Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogenic bacterium with complex pathogenesis and drug resistance mechanisms. It has high morbidity and mortality and can cause acute and chronic infections in immunocompromised individuals, with lung infections, wound infections, and bloodstream infections being the most common. The animal infection model of P. aeruginosa is of great value for in-depth research on the pathogenicity, drug resistance, and therapeutic measures of P. aeruginosa by simulating the pathways of human bacterial infections. This article firstly summarizes the selection, anesthesia, and disposal of experimental animals in the construction of animal models of P. aeruginosa infection, and then reviews the methods of construction, model evaluation, and applications of animal models of P. aeruginosa pulmonary infection, wound infection, and bloodstream infection, in order to provide a reference for scientific research related to P. aeruginosa infectious diseases.
Humans ; Animals ; Pseudomonas Infections/microbiology* ; Models, Animal ; Virulence ; Pseudomonas aeruginosa ; Disease Models, Animal

Objective: To identify the antibiotic resistance, virulence genes, and sequence types of Pseudomonas aeruginosa (P. aeruginosa) strains isolated from blood. Methods: From November 2014 to December 2021, a total of 94 nonrepetitive P. aeruginosa isolates were obtained from blood samples of patients at the First Affiliated Hospital of Shandong First Medical University in Shandong Province, China. The bacteria were identified using matrix-assisted laser desorption ionization time of flight mass spectrometry. Antibiotic resistance of the P. aeruginosa isolates was detected using Vitek 2 Compact system. Polymerase chain reaction (PCR) was conducted for the 18 virulence genes, and multi locus sequence typing (MLST) was performed to identify the sequence types of the P. aeruginosa strains. The resistance rates and distributions of virulence genes between carbapenem resistant pseudomonas aeruginosa (CRPA) and carbapenem susceptible pseudomonas aeruginosa (CSPA) isolates were compared using the Chi-square test. Results: Among 94 P. aeruginosa isolates, 19 (20.2%) isolates were found to be multidrug resistant (MDR) bacteria, of which 17 were CRPA isolates and 2 were CSPA isolates. All strains contained more than 10 virulence genes. Except for exoU gene, the detection rate of other genes was above 83%. MLST analysis revealed a total of 66 different STs, including 59 existing STs and 7 novel STs. Among them, ST244 (n=11, 11.7%) and ST270 (n=7, 7.4%) were the dominant STs. Although these two types of isolates harbored the same virulence genes, the resistance rates to carbapenem were different. 54.5% (6/11) ST244 isolates were CRPA but all 7 ST270 isolates were CSPA. Conclusion: Although the resistance rates of P. aeruginosa strains isolated from blood were at a low level, some MDR and CRPA isolates were detected. As the high virulence gene detection rates and genetic diversity were found for P. aeruginosa strains isolated from blood, close attention should be paid to avoid transmission and outbreaks.
Humans ; Pseudomonas aeruginosa/genetics* ; Multilocus Sequence Typing ; Molecular Epidemiology ; Pseudomonas Infections/microbiology* ; Microbial Sensitivity Tests ; Hospitals ; Carbapenems/pharmacology* ; Drug Resistance, Multiple, Bacterial/genetics* ; Anti-Bacterial Agents/pharmacology* ; beta-Lactamases

Objective: To identify the antibiotic resistance, virulence genes, and sequence types of Pseudomonas aeruginosa (P. aeruginosa) strains isolated from blood. Methods: From November 2014 to December 2021, a total of 94 nonrepetitive P. aeruginosa isolates were obtained from blood samples of patients at the First Affiliated Hospital of Shandong First Medical University in Shandong Province, China. The bacteria were identified using matrix-assisted laser desorption ionization time of flight mass spectrometry. Antibiotic resistance of the P. aeruginosa isolates was detected using Vitek 2 Compact system. Polymerase chain reaction (PCR) was conducted for the 18 virulence genes, and multi locus sequence typing (MLST) was performed to identify the sequence types of the P. aeruginosa strains. The resistance rates and distributions of virulence genes between carbapenem resistant pseudomonas aeruginosa (CRPA) and carbapenem susceptible pseudomonas aeruginosa (CSPA) isolates were compared using the Chi-square test. Results: Among 94 P. aeruginosa isolates, 19 (20.2%) isolates were found to be multidrug resistant (MDR) bacteria, of which 17 were CRPA isolates and 2 were CSPA isolates. All strains contained more than 10 virulence genes. Except for exoU gene, the detection rate of other genes was above 83%. MLST analysis revealed a total of 66 different STs, including 59 existing STs and 7 novel STs. Among them, ST244 (n=11, 11.7%) and ST270 (n=7, 7.4%) were the dominant STs. Although these two types of isolates harbored the same virulence genes, the resistance rates to carbapenem were different. 54.5% (6/11) ST244 isolates were CRPA but all 7 ST270 isolates were CSPA. Conclusion: Although the resistance rates of P. aeruginosa strains isolated from blood were at a low level, some MDR and CRPA isolates were detected. As the high virulence gene detection rates and genetic diversity were found for P. aeruginosa strains isolated from blood, close attention should be paid to avoid transmission and outbreaks.
Humans ; Pseudomonas aeruginosa/genetics* ; Multilocus Sequence Typing ; Molecular Epidemiology ; Pseudomonas Infections/microbiology* ; Microbial Sensitivity Tests ; Hospitals ; Carbapenems/pharmacology* ; Drug Resistance, Multiple, Bacterial/genetics* ; Anti-Bacterial Agents/pharmacology* ; beta-Lactamases

