Resistance Rate Of Gram-negative Bacteria Research Articles

Gram-Negative Bloodstream Infections in a Medical Intensive Care Unit: Epidemiology, Antibiotic Susceptibilities, and Risk Factors for in-Hospital Death.

Gram-negative bloodstream infection (GNBI) poses a serious threat to critically ill patients. This retrospective study aimed to uncover drug resistance of pathogens and the GNBI effect on in-hospital death and distinguish death risk factors in a medical intensive care unit (ICU). A retrospective study of all GNBI patients in the medical ICU of the Third Xiangya Hospital over 9 nine years was conducted. Blood samples were performed by a BACTEC 9240 system, MALDI-TOF MS, Bruker and Vitek-2 system. Logistic regression was used for analyzing risk factors for death. Seventy-five episodes of GNBI developed in 68 (1.4%) out of 4954 patients over a span of 9 years. The most frequently isolated bacterium was Klebsiella pneumoniae, with the lungs as the predominant source of GNBI. The resistance rate of Gram-negative bacteria to polymyxin B was 11.6% after excluding those intrinsically resistant non-fermentativebacteria. All Enterobacter spp. were susceptible to ceftazidime/avibactam. Thirty-three (48.5%) patients underwent inappropriate empirical antibiotic treatment and 48 (70.6%) patients died during the hospitalization. Multivariate logistic regression analysis identified that lymphocyte count at GNBI onset ≤0.5×109/L, invasive mechanical ventilation, and septic shock were related to in-hospital death. Body mass index ≥23 and appropriate empirical antibiotic use after GNBI were negatively associated with in-hospital death. GNBI was a frequent complication among patients in the medical ICU. This study underscored the presence of diverse factors that either heightened or attenuated the risk of in-hospital death.

Severe and complicated soft tissue infections: a single-centre case series.

To assess the demographic and clinical characteristics, laboratory findings, and economic burden of patients with a diagnosis of complicated skin and soft tissue infection (cSSTI). The demographic and clinical characteristics, laboratory findings, surgical interventions, cost of treatment, and outcome of patients diagnosed with cSSTIs between January 2017 and December 2019 were retrospectively analysed. A total of 24 patients with cSSTIs were included in the study. The median age was 53 (22-85) years, and 14 (58%) were female. The most common comorbidity was diabetes (54%). On admission, 75% of patients presented with sepsis, and 70% had a high-grade Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) score. The causative microorganism was isolated from 21 (87%) patients, and the multidrug resistance rate of Gram-negative bacteria was 50%. The median number of debridements was 3 (1-12). In all, 11 patients were followed up in the intensive care unit, and the mortality rate was 29%. The presence of confusion (p=0.025), causative Gram-negative microorganisms (p=0.009), hyponatraemia (p=0.034), the need for intensive care (p=0.001), anti-meticillin-resistant Staphylococcus aureus antibiotics (p=0.023) and the rate of antibiotic changes during treatment (p=0.019) were significantly higher in the non-survival patient group. Hyponatraemia was a significant independent risk factor for mortality (p=0.048). The median cost of per-patient treatment was $9453 USD in the non-surviving and $1536 in the surviving group. It is important to know possible factors and local resistance rates at the beginning of empirical antibacterial and surgical treatment. The presence of hyponatraemia, sepsis and a high LRINEC score can be considered to be the mortality predictors.

Surveillance of antimicrobial resistance in human health in Tanzania: 2016-2021.

Antimicrobial resistance (AMR) surveillance plays an important role in early detection of resistant strains of pathogens and informs treatments decisions at local, regional and national levels. In 2017, Tanzania developed a One Health AMR Surveillance Framework to guide establishment of AMR surveillance systems in the human and animal sectors. We reviewed AMR surveillance studies in Tanzania to document progress towards establishing an AMR surveillance system and determine effective strengthening strategies. We conducted a literature review on AMR studies conducted in Tanzania by searching Google Scholar, PubMed, and the websites of the Tanzania Ministry of Health and the World Health Organization for articles written in English and published from January 2012 to March 2021 using relevant search terms. Additionally, we reviewed applicable guidelines, plans, and reports from the Tanzanian Ministry of Health. We reviewed 10 articles on AMR in Tanzania, where studies were conducted at hospitals in seven of Tanzania's 26 regions between 2012 and 2019. Nine AMR sentinel sites had been established, and there was suitable and clear coordination under 'One Health'. However, sharing of surveillance data between sectors had yet to be strengthened. Most studies documented high resistance rates of Gram-negative bacteria to third-generation cephalosporins. There were few laboratory staff who were well trained on AMR. Important progress has been made in establishing a useful, reliable AMR surveillance system. Challenges include a need to develop, implement and build investment case studies for the sustainability of AMR surveillance in Tanzania and ensure proper use of third-generation cephalosporins. This article adds to the knowledge base of AMR trends in Tanzania and progress made in the implementation of AMR surveillance in human health sector as a contribution to the global AMR initiatives to reduce AMR burden worldwide. It has highlighted key gaps that need policy and implementation level attention.

