence of RCTs. The strength of recommendations was classified as strong or conditional (weak). The evidence informing recommendations derives from studies worldwide, while the implementation suggestions combined the Chinese experience. The target audience of this guideline is clinician and related professionals involved in management of infectious diseases.

Successful Treatment of Ventriculitis Caused by MDR/XDR Gram-Negative Bacillus Using Ceftazidime/Avibactam: Case Series and Literature Review.

BACKGROUND: Central nervous system (CNS) infections caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacillus, including carbapenem-resistant Enterobacteriaceae (CRE) and Pseudomonas aeruginosa, are associated with high mortality rates. Clinical trials of ceftazidime/avibactam (CAZ/AVI) on infections of other systems indicate that they are effective against these infections. However, clinical studies on the efficacies of CAZ/AVI in the treatment of CNS infections have not been done. CASE PRESENTATION: We evaluated 3 patients diagnosed with MDR/XDR Gram-negative bacillus-associated CNS infections, and effectively treated with CAZ/AVI. Moreover, we performed literature reviews. Before the onset of CNS infections, the 3 patients were subjected to neurosurgical operations, treated with mechanical ventilation, long-term intensive care unit therapy, and various antibiotics. By intravenously administering CAZ/AVI, combined with another antibiotic, the MDR/XDR K. pneumoniae and P. aeruginosa associated ventriculitis was effectively treated in the 3 patients. CONCLUSION: CAZ/AVI is a viable treatment option for CNS infections caused by MDR/XDR Gram-negative bacteria.

Wohlfahrtiimonas chitiniclastica Bloodstream Infection Due to a Maggot-infested Wound in a 54-Year-Old Male.

We report a case of Wohlfahrtiimonas chitiniclastica bacteremia and sepsis, in the setting of lower limb wounds with maggot infestation. This is the first documented infection by this organism in the Australasia/Pacific region, identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry and 16S ribosomal ribonucleic acid sequencing. Clinicians should be aware of this emerging pathogen.

Intra-abdominal infection due to gram-negative bacilli:an analysis of 478 cases / 中国感染与化疗杂志

Objective To investigate the epidemiological and etiological characteristics of gram-negative bacilli (GNB) isolated from patients with intra-abdominal infection (IAI). Methods The patients with abdominal infection were identified retrospectively during the period from 2011 to 2015. The clinical and microbiological data were analyzed by WHONET 5.6 and SPSS 20.0. Results A total of 478 cases of IAI [hospital-acquired (HA) 290 cases, community-acquired (CA) 188 cases] were included in this analysis. CA-IAI patients at low risk were associated with significantly better outcome, and lower acute physiology and chronic health evaluation (APACHE) Ⅱ score and sequential organ failure assessment (SOFA) score than the CA-IAI and HA-IAI patients at high risk. The most common gram-negative bacillus isolated from intra-abdominal infections was E. coli and K. pneumoniae. The prevalence of ESBLs-producing E. coli and K. pneumoniae isolates was 75.8％ and 35.8％, respectively. The E. coli isolates remained highly susceptible to amikacin, piperacillin-tazobactam, and carbapenems during the 5-year period, while the K. pneumoniae isolates showed poorer susceptibility to ampicillin-sulbactam. Conclusions The prevalence of ESBLs-producing GNB is increasing in the patients with IAI. Such isolates were resistant to commonly used antimicrobial agents, but generally susceptible to carbapenems. It is important to strengthen the monitoring of antimicrobial resistance in IAIs, and choose antimicrobial therapy rationally based on the results of antimicrobial susceptibility test.

Risk factors and outcomes for the acquisition of carbapenem-resistant Gram-negative bacillus bacteremia: A retrospective propensity-matched case control study.

