LysR-type transcriptional regulators are involved in the regulation of numerous cellular metabolic processes in Klebsiella pneumoniae, leading to severe infection. Earlier, we found a novel LysR family gene, named kp05372, in a strain of K. pneumoniae (designated GPKP) isolated from forest musk deer. To study the function of this gene in relation to the biological characteristics of GPKP, we used the suicide plasmid and conjugative transfer methods to construct deletion mutant strain GPKP-Δkp05372; moreover, we also constructed the GPKP-Δkp05372+ complemented strain. The role of this gene was determined by comparing the following characteristics of three strains: growth curves, biofilm formation, drug resistance, stress resistance, median lethal dose (LD₅₀), organ colonization ability, and the histopathology of GPKP. Real-time polymerase chain reaction (RT-PCR) was used to test the expression level of seven genes upstream of kp05372. There was no significant difference in the growth rates when comparing the three bacterial strains, and no significant difference was recorded at different osmotic pressures, temperatures, salt contents, or hydrogen peroxide concentrations. The GPKP-Δkp05372 mutant formed a weak biofilm, and the other two strains formed medium biofilm. The drug resistance of the GPKP-Δkp05372 mutant toward cephalothin, cotrimoxazole, and polymyxin B was changed. The acid tolerance of the deletion strain was stronger than that of the other two strains. The LD₅₀ values of the wild-type and complemented strains were 174-fold and 77-fold higher than that of the GPKP-Δkp05372 mutant, respectively. The colonization ability of the GPKP-Δkp05372 mutant in the heart, liver, spleen, kidney, and intestine was the weakest. The three strains caused different histopathological changes in the liver and lungs. In the GPKP-Δkp05372 mutant, the relative expression levels of kp05374 and kp05379 were increased to 1.32-fold and 1.42-fold, respectively, while the level of kp05378 was decreased by 42%. Overall, the deletion of kp05372 gene leads to changes in the following: drug resistance and acid tolerance; decreases in virulence, biofilm formation, and colonization ability of GPKP; and regulation of the upstream region of adjacent genes.
Animals ; Bacterial Proteins/physiology* ; Biofilms ; Deer/microbiology* ; Drug Resistance, Bacterial ; Female ; Klebsiella Infections/pathology* ; Klebsiella pneumoniae/growth & development* ; Male ; Mice ; Transcription Factors/physiology*

Adult ; Aneurysm, False ; diagnostic imaging ; surgery ; Anti-Bacterial Agents ; therapeutic use ; Echocardiography, Transesophageal ; Endocarditis, Bacterial ; diagnostic imaging ; drug therapy ; Female ; Heart Valve Prosthesis Implantation ; Heart Ventricles ; pathology ; Humans ; Mitral Valve ; surgery ; Mitral Valve Insufficiency ; diagnostic imaging ; surgery

INTRODUCTION: In recent years, () has emerged as the predominant cause of pyogenic liver abscess in Asia. - as the causative microorganism in other visceral organ abscesses-is less described. In this study, we seeked to describe the clinical characteristics of visceral organ abscesses in our institution and evaluated the prescription practices of physicians with regard to antibiotic therapy. MATERIALS AND METHODS: A retrospective analysis of patients with culture positive (blood or abscess aspirate) visceral organ abscesses from May 2014 to April 2016 requiring hospitalisation in Changi General Hospital was conducted. RESULTS: A total of 140 adult patients with visceral organ abscesses were identified. The commonest site of involvement was the liver (77.9%), followed by genitourinary tract (20.7%). Diabetic patients were more likely to have liver abscesses, genitourinary abscesses, abscesses in 2 or more organs, genitourinary disease with abscess formation outside of the genitourinary tract, and endovascular infection. Patients with extended spectrum beta-lactamase producing , were more likely to have an obstructive lesion related to the site of the abscess. Overall mortality rate was 7.1%. Amongst survivors, the mean total duration of parenteral antimicrobial therapy was 2.5 weeks before switching to oral antimicrobial agents. CONCLUSION Genitourinary tract is the commonest extra-hepatic site for visceral organ abscess in infections. Parenteral to oral switch of antimicrobial agents appears to be a safe and effective treatment option.
Abscess ; classification ; microbiology ; mortality ; therapy ; Anti-Bacterial Agents ; therapeutic use ; Diabetes Mellitus ; epidemiology ; Female ; Humans ; Klebsiella pneumoniae ; isolation & purification ; Liver ; pathology ; Male ; Middle Aged ; Retrospective Studies ; Risk Factors ; Singapore ; epidemiology ; Survival Analysis ; Urogenital System ; pathology ; Viscera ; pathology