1787. County Level Association Between the Rate of Fluoroquinolone-Resistance Gram Negative Bacteria and Fluoroquinolone Utilization in Kansas

Abstract Background Kansas ranks as the 8th-worst state nationally for outpatient antibiotic prescribing, with a rate of 690 antibiotic prescriptions per 1000 population. The statewide rate of fluoroquinolone (FQ) is disproportionately higher than other antibiotic drug classes. Statewide antibiograms can be developed by health departments for antimicrobial stewardship monitoring. The purpose of this study was to investigate the correlation between the FQ resistance rate of gram-negative bacteria to FQ consumption. Methods A retrospective design utilizing 2018-2019 county level FQ-resistant Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa was categorized by county level based on the Kansas statewide antibiogram. Outpatient FQ utilization data was obtained from IQVIA and categorized into county level FQ rate based on prescriptions dispensed per 1000 population. Linear regression was used to compare antibiotic resistance (AR) to FQ utilization by county. Results Sixty-six of 123 facilities contacted for antibiogram data responded with results. Of these, 47 were critical access hospitals, and the rest were acute care hospitals or clinics. A total of 31,573 E. coli isolates, 5,942 K. pneumoniae and 5,017 P. aeruginosa isolates were represented. All 106 counties had FQ prescription data. Of the 49 counties with AR reported, FQ rates ranged from 4.6 to 105.6/1000 population. There was no statistical significance associated between counties for FQ-resistant E. coli, K. pneumoniae or P. aeruginosa with FQ-utilization rates (p=0.184, 0.572, 0.352, respectively). Comparing urban and rural regions was also compared for each AR-FQ use combination. There was statistical significance for urban P. aeruginosa FQ-resistance and FQ utilization (p=0.025), but not for urban E. coli (p=0.120) or urban K. pneumoniae (p=0.331). Conclusion A strong correlation was demonstrated between FQ consumption and rates of FQ-resistant P. aeruginosa within urban counties. No significant correlations were found between FQ consumption rates and other organisms. This study demonstrates additional applications for state-level antibiogram data, particularly when paired with antibiotic use data. Disclosures All Authors: No reported disclosures.

Temperature-Enhanced mcr-1 Colistin Resistance Gene Detection with Electrochemical Impedance Spectroscopy Biosensors.

Antibiotic resistance is now one of the biggest threats humankind is facing, as highlighted in a declaration by the General Assembly of the United Nations in 2016. In particular, the growing resistance rates of Gram-negative bacteria cause increasing concerns. The occurrence of the easily transferable, plasmid-encoded mcr-1 colistin resistance gene further worsened the situation, significantly enhancing the risk of the occurrence of pan-resistant bacteria. There is therefore a strong demand for new rapid molecular diagnostic tests for the detection of mcr-1 gene-associated colistin resistance. Electrochemical impedance spectroscopy (EIS) is a well-suited method for rapid antimicrobial resistance detection as it enables rapid, label-free target detection in a cost-efficient manner. Here, we describe the development of an EIS-based mcr-1 gene detection test, including the design of mcr-1-specific peptide nucleic acid probes and assay specificity optimization through temperature-controlled real-time kinetic EIS measurements. A new flow cell measurement setup enabled for the first time detailed real-time, kinetic temperature-controlled hybridization and dehybridization studies of EIS-based nucleic acid biosensors. The temperature-controlled EIS setup allowed single-nucleotide polymorphism discrimination. Target hybridization at 60 °C enhanced the perfect match/mismatch (PM/MM) discrimination ratio from 2.1 at room temperature to 3.4. A hybridization and washing temperature of 55 °C further increased the PM/MM discrimination ratio to 5.7 by diminishing the mismatch signal during the washing step while keeping the perfect match signal. This newly developed mcr-1 gene detection test enabled the direct, specific label, and amplification-free detection of mcr-1 gene harboring plasmids from Escherichia coli.