Pseudomonas aeruginosa is the most common pathogen of burn wound infection. It can encode a variety of virulence factors and is highly pathogenic, which can lead to poor prognosis and high mortality. In order to research a new method to combat Pseudomonas aeruginosa infection, researchers have observed a wide range of interactions between the bacteriophages and the host. Bacteriophages influence and even dominate the structure, movement, and metabolism of host bacteria through a variety of mechanisms, catalyze the evolution of the host, and are also an important factor in host environmental adaptability and pathogenicity. In this paper, the interaction between Pseudomonas aeruginosa bacteriophages and the host is reviewed from the single cell level and the population level. Understanding these interactions could provide new idea for the treatment of Pseudomonas aeruginosa clinical infections, provides a basis for future development of antimicrobial agents and guides the treatment of burn infections.
Bacteriophages ; Burns/therapy* ; Humans ; Pseudomonas Infections/microbiology* ; Pseudomonas Phages ; Pseudomonas aeruginosa ; Virulence Factors

BACKGROUND: Ciprofloxacin is usually used in the treatment of lower respiratory tract infections (LRTIs). Recent studies abroad have shown ciprofloxacin is inadequately dosed and might lead to worse outcomes. The aim of this study was to perform pharmacokinetic and pharmacodynamic analyses of ciprofloxacin in elderly Chinese patients with severe LRTIs caused by Gram-negative bacteria. METHODS: From September 2012 to June 2014, as many as 33 patients were empirically administered beta-lactam and ciprofloxacin combination therapy. Patients were infused with 200 or 400 mg of ciprofloxacin every 12 h, which was determined empirically by the attending physician based on the severity of the LRTI and the patient's renal condition. Ciprofloxacin serum concentrations were determined by high-performance liquid chromatography. Bacterial culture was performed from sputum samples and/or endotracheal aspirates, and the minimum inhibitory concentrations (MICs) of ciprofloxacin were determined. The ratios of the area under the serum concentration-time curve to the MIC (AUC/MIC) and of the maximum serum concentration of the drug to the MIC (Cmax/MIC) were calculated. The baseline data and pharmacokinetic parameters were compared between clinical success group and clinical failure group, bacteriologic success group and bacteriologic failure group. RESULTS: Among the 33 patients enrolled in the study, 17 were infected with Pseudomonas aeruginosa, 14 were infected with Acinetobacter baumannii, and two were infected with Klebsiella pneumoniae. The mean age of the patients was 76.9 ± 6.7 years. Thirty-one patients (93.4%) did not reach the target AUC/MIC value of >125, and 29 patients (87.9%) did not reach the target Cmax/MIC value of >8. The AUC/MIC and Cmax/MIC ratios in the clinical success group were significantly higher than those in the clinical failure group (61.1 [31.7-214.9] vs. 10.4 [3.8-66.1], Z = -4.157; 9.6 [4.2-17.8] vs. 1.3 [0.4-4.7], Z = -4.018; both P < 0.001). The AUC/MIC and Cmax/MIC ratios in the patients for whom the pathogens were eradicated were significantly higher than those in the patients without the pathogens eradicated (75.3 [31.7-214.9] vs. 10.5 [3.8-66.1], Z = -3.938; 11.4 [4.2-17.8] vs. 1.4 [0.4-5.4], Z = -3.793; P < 0.001 for both). Receiver operating characteristic curve analysis showed that the AUC/MIC and Cmax/MIC values were closely associated with clinical and bacteriologic efficacies (P < 0.001 in both). CONCLUSIONS Ciprofloxacin is inadequately dosed against Gram-negative bacteria, especially for those with relatively high MIC values. Consequently, the target values, AUC/MIC > 125 and Cmax/MIC > 8, cannot be reached.
Acinetobacter baumannii ; drug effects ; pathogenicity ; Aged ; Aged, 80 and over ; Chromatography, High Pressure Liquid ; Ciprofloxacin ; pharmacokinetics ; pharmacology ; Female ; Gram-Negative Bacteria ; drug effects ; pathogenicity ; Humans ; Male ; Microbial Sensitivity Tests ; Pseudomonas aeruginosa ; drug effects ; pathogenicity ; Respiratory Tract Infections ; drug therapy ; metabolism ; microbiology