Cases of acute pancreatitis induced by organophosphate intoxication are encountered occasionally in clinics, but very few of them develop into severe pancreas necrosis and irreversible pancreatic function impairment. Here, we report a 47-year-old female organophosphate poisoning case after ingestion of massive insecticides; she was considered to have total necrosis and function failure of the pancreas via serum amylase test, glucose level test, and CT imaging. The patient exhibited no relief under the regular medicine treatment, which included sandostatin, antibiotics, intravenous atropine, and pralidoxime methiodide. She received percutaneous catheterization and drainage of pancreatic zone to expel hazardous necrotic waste, also by which the pathogenic evidence was obtained and the antibiotics were adjusted subsequently. The patient recovered gradually, was discharged after 2 weeks, and was prescribed with oral pancreatin capsules before meals and hypodermic insulin at meals and bedtime to compensate the impaired pancreatic function.
Acute Disease ; Anti-Bacterial Agents ; therapeutic use ; Catheterization ; Female ; Humans ; Insecticides ; poisoning ; Middle Aged ; Organophosphate Poisoning ; Pancreas ; diagnostic imaging ; pathology ; Pancreatin ; therapeutic use ; Pancreatitis ; chemically induced ; diagnostic imaging ; therapy ; Treatment Outcome

BackgroundAntimicrobial de-escalation refers to starting the antimicrobial treatment with broad-spectrum antibiotics, followed by narrowing the drug spectrum according to culture results. The present study evaluated the effect of de-escalation on ventilator-associated pneumonia (VAP) in trauma patients.

MethodsThis retrospective study was conducted on trauma patients with VAP, who received de-escalation therapy (de-escalation group) or non-de-escalation therapy (non-de-escalation group). Propensity score matching method was used to balance the baseline characteristics between both groups. The 28-day mortality, length of hospitalization and Intensive Care Unit stay, and expense of antibiotics and hospitalization between both groups were compared. Multivariable analysis explored the factors that influenced the 28-day mortality and implementation of de-escalation.

ResultsAmong the 156 patients, 62 patients received de-escalation therapy and 94 patients received non-de-escalation therapy. No significant difference was observed in 28-day mortality between both groups (28.6% vs. 23.8%, P = 0.620). The duration of antibiotics treatment in the de-escalation group was shorter than that in the non-de-escalation group (11 [8-13] vs. 14 [8-19] days, P = 0.045). The expenses of antibiotics and hospitalization in de-escalation group were significantly lower than that in the non-de-escalation group (6430 ± 2730 vs. 7618 ± 2568 RMB Yuan, P = 0.043 and 19,173 ± 16,861 vs. 24,184 ± 12,039 RMB Yuan, P = 0.024, respectively). Multivariate analysis showed that high Acute Physiology and Chronic Health Evaluation II (APACHE II) score, high injury severity score, multi-drug resistant (MDR) infection, and inappropriate initial antibiotics were associated with patients' 28-day mortality, while high APACHE II score, MDR infection and inappropriate initial antibiotics were independent factors that prevented the implementation of de-escalation.

ConclusionsDe-escalation strategy in the treatment of trauma patients with VAP could reduce the duration of antibiotics treatments and expense of hospitalization, without increasing the 28-day mortality and MDR infection.