Local microbiological monitoring as a basis for determining etiological significance of conditional pathogens: data from a burn intensive care unit

Objective. To assess the etiology of infections, microbial associations and antimicrobial resistance in a burn intensive care unit. Materials and Methods. A microbiological study of 1322 biological samples from 195 patients with extensive burns included 479 blood samples, 82 respiratory samples, 326 urine samples, and 435 wound samples. Antimicrobial susceptibility testing was performed, and coefficients of constancy and associativity (CA), as well as the Jaccard coefficient were calculated. Results. The etiology of infections was represented by: Pseudomonas aeruginosa – 23%, Acinetobacter baumannii – 19.1%, Enterococcus faecalis – 18.6%, Klebsiella pneumoniae – 8.2%, CoNS (coagulasenegative staphylococci) – 8.2%, Staphylococcus aureus – 7.1%, Candida albicans – 7.1%, Candida non-albicans – 3%, other species were isolated with a frequency of less than 2%. Majority of the above mentioned pathogens showed high associativity: non-fermenting rods (NFR), S. aureus, Enterobacterales, E. faecalis, Candida non-albicans formed associations in 60.0%, 88.8%, 83.0%, 83.3% and 65% of cases, respectively. The prevalence of methicillin-resistant strains of S. aureus and CoNS was 71% and 81%, respectively. CoNS showed higher resistance to fluoroquinolones and gentamicin compare to S. aureus: 42% vs 23%, 46% vs 29%, respectively (χ2 = 6.91; p = 0.086; χ2 = 6.58; p = 0.013). E. faecalis showed high resistance rates to aminoglycosides and fluoroquinolones (> 60%). All Gram-positive isolates were completely susceptible to vancomycin, linezolid, tigecycline, and teicoplanin. Resistance rates of Gram-negative bacteria (NFR, K. pneumoniae) to penicillins, cephalosporins, carbapenems (for NFR), and aminoglycosides were high (from 60% to 100%). The most active antimicrobial against NFR was colistin. Resistance of K. pneumoniae isolates to carbapenems was 23%, while other enterobacteria were highly susceptible to carbapenems. Conclusions. The implementation of the local microbiological monitoring made it possible to characterize the qualitative pathogen structure and antimicrobial resistance in our burns intensive care unit. This data will serve as the basis for improving of the infection control and antimicrobial stewardship.

Carbapenem resistance rates in Gram-negative bacteria in nosocomial infections: A retrospective study from a tertiary hospital

Aim: Just like the rest of the world, the frequency of nosocomial infections is increasing in our country. The aim of this study is to evaluate the change in carbapenem resistance rates of Gram-negative bacteria isolated from health care related infections over the years.Materials and Methods: The study was performed retrospectively between January 2014 and December 2017. Obtained from clinics with hospital surveillance; according to criteria for the diagnosis of nosocomial infections set by the Centers for Disease Control and Prevention (CDC); Gram-negative factors were examined in patients. Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli strains were evaluated.Results: Carbapenem resistance of A. baumannii strains was 90.7% in 2014 and was 95.9% in 2017. Among the E. coli strains, the rate of carbapenem resistance of 4.1% in 2014, was 7.5% in 2017. While the resistance rate among K. pneumoniae strains was 32.2% in 2014, this rate increased to 48.9% in 2017. Among the P. aeruginosa species, the carbapenem resistance rate was 26.3% in 2014, increased to 38.4% in 2017.Conclusion: In the study, we determined that carbapenem resistance was very high in Acinetobacter spp strains while the resistance rate for Klebsiella spp strains has increased dramatically over the years. Knowing the data will be a guide for the clinicians in selecting empirical antibiotic agents, especially in critical intensive care unit patients, and will guide the development of infection control programs and antibiotic control programs in order to reduce the rate of resistance.

High antimicrobial resistant rates among Gram-negative pathogens in intensive care units. A retrospective study at a tertiary care hospital in Southwest Saudi Arabia.