ObjectiveWorldwide, community-acquired pneumonia (CAP) is a common infection that occurs in older adults, who may have pulmonary comorbidities, including chronic obstructive pulmonary disease (COPD). Although there have been clinical studies on the coexistence of CAP with COPD, there remain some controversial findings. This review presents the current status of COPD in CAP patients, including the disease burden, clinical characteristics, risk factors, microbial etiology, and antibiotic treatment.

Data SourcesA literature review included full peer-reviewed publications up to January 2018 derived from the PubMed database, using the keywords "community-acquired pneumonia" and "chronic obstructive pulmonary disease".

Study SelectionPapers in English were reviewed, with no restriction on study design.

ResultsCOPD patients who are treated with inhaled corticosteroids are at an increased risk of CAP and have a worse prognosis, but data regarding the increased mortality remains unclear. Although Streptococcus pneumoniae is still regarded as the most common bacteria isolated from patients with CAP and COPD, Pseudomonas aeruginosa is also important, and physicians should pay close attention to the occurrence of antimicrobial resistance, particularly in these two organisms.

ConclusionsCOPD is a common and important predisposing comorbidity in patients who develop CAP. COPD often aggravates the clinical symptoms of patients with CAP, complicating treatment, but generally does not appear to affect prognosis.

Community-Acquired Infections ; epidemiology ; microbiology ; mortality ; Humans ; Pneumonia ; epidemiology ; microbiology ; mortality ; Pseudomonas aeruginosa ; pathogenicity ; Pulmonary Disease, Chronic Obstructive ; epidemiology ; microbiology ; mortality ; Risk Factors ; Streptococcus pneumoniae ; pathogenicity

BACKGROUNDThe accuracy of nasopharyngeal aspirate (NPA) specimens in detecting lower respiratory pathogens remains controversial. The objective of this study was to evaluate the diagnostic accuracy of aspirates (NPAs) specimen in lower respiratory tract infections (LRTIs) in children.

METHODSThe prospective study was designed to collect the data of paired NPAs and bronchoalveolar lavage fluids from children with acute LRTIs from January 2013 to December 2015. All specimens were subjected to pathogen detection: bacterial detection by culture, Mycoplasma pneumoniae (Mp) detection by polymerase chain reaction assay and virus (influenza A and B viruses, parainfluenza virus [PIV] Types 1 and 3, respiratory syncytial virus, and adenovirus) detection by immunofluorescence assay. The diagnostic accuracy analysis of NPAs was stratified by age ≤3 years (n = 194) and >3 years (n = 294).

RESULTSWe collected paired specimens from 488 children. The positive rate of pathogen was 61.6%. For Streptococcus pneumoniae, NPA culture had the specificity of 89.9% and negative predictive value of 100% in age ≤3 years, the specificity of 97.2% and negative predictive value of 98.9% in age >3 years. For Mp, the positive predictive values of NPA was 77.4% in children ≤3 years, and 89.1% in children >3 years. For PIV III, NPA specimen had the specificity of 99.8% and negative predictive value of 96.5% in children ≤3 years. For adenovirus, NPA had the specificity of 97.8% and negative predictive value of 98.4% in age ≤3 years, the specificity of 98.9% and negative predictive value of 99.3% in age >3 years.

CONCLUSIONSNPAs are less invasive diagnostic respiratory specimens, a negative NPA result is helpful in "rule out" lower airway infection; however, a positive result does not reliably "rule in" the presence of pathogens.

Acinetobacter baumannii ; isolation & purification ; pathogenicity ; Adolescent ; Child ; Child, Preschool ; Clinical Laboratory Techniques ; methods ; Enterobacter aerogenes ; isolation & purification ; pathogenicity ; Escherichia coli ; isolation & purification ; pathogenicity ; Female ; Haemophilus influenzae ; isolation & purification ; pathogenicity ; Humans ; Infant ; Male ; Nasopharynx ; microbiology ; Prospective Studies ; Pseudomonas aeruginosa ; isolation & purification ; pathogenicity ; Respiratory Tract Infections ; diagnosis ; microbiology ; Sensitivity and Specificity ; Staphylococcus aureus ; isolation & purification ; pathogenicity ; Streptococcus pneumoniae ; isolation & purification ; pathogenicity

OBJECTIVETo evaluate the value of urine sediment analyzer in the screening of clinically suspected urinary tract infection (UTI) in cancer patients.