BACKGROUND/PURPOSE: A substantial number of carbapenem-resistant Gram-negative bacilli (CR GNB) have been identified among the etiologic multidrug-resistant GNB in healthcare-associated infections. For achieving a better therapeutic outcome by minimizing inappropriate empirical antibiotic treatment before blood culture and susceptibility testing results are available, it is very important to identify patients who are at risk for the development of CR GNB bacteremia. METHODS: Retrospective analysis of propensity-score matched (PSM) adult patients with CR GNB bacteremia (PSM-group 1 [n = 95]) and those with non-CR GNB bacteremia (PSM-group 2 [n = 190]). RESULTS: PSM-group 1 was found to a significantly longer length of hospital stay (27 vs. 18 days; p < 0.001) after emerging GNB bacteremia and a higher 30-day all-cause mortality rate (27.4% vs. 5.8%; p < 0.001), when compared with PSM-2 group. Independent risk factors for the acquisition of CR GNB bacteremia were previous exposure to an antipseudomonal penicillin (odds ratio [OR] = 3.58; 95% confidence interval [CI] = 1.30-9.90), an antipseudomonal cephalosporin (OR = 3.49; 95% CI = 1.09-11.24), and a carbapenem (OR = 3.60; 95% CI = 1.37-9.47), and longer length of hospital stay before the development of GNB bacteremia (OR = 1.03; 95% CI = 1.01-1.05). CONCLUSION: Risk factors for acquisition of CR GNB bacteremia identified in this study each may serve as a reminder alerting clinicians to hospitalized patients at risk for CR GNB bacteremia requiring appropriate antibiotic coverage, and in these circumstances, combined antibiotics may be used until antimicrobial de-escalation/adjustment is clearly indicated by the subsequently identified pathogenic GNB and its susceptibility profile.

Diagnostic value of combined detection of inflammatory indicators in bloodstream infection with different pathogenic bacteria / 中国感染控制杂志

Objective To investigate the diagnostic value of combined detection of procalcitonin (PCT), C-reactive protein (CRP), white blood cell (WBC), and neutrophil percentage (NEU%) in bloodstream infection with gram-positive coccus(G+), gram-negative bacillus (G-)and fungus.Methods Detection results of positive blood culture of 389 patients in a hospital between January 2014 and December 2015 were analyzed retrospectively, according to the results of blood culture, patients were divided into G+ coccus, G-bacillus and fungal bloodstream infection groups, inflammatory indicators of different groups of patients were compared.Results Mann-Whitney U test revealed that PCT level of G-infection group was higher than that of G+ and fungal infection group (comparison between G-infection group and G+ infection group : Z=-2.68,P<0.01;comparison between G-infection group and fungal infection group: Z=-2.46,P<0.05).If PCT≥0.5 ng/mL, CRP≥5.0 mg/L, NEU%≥70% and WBC≥10×109/L were as the cut-off point, statistical analysis revealed the positive rate of PCT in G-infection group was higher than that in G+ and fungal infection group(comparison between G-infection group and G+ infection group:χ2=5.94,P<0.05;comparison between G-infection group and fungal infection group:χ2=7.721,P<0.01);the positive rate of CRP in G-infection group was higher than that in G+ infection group (χ2=5.03,P<0.05).Binary logistic regression was adopted to analyze the efficacy of four indicators for the differentiation of bloodstream infection caused by G+ coccus, G-bacillus, and fungus, only PCT had significant difference in the identification of bloodstream infection caused by G-bacillus, G+ coccus and fungus(P<0.01).Conclusion PCT has high accuracy in differentiating G-bacillus, G+ coccus, and fungus of blood culture, dynamic monitoring of PCT combined with detection results of CRP, WBC, and NEU%, patient's condition can be judged rapidly, and antimicrobial agents can be used rationally, so the mortality of patients with bloodstream infection can be reduced.

Correlation Analysis of the Detection Rate of Carbapenems-resistant Gram-negative Bacillus with Drug Consumption in Our Hospital / 中国药房

OBJECTIVE:To provide reference for standardizing the clinical use of carbapenem antibiotics and controlling drug-resistant bacteria infection. METHODS:The detection of 3 kinds of carbapenems-resistant Gram-negative bacillus in our hospi-tal during 2011-2016 were analyzed retrospectively. The consumption,target cure rate and treatment course of carbapenem antibiot-ics were analyzed statistically. The correlation between detection rate of drug-resistant bacteria with the consumption of carbapenem antibiotics was investigated by Pearson test. RESULTS:During 2011-2016,1222 strains of carbapenems-resistant Acinetobacter bauman (CRAB),655 strains of carbapenems-resistant Pseudomonas aeruginosa (CRPA) and 53 strains of carbapenem-resistant Escherichia coli (CRE) were detected in our hospital. The detection rates increased from 23.88%,8.92%,0.09% in 2011 to 80.34%,35.74%,0.97% in 2016. The types of carbapenem antibiotics in our hospital were mainly imipenem and meropenem. The consumption of them increased from 4222,145 g in 2011 to 7218,4387 g in 2016. The both target cure rates were all lower than 60%,and the proportion of the patients with treatment course >14 d was more than 65%. The detection rates of CRAB,CR-PA and CRE were positively correlated with the consumption of carbapenem antibiotics (r>0.9,P<0.05). CONCLUSIONS:The detection rate of carbapenems-resistant Gram-negative bacillus and drug consumption increase year by year in our hospital,and they have certain correlation. The target cure rate of carbapenem antibiotics in our hospital is in low level,and there is a long treatment course. They are should be standardized in the clinic. The selection of carbapenem antibiotics should be strictly followed clinical in-dications so as to reduce the generation of drug-resistant strains.