Objectives:To determine the distribution and resistance profiles of Gram-negative bacteria (GNB) in intensive care units (ICUs) at King Abdullah Hospital in Bisha, Saudi Arabia.Methods:A record based retrospective study was conducted from December 2016 to January 2018. In total, 3736 non-duplicate clinical specimens from the general intensive care unit (ICU), neonatal ICU (NICU), and coronary CU (CCU) were analyzed for pathogens.Results:Of 3736 specimens, 9.6% (358) were positive for pathogens, and GNB constituted the majority (290/358; 81%). Acinetobacter is predominant in the general ICU, whereas Klebsiella pneumoniae is common in the NICU and CCU. Overall, GNB revealed a high resistance rate for cefuroxime (75.8%) trimethoprim/sulfamethoxazole (73.4%), cefotaxime (72.9%), aztreonam (64.6%), piperacillin (62.1%), and ciprofloxacin (61.5%). Acinetobacter revealed a high resistance (93.4% to 97.5%) to all antimicrobials except colistin (4%). Klebsiella pneumoniae showed a high resistance to trimethoprim/sulfamethoxazole (71.8%), cefotaxime (71.4%) and aztreonam (65.2%). Pseudomonas aeruginosa showed good activity for aminoglycosides but increasing resistance for cephalosporins and meropenem. GNB exhibited a high rate of multi-drug-resistant (MDR) phenotypes (67.9%) with a higher level among Acinetobacter spp. (97.5%). There were no significant differences in the resistance rates of GNB from different ICUs except for imipenem (p=0.002) and ciprofloxacin (p=0.003).Conclusions:Increased antimicrobial resistance with high proportions of MDR patterns were found among GNB from ICUs. Comprehensive surveillance programs are needed to track the origins and emergence pathways of resistant pathogens.

Traditional empiric antibiotic treatment is still effective for neonatal fever.

Fever may be the only sign of a serious bacterial infection (SBI) in neonates. Ampicillin plus cefotaxime (A+C) and ampicillin plus gentamicin (A+G) are commonly used as empiric therapies for Escherichia coli, Group B Streptococcus (GBS) and Listeria monocytogenes, which are the most likely neonatal SBI pathogens (1). Culture-based screening and prophylaxis has significantly lowered GBS infections and an alarming increase in the antimicrobial resistance rates of Gram-negative bacteria, including cefotaxime and gentamicin resistance, has been reported (1-3). We examined whether the current empiric treatment for neonatal SBI, namely A+G and A+C was still appropriate and identified easily recognisable risk factors for antimicrobial resistance. This article is protected by copyright. All rights reserved.

Clinical Characteristics of Nosocomial Bloodstream Infections in Neonates in Two Hospitals, China.

The improvement of medical condition requires prolonged hospital stays, which increase the risk of nosocomial bloodstream infections (BSIs). All nosocomial BSI newborns in two hospitals were included, and the demographic and clinical characteristics of bacteremia patients were obtained from the information systems. Isolates were identified by biochemical assays. Antimicrobial susceptibility was determined using disk diffusion method. Except for three same risk factors, intubation with mechanical ventilation was a risk factor in Chongqing, while low birth weight was a risk factor in Henan. Klebsiella pneumoniae was the predominant strain in Chongqing, and Escherichia coli was the most prevalent strain in Henan. The resistance rate of gram-negative bacteria in Henan was higher than that of strains in Chongqing. The risk factors and resistance rate of pathogens were different in different areas. Therefore, treatment protocols should be established based on the trends of drug resistance and bacterial spectrum.

Antimicrobial resistance pattern: a report of microbiological cultures at a tertiary hospital in Tanzania.

BackgroundAntimicrobial resistance has been declared by the World Health Organization as a threat to the public health. The aim of this study was to analyze antimicrobial resistance patterns of the common pathogens occurring at the Bugando Medical Centre (BMC), Mwanza, Tanzania to provide data for antimicrobial stewardship programmes.MethodsA total of 3330 microbiological culture results scripts representing non-repetitive specimens reported between June 2013 and May 2015 were retrieved and analyzed for pathogens and their susceptibility patterns using STATA-11 software.ResultsOut of 3330 specimens, 439 (13.2%) had positive culture. Staphylococcus aureus (n = 100; 22.8%), Klebsiella pneumoniae (n = 65; 14.8%) and Escherichia coli (n = 41; 9.3%) were the most frequently isolated bacteria. Of 78 Staphylococcus aureus tested, 27 (34.6%) were found to be methicillin resistant Staphylococcus aureus (MRSA). Rates of resistance of Klebsiella pneumoniae and Escherichia coli isolates to third generation cephalosporins were 38.5% (25/65) and 29.3% (12/41) respectively. Staphylococcus aureus and Klesbiella pneumoniae were commonly isolated from bloodstream infections while Escherichia coli and Pseudomonas aeruginosa were the predominant isolates from urinary tract and wounds infections respectively. Of 23 Salmonella species isolated, 22 (95%) were recovered from the blood. Nine of the 23 Salmonella species isolates (39%) were found to be resistant to third generation cephalosporins. The resistance rate of gram-negative bacteria to third generation cephalosporins increased from 26.5% in 2014 to 57.9% in 2015 (p = 0.004) while the rate of MRSA decreased from 41.2% in 2013 to 9.5% in 2015 (p = 0.016). Multidrug-resistant gram-negative isolates were commonly isolated from Intensive Care Units and it was noted that, the majority of invasive infections were due to gram-negative bacteria.ConclusionThere is an increase in proportion of gram-negative isolates resistant to third generation cephalosporins. The diversity of potential pathogens resistant to commonly prescribed antibiotics underscores the importance of sustained and standardized antimicrobial resistance surveillance and antibiotic stewardship programmes in developing countries.