APACHE ; Anti-Bacterial Agents ; therapeutic use ; Female ; Humans ; Intensive Care Units ; Male ; Pneumonia, Ventilator-Associated ; drug therapy ; pathology ; Propensity Score ; Retrospective Studies

Chlortetracycline (CTC), one kind of common antibiotic for prevention and treatment of various diseases, also exhibits good performance in accelerating the growth of livestock. Macleaya cordata, a traditional Chinese medicine, is usually used as a natural additive in livestock because of its anti-microbial, anti-fungal, anti-inflammatory, and pesticidal activity. In this work, we studied whether M. cordata helps regulate the growth-promoting effect of CTC on broiler chickens. It is demonstrated that M. cordata improves the growth-promoting effect of CTC on growth performance indices of broiler chickens, such as survival rate, daily weight, and feed to weight rate. M. cordata also delays the maximum of CTC residues in plasma. It may depend on the higher values of operational taxonomic unit (OTU) and the indices of α diversity driven by simultaneous use of CTC and M. cordata.
Animals ; Anti-Bacterial Agents/pharmacology* ; Chickens/growth & development* ; Chlortetracycline/pharmacology* ; Drugs, Chinese Herbal/pharmacology* ; Duodenum/pathology* ; Female ; Gastrointestinal Microbiome ; Male ; Medicine, Chinese Traditional

Acinetobacter baumannii (A. Baumannii) is an emerging opportunistic pathogen responsible for hospital-acquired infections, and which now constitutes a sufficiently serious threat to public health to necessitate the development of an effective vaccine. In this study, a recombinant fused protein named OmpK/Omp22 and two individual proteins OmpK and Omp22 were obtained using recombinant expression and Ni-affinity purification. Groups of BALB/c mice were immunized with these proteins and challenged with a clinically isolated strain of A. baumannii. The bacterial load in the blood, pathological changes in the lung tissue and survival rates after challenge were evaluated. Mice immunized with OmpK/Omp22 fused protein provided significantly greater protection against A. baumannii challenge than those immunized with either of the two proteins individually. The results provide novel clues for future design of vaccines against A. baumannii.
Acinetobacter Infections ; pathology ; prevention & control ; Acinetobacter baumannii ; genetics ; immunology ; Animals ; Antibodies, Bacterial ; blood ; Bacterial Load ; Bacterial Outer Membrane Proteins ; genetics ; immunology ; Bacterial Vaccines ; immunology ; Disease Models, Animal ; Female ; Mice, Inbred BALB C ; Pneumonia, Bacterial ; pathology ; prevention & control ; Recombinant Fusion Proteins ; genetics ; immunology

BACKGROUNDStevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening diseases with high mortality rates. This study was designed to analyze the pathogenic factors, clinical manifestations, complications, treatment, and prognosis of SJS/TEN and to explore the differences between surviving and deceased patients.

METHODSSJS/TEN patients admitted to Beijing Friendship Hospital from January 2006 to December 2015 were included in the study. Patients' data were retrospectively analyzed. Comparative studies were performed on the survival group and the deceased group, and Fisher's exact probability test was used for statistical analysis.

RESULTSAmong the 88 patients included, 40 (45.5%) were male with a mean age of 45 ± 18 years. Forty-eight (54.5%) had SJS, 34 (38.6%) had SJS/TEN, and 6 (6.8%) had TEN. Fifty-three (60.2%) cases were caused by medications, mainly antibiotics (n = 24) followed by traditional Chinese medicines (n = 7). Forty-two cases (47.7%) developed visceral damage. Eighty-two patients improved or recovered and were discharged from hospital, and six patients died. Comparative studies on the survival group and the deceased group showed that the presence of malignant tumor ( χ2 = 27.969,P < 0.001), connective tissue diseases ( χ2 = 9.187, P= 0.002), previous abnormal liver/kidney functions ( χ2 = 6.006, P= 0.014), heart rate >100 times/min ( χ2 = 6.347, P= 0.012), detached skin area >20% ( χ2 = 5.594, P= 0.018), concurrent mucosal involvement at the mouth, eyes, and external genitals ( χ2 = 4.945, P= 0.026), subsequent accompanying liver/kidney damage ( χ2 = 11.839, P= 0.001, and χ2 = 36.302,P < 0.001, respectively), and SCORTEN score >2 ( χ2 = 37.148,P < 0.001) increased the risk of death.