Isolation of Carbapenems-resistant Gram-negative Bacillus and Analysis of Producing Metallo-β-lactamase / 中国药房

OBJECTIVE:To provide reference for rational use of antibiotics in the clinic of our hospital. METHODS:Drug re-sistance of Gram-negative bacillus in the inpatients of our hospital were analyzed retrospectively during May 2013-Dec. 2015 as well as the situation of producing metallo-β-lactamase(MBLs). RESTUTS:A total of 2089 strains of Gram-negative bacillus were detected in our hospital during 2013-2015,among which there were 1456 strains of enterobacteria (69.70%) and 633 strains of non-fermentative bacteria,mainly involving Escherichia coli,Pseudomonas aeruginosa,Klebsiella pneumoniae,Acinetobacter bau-mannii and Enterobacter cloacae. A total of 406 strains of carbapenems-resistant bacteria were detected (19.44%),including 367 strains of non-fermentative bacteria and 39 strains of enterobacteria. The resistant rates of carbapenems-resistant strains to 16 antibi-otics were all higher than 50%,but those of non-carbapenems-resistant strains were in relative low level. Except for aztreonam,re-sistant rates of carbapenems-resistant strains to other 15 antbiotics were all higher than those of non-carbapenems-resistant strains, with statistical significance(P<0.05). A total of 36 strains of producing MBLs were detected(8.87%),including 13 strains of pro-ducing MBLs drug-resistant P. aeruginosa and 23 strains of producing MBLs drug-resistant A. baumannii;producing MBLs drug re-sistant enterobacteria had not been found. CONCLUSIONS:Gram-negative bacillus are mainly enterobacteria in our hospital;car-bapenems-resistant strains are mainly non-fermentative bacteria,resistant rate of them are commonly higher than that of non-drug-re-sistant strain. The situation of producing MBLs is serious,and enzyme producing strains are mainly non-fermentative bacteria. It is necessary to strengthen drug resistance of pathogen and enzyme producing strain monitoring,avoid the generation and spreading of drug-resistant strains due to irrational use of antibiotics.

Distribution and antimicrobial resistance of gram-negative bacilli isolated from wound specimens of orthopedic patients / 中国感染控制杂志

Objective To investigate the distribution and antimicrobial resistance of gram-negative bacilli isolated from wound specimens of orthopedic patients,and provide reference for the rational use of antimicrobial agents. Methods 682 isolates of gram-negative bacilli were collected from orthopedic department in a comprehensive hospi-tal between January 2011 and December 2013, antimicrobial susceptibility testing results were analyzed. Results The main gram-negative bacilli isolated from wound specimens of orthopedic patients were Pseudomonas aeruginosa (P .aeruginosa)(16.72%),Escherichia coli (E.coli)(15.40%),and Enterobacter cloacae (E.cloa-cae)(12.76%).The detection rates of extended-spectrum beta-lactamase-producing E.coli and Klebsialla pneu-moniae (K .pneumoniae)were 54.29%(57/105)and 31 .43% (22/70)respectively,and mainly distributed in the trauma orthopedic department,accounting for 49.12% and 45.45% respectively.The susceptibility rates of E.coli, K .pneumoniae ,and E.cloacae to meropenem and imipenem were all 100.00%.The susceptibility rates of E.coli and K .pneumoniae to amikacin,piperacillin-tazobactam and amoxicillin/clavulanic acid were all >80%.Suscepti-bility rate of E.cloacae to most antimicrobial agents were 71 .26% -100.00% except for piperacillin(64.37%). Susceptibility rates of P .aeruginosa to most antimicrobial agents were >85% except for cefepime (78.95%)and aztreonam (65.79%).Conclusion Gram-negative bacilli are the most common pathogens in wound infection of or-thopedics patients.In order to use antimicrobial agents rationally and improve clinical treatment effect,it is impor-tant to realize the distribution of pathogens and antimicrobial resistance.