Perioperative application of preventive antibiotics for patients with esophageal carcinoma

Objective To analyze the distribution and antibiotic resistance of pathogens isolated from sputum in early postoperative patients after esophageal surgery, and investigate the risk factors of pulmonary infections after esophageal carcinoma and reasonable application of antibiotics during perioperative period. Methods The clinical data of 414 patients with esophageal carcinoma who were admitted to the Affiliated Hospital of Binzhou Medical University from January 2012 to June 2014 were retrospectively analyzed. The second generation cephalosporins were used as preventive antibiotics for the 181 patients between January and December 2012 and the third generation cephalosporins were used for the 233 patients between January 2013 and June 2014. Sputum samples were collected and inspected before operation and in the first three days after operation for observing distribution and antibiotic resistance of pathogens. The incidence of postoperative pulmonary infection was observed in the two kinds of patients. The risk factors closely related to the occurrence of postoperative pulmonary infections were analyzed. Comparison of rate and univariate analysis were done by chi-square test. Multivariate analysis was done with logistic regression. Results The positive rate of early post-operative sputum culture was 24.64%(102/414), 32.04%(58/181) in patients receiving the second generation cephalosporins and 18.88%(44/233) in patients receiving the third generation cephalosporins, respectively, with a significant difference between the two generations of cephalosporins (χ2=9.502, P<0.05). A total of 131 strains of pathogens were isolated from early postoperative sputum samples including 12 strains of gram-positive bacteria and 119 strains of gram-negative bacteria. The top three bacteria were Klebsiella pneumoniae subsp pneumoniae (33 trains), Acinetobacter baumannii (20 strains) and Pseudomonas aeruginosa (19 strains). The resistance rate of gram-negative bacteria in early postoperative sputum samples to meropenem, ciprofloxacin and levofloxacin were 5.0%-25.0%, 2.6%-15.2%, 2.6%-20.0%, respectively. Among cephalosporins, the resistance rate to ceftriaxone, cefotaxime, cefepime, ceftazidime, cefuroxime and cefazolin were 10.3%-20.0%, 5.3%-30.0%, 12.8%-31.6%, 15.4%-42.1%, 21.2%-55.0% and 15.2%-60.0%, respectively. The overall postoperative pulmonary infection rate was 18.60%(77/414). The pulmonary infection rate of patients receiving the second generation cephalosporins was 26.52%(48/181), which was higher than 12.45%(29/233) of patients receiving the third generation cephalosporins (χ2=13.326, P<0.05). The results of univariate analysis showed that smoking, chronic obstructive pulmonary disease, application of the second generation cephalosporins during the perioperative period and early postoperative sputum culture positive were correlated with the postoperative pulmonary infection after esophageal carcinoma surgery (χ2=5.149, 22.765, 13.326, 159.092, P<0.05). Multivariate statistical analysis with logistic regression demonstrated that application of the third generation cephalosporins during the perioperative period was independent protective factor of postoperative pulmonary infection (OR=2.582, 95% confidence interval: 1.331-5.009, P<0.05). Conclusions The pathogens from sputum in early postoperative period after esophageal surgery are complicated with gram-negative bacteria as the main pathogens especially Klebsiella pneumoniae subsp, pneumoniae, and different levels of antibiotic resistance are ubiquitous. The third generation cephalosporins can effectively prevent the postoperative pulmonary infection after esophageal carcinoma surgery. Key words: Esophageal neoplasms; Perioperative period; Pulmonary infection; Pathogen; Preventive antibiotics

Increasing resistance rate to carbapenem among blood culture isolates of Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa in a university-affiliated hospital in China, 2004-2011.