METHODSThe results of bacterial count of 1 053 midstream urine samples by UF-1000i urine sediment analyzer (UF-1000i urine sediment analyzer, UF-1000i) were compared with the results of bacterial culture. Moreover, the results of distinguishing bacterial species by the bacterial scattergram were compared with the results of bacteria culture. At the same time, the sensitivity, specificity, positive predictive value and negative predictive value of UF-1000i analyzer for UTI screening were evaluated.

RESULTSOf all the 1 053 samples, the top three bacteria were E. coli, Enterococci and P. aeruginosa. The top three malignant tumors of UTI were bladder, lung cancer and cervical cancers. The positive rate of UF-1000i analyzer was 20% (211/1 053), and that of bacteria culture was 17.9% (188/1 053). There was statistically no significant difference in the positive rates between the two methods (χ(2)=1.636, P>0.05), and the two methods had a considerable consistency (Kappa=0.756). Compared with the clinical diagnosis, UTI screening by UF-1000i analyzer showed a sensitivity of 79.6% (160/201), specificity of 95.5% (814/852), positive predictive value of 80.8% (160/198) and negative predictive value of 95.2%(814/855). The distribution of cocci and bacilli acquired by the bacterial scattergram was basically in accordance with the results of bacterial culture.

CONCLUSIONSBacterial count by UF-1000i analyzer plays an important role in early screening of UTI, and the bacterial scattergram may help to distinguish bacterial species, providing reference for the use of antibiotics in early medication.

Bacterial Load ; Enterococcus ; isolation & purification ; Escherichia coli ; isolation & purification ; Female ; Flow Cytometry ; Humans ; Leukocyte Count ; Lung Neoplasms ; urine ; Predictive Value of Tests ; Pseudomonas aeruginosa ; isolation & purification ; Sensitivity and Specificity ; Urinary Bladder Neoplasms ; urine ; Urinary Tract Infections ; diagnosis ; microbiology ; urine ; Uterine Cervical Neoplasms ; urine

INTRODUCTIONTreatment of acute lymphoblastic leukaemia (ALL) using intensive chemotherapy has resulted in high cure rates but also substantial morbidity. Infective complications represent a significant proportion of treatment-related toxicity. The objective of this study was to describe the microbiological aetiology and clinical outcome of episodes of chemotherapy-induced febrile neutropaenia in a cohort of children treated for ALL at our institution.

MATERIALS AND METHODSPatients with ALL were treated with either the HKSGALL93 or the Malaysia-Singapore (Ma-Spore) 2003 chemotherapy protocols. The records of 197 patients who completed the intensive phase of treatment, defined as the period of treatment from induction, central nervous system (CNS)-directed therapy to reinduction from June 2000 to January 2010 were retrospectively reviewed.

RESULTSThere were a total of 587 episodes of febrile neutropaenia in 197 patients, translating to an overall rate of 2.98 episodes per patient. A causative pathogen was isolated in 22.7% of episodes. An equal proportion of Gram-positive bacteria (36.4%) and Gram-negative bacteria (36.4%) were most frequently isolated followed by viral pathogens (17.4%), fungal pathogens (8.4%) and other bacteria (1.2%). Fungal organisms accounted for a higher proportion of clinically severe episodes of febrile neutropaenia requiring admission to the high-dependency or intensive care unit (23.1%). The overall mortality rate from all episodes was 1.5%.

CONCLUSIONFebrile neutropaenia continues to be of concern in ALL patients undergoing intensive chemotherapy. The majority of episodes will not have an identifiable causative organism. Gram-positive bacteria and Gram-negative bacteria were the most common causative pathogens identified. With appropriate antimicrobial therapy and supportive management, the overall risk of mortality from febrile neutropaenia is extremely low.

Candidiasis ; epidemiology ; Chemotherapy-Induced Febrile Neutropenia ; epidemiology ; microbiology ; Child ; Cohort Studies ; Escherichia coli Infections ; epidemiology ; Gram-Negative Bacterial Infections ; epidemiology ; Gram-Positive Bacterial Infections ; epidemiology ; Humans ; Influenza, Human ; epidemiology ; Klebsiella Infections ; epidemiology ; Mycoses ; epidemiology ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; Pseudomonas Infections ; epidemiology ; Retrospective Studies ; Singapore ; epidemiology ; Staphylococcal Infections ; epidemiology ; Virus Diseases ; epidemiology

Lung ; pathology ; Pneumoconiosis ; microbiology ; Pseudomonas Infections ; microbiology ; Pseudomonas aeruginosa