Surveillance of antibiotic resistance in gram-negative bacilli strains collected from Chuzhou First Hospital during 2013 / 中国感染与化疗杂志

Objective To investigate the distribution and antibiotic resistance of gram-negative bacilli for better antimicrobial therapy in our hospital.Methods A retrospective analysis was conducted for the 1 060 strains of gram-negative bacilli isolated from clinical specimens during 2013.Results Of the 1 060 gram-negative bacterial strains isolated during 2013,E.coli,K . pneumoniae,P .aeruginosa and A.baumannii were the leading pathogens,accounting for 29.3%,22.8%,11.5% and 9.9%,respectively.The prevalence of extended spectrum-lactamases (ESBLs)positive strains was 63.7%,32.2% and 28.0% in E.coli,K .pneumoniae and P .mirabilis,respectively.The Enterobacteriaceae strains were highly sensitive to carbapenems.The percentage of the P .aeruginosa isolates resistant to meropenem,imipenem or amikacin was lower than 30%.The percentage of the Acinetobacter spp.(A.baumannii accounted for 70.9%)strains resistant to meropenem and imipenem were 25.0% and 26.2%.Conclusions Most of the gram-negative bacilli are resistant to multiple antimicrobial agents. We should strengthen the monitoring of the antibiotic resistance of gram-negative bacilli and optimize antimicrobial therapy.

Leclercia adecarboxylata isolation: case reports and review.

Leclercia adecarboxylata is usually isolated as a part of polymicrobial cultures in immunocompetent patients, and as a pure culture in immunocompromised persons. Although generally sensitive to most antibiotics, there are reports of resistant strains. Two case reports of L. adecarboxylata isolation in the lab in pure culture in immunocompetent persons are presented here, L. adecarboxylata being isolated from a vaginal swab in the first case and from a gluteal abscess in the second case. Both the isolates were sensitive to most of the antibiotics tested.

'Bobo-Newton syndrome': An unwanted gift from man's best friend.

Capnocytophaga canimorsus is a facultative Gram-negative bacillus that is typically a constituent of the oral flora of dogs and cats. It was first isolated by Bobo and Newton in 1976 from a man presenting with meningitis following a dog bite. Transmission to humans follows various animal-related injuries, which may be gross or subtle. C canimorsus can cause a spectrum of syndromes ranging from skin and soft tissue infection to invasive disease such as meningitis or endocarditis. The present article reports a case of C canimorsus meningitis in a patient with the classic risk factor of alcoholic liver cirrhosis. Clinical suspicion was confirmed by culture and genetic identification of the blood isolate. The present article reviews the Capnocytophaga genus, the clinical syndromes most commonly associated with this zoonotic organism, its laboratory identification and treatment.

Le Capnocytophaga canimorsus est un bacille Gram négatif facultatif qui fait généralement partie de la flore buccale des chiens et des chats. C'est Bobo et Newton qui l'ont isolé pour la première fois en 1976, chez un homme souffrant d'une méningite après avoir été mordu par un chien. La transmission aux humains est secondaire à plusieurs blessures liées aux animaux, qui peuvent être évidentes ou discrètes. Le C canimorsus peut causer une série de syndromes, de l'infection de la peau et des tissus mous à une maladie invasive comme la méningite ou l'endocardite. Le présent article rend compte d'un cas de méningite à C canimorsus chez un patient ayant les facteurs de risque classiques de cirrhose hépatique alcoolique. La présomption clinique a été confirmée par culture et identification génétique de l'isolat sanguin. Dans le présent article, on trouve une analyse du gène Capnocytophaga, des syndromes cliniques les plus associés à cet organisme zoonotique, de son identification en laboratoire et de son traitement.

The relation between pH value of gastric juice and ventilator-associated pneumonia in newborn / 中国小儿急救医学

Objective To investigate the pathogen and incidence of ventilator-associated pneumonia (VAP) under different pH value of gastric juice,and to explore the endogenous pathogenesis of VAP.Methods Ninety-eight cases were admitted in our neonatal intensive care unit from Dec 2008 to Dec 2010.According to whether VAP happened,they were divided into VAP group (52 cases) and non-VAP group (46 cases).The relation between pH value of gastric juice and the species of pathogenic bacteria in stomach was analyzed.Results The incidence of VAP was 53.1％ (52/98).The pH value of gastric juice affected the species of pathogenic bacteria in stomach.When pH ≤ 4,the major species of pathogenic bacteria were Candida and Gram-positive bacillus; and pH ＞ 4,the major species were Gram-negative bacillus.The incidence of VAP was 34.5％ (10/29) when pH≤4;on the contrary,the incidence was 60.9％ (42/69) when pH ＞ 4.The incidence of VAP at the time of pH ＞ 4 was significantly higher than that of pH ≤4 ( x2 =5.71,P =0.017).Conclusion The pH value of gastric juice is an important factor of the species of pathogenic bacteria in stomach,especially for Gram-negative bacillus,including multi-drug resistant extended-spectrum β-lactamase-producing bacteria.The higher of pH value,the incidence of VAP is higher.