The objective of this study is to investigate the profile of antimicrobial resistance of Gram-negative bacteria in blood cultures from 2004-2011. Pathogens from positive blood cultures were subcultured, and identified in the First Affiliated Hospital of Nanjing Medical University from January 2004 to December 2011. The antibiotic resistance pattern was analyzed by WHONET 5.4. A total of 1224 cases of Gram-negative bacterial isolates were documented, accounting for 38.6% of the total pathogens isolated from positive blood cultures in the 8-year period. The isolation rates of Klebsiella pneumoniae and Acinetobacter baumannii increased nearly three times over the same time span. Most Gram-negative bacteria isolates, except the isolates of Pseudomonas aeruginosa, showed a significantly increased resistance rate to cephalosporins (in particular third/fourth generation cephalosporins). Noteworthy, the antimicrobial resistance of K. pneumoniae, A. baumannii and P. aeruginosa isolates to carbapenem (imipenem and meropenem) was significantly increased and the resistant rate to carbapenem was >80.0% in A. baumannii in 2011. The results from PCR detection for carbapenemases were as follows: 82.8% (24/29) isolates of K. pneumoniae carried the kpc-2 gene; only three metallo-beta-lactamase-positive P. aeruginosa isolates were detected; and 93.1% (67/72) A. baumannii isolates were blaOXA-23 positive. The antimicrobial resistance rate of Gram-negative bacteria isolated from blood cultures significantly increased from 2004 to 2011, with significant resistance to the third/fourth generation cephalosporins and carbapenem.

Etiological Agents in Bacteremia of Children with Hemato-oncologic Diseases (2006-2010): A Single Center Study

Purpose : This study was performed to identify the etiologic agents and antimicrobial susceptibility patterns of organisms responsible for bloodstream infections in pediatric cancer patients for guidance in empiric antimicrobial therapy. Methods : A 5-year retrospective study of pediatric hemato-oncologic patients with bacteremia in Seoul National University Children's Hospital, from 2006 to 2010 was conducted. Results : A total of 246 pathogens were isolated, of which 63.4% (n=156) were gram-negative, bacteria 34.6% (n=85) were gram-positive bacteria, and 2.0% (n=5) were fungi. The most common pathogens were Klebsiella spp. (n=61, 24.8%) followed by Escherichia coli (n=31, 12.6%), coagulase-negative staphylococci (n=23, 9.3%), and Staphylococcus aureus (n=22, 8.9 %). Resistance rates of gram-positive bacteria to penicillin, oxacillin, and vancomycin were 85.7%, 65.9%, and 9.5%, respectively. Resistance rates of gram-negative bacteria to cefotaxime, piperacillin/tazobactam, imipenem, gentamicin, and amikacin were 37.2%, 17.1%, 6.2%, 32.2%, and 13.7%, respectively. Overall fatality rate was 12.7%. Gram-negative bacteremia was more often associated with shock (48.4% vs. 11.9%, P

Analysis of distribution and antibiotic resistance of pathogens in lower respiratory infection

Objective To investigate the distribution and antibiotic resistance of pathogens in the patients with lower respiratory infections in our hospital. Methods Bacterial culture was preformed from sputum specimens of diagnosed patients with lower respiratory infections in our hospital. Bacterium's appraisal and antimi-crobial susceptibility test for positive specimens were preformed by the Microscan A/S-4 semi-automatic bacteria of America's spirit company and drug susceptibility analyzer and its supporting identification and drug susceptibility plate. Results Gram-negative bacilli were the major microorganism in bacterium. The top 5 pathogens are Pseudomo-nas aeruginosa, pneumonia crayresearch bacteria, baumanii/haemolyticus, Xanthomonas maltophilia and Escheri-chia coli. Drug sensitive experiments showed the resistance rate of gram-negative bacteria to broad-spectrum antibi-otics was increased. Drug resistance rate of pseudomonas aeruginosa against Ceftriaxine, pneumonia crayresearch bacteria and colon bacillus against penicillins and cephalosporin and Ammonia Qu Na was above 60%, 80% and 50% respectively. The resistant rate of Baoman/hematolysis bacillus to the majority antibiotics is above 70%, which of Xanthomonas maltophilia to cephalosporins, quinolones and aminoglycosides were above 90%. Coagulase-negative staphylococcus as the core of Gram-positive bacteria, the resistant rate to Penicillin and cephalosporin are above 85%. The resistance rate of staphylococcus to the majority antibiotics was comparatively low. Conclusions More attention should be paid on distribution and diversify of bacterium in lower respiratory infections clinically and rational use of antibiotics. Key words: Respiratory infection; Pathogenic bacteria; Antibacterial