CONCLUSIONSSJS/TEN is mainly caused by medications, and nearly half of patients develop visceral damage. Multiple factors increase the mortality risk.

Adult ; Anti-Bacterial Agents ; therapeutic use ; Connective Tissue Diseases ; metabolism ; pathology ; Eye ; pathology ; Female ; Genitalia ; pathology ; Humans ; Kidney ; metabolism ; pathology ; Liver ; metabolism ; pathology ; Male ; Middle Aged ; Mouth ; pathology ; Retrospective Studies ; Skin ; metabolism ; pathology ; Stevens-Johnson Syndrome ; drug therapy ; metabolism ; pathology

The severity of systemic lupus erythematosus (SLE) patients with pulmonary bacterial infection varies widely. We investigated the significance of procalcitonin (PCT) and C-reactive protein (CRP) in evaluating the severity of pulmonary infection in SLE patients. This retrospective study contained a total of 117 patients (107 women and 10 men) with SLE from January 2010 to June 2011. Serum levels of PCT and CRP were measured by enzyme-linked immunosorbent assay. The severity of pulmonary bacterial infection (PBI) was evaluated using the pneumonia severity index (PSI). SLE patients with PBI, particularly those with bacterial isolates, had significantly higher levels of serum PCT and CRP than those without PBI. Serum PCT and CRP were not associated with SLE disease activity, but positively with the values of PSI in active SLE patients with PBI. Serum levels of PCT and CRP may be additional biomarkers in evaluating the severity of PBI in lupus patients.
Aged ; Bacterial Infections ; blood ; microbiology ; pathology ; C-Reactive Protein ; metabolism ; Calcitonin ; blood ; Female ; Humans ; Lung ; microbiology ; pathology ; Lupus Erythematosus, Systemic ; blood ; complications ; pathology ; Male ; Severity of Illness Index

This study aimed to provide evidence of persistent uropathogenic Escherichia coli (UPEC) in female patients with recurrent urinary tract infection (UTI) after antibiotic therapy. We collected biopsies of the bladder, and clean-catch urine samples from 32 women who had episodes of recurrent UTI and were given antibiotic therapy. Urine samples and biopsies were analyzed by conventional bacteriological techniques. Phylogenetic group and 16 virulence factors (VFs) of UPEC were determined using polymerase chain reaction (PCR). The infection capability of UPEC was confirmed in a mouse model. Immunofluorescence and electron microscopy were used to detect intracellular bacterial communities (IBCs) in the mouse model. The results showed that all urine specimens were detected sterile. E. coli was found in 6 of 32 biopsies (18.75%), and was identified to be UPEC by PCR. Different VFs associated with the formation of IBCs were identified in all six UPEC isolates. Each UPEC isolate was capable of forming IBCs within the bladder epithelial cells of mice. In conclusion, UPEC with distinctive pathological traits and the capability of IBC formation was first found in the bladders of women after antibiotic therapy, suggesting that the IBC pathogenic pathway may occur in humans and it plays an important role in UTI recurrence.
Adult ; Animals ; Anti-Bacterial Agents ; administration & dosage ; Biopsy ; Escherichia coli Infections ; drug therapy ; microbiology ; Female ; Humans ; Mice ; Middle Aged ; Phylogeny ; Urinary Bladder ; drug effects ; microbiology ; pathology ; Uropathogenic Escherichia coli ; drug effects ; genetics ; pathogenicity