To investigate the characteristics and metabolic mechanism of short-cut denitrifying phospho- rus-removing bacteria （SDPB） that are capable of enhanced biological phosphorus removal （EBPR） using nitrite as an elec...To investigate the characteristics and metabolic mechanism of short-cut denitrifying phospho- rus-removing bacteria （SDPB） that are capable of enhanced biological phosphorus removal （EBPR） using nitrite as an electron acceptor, an aerobic/anoxic sequencing batch reactor was operated under three phases. An SDPB-strain YC was screened after the sludge enrichment and was identified by morphological, physiological, biochemical properties and 16S rDNA gene sequence analysis. Denitrifying phosphorus-removing experiments were conducted to study anaerobic and anoxic metabolic mechanisms by analyzing the changes of chemical oxygen demand （COD）, phosphate, nitrite, poly-fl-hydroxybutyrate （PHB）, and glycogen. The results show that strain YC is a non-fermentative SDPB similar to Paracoccus denitrificans. As a kind of non-fermentative bacteria, the energy of strain YC was mainly generated from phosphorus release （96.2%） under anaerobic conditions with 0.32 mg P per mg synthesized PHB. Under anoxic conditions, strain YC accumulated 0.45 mg P per mg degraded PHB, which produced most of energy for phosphate accumulation （91.3%） and a little for glycogen synthesis （8.7%）. This metabolic mechanism of strain YC is different from that of traditional phosphorus-accumulating organisms （PAOs）. It is also found that PHB, a kind of intracellular polymer, plays a very important role in denitrifying and accumulating phosphorus by supplying sufficient energy for phosphorous accumulation and carbon sources for denitrification. Therefore, monitoring AP/APHB and ANO2 -N/APHB is more necessary than monitoring AP/ACOD, ANO2 -N/ACOD, or AP / ANO2 -N.展开更多
This prospective study was carried out to assess the sensitivity and resistance pattern of lactose non-fermenting Escherichia coli from July 2018 to December 2018 in the Laboratory of Microbiology at Luanda Medical Ce...This prospective study was carried out to assess the sensitivity and resistance pattern of lactose non-fermenting Escherichia coli from July 2018 to December 2018 in the Laboratory of Microbiology at Luanda Medical Center, Angola. Out of 1170 patient, a total of 120 urine specimens infected with Escherichia coli (>105 CFU/ml) were collected according to the routine protocol of urinalysis. Among these 120 isolates, 25 (21%) isolates were determined as “atypical”, lactose non-fermenting E. colis trains. The twenty-five lactose non-fermenting Escherichia coli strains isolated from urine samples in Luanda Medical Center were declared as Multiple Drugs-Resistant strains with high resistance to Cefalexine (100%), Cefuroxime (100%), Ceftriaxone (92%), Gentamycin (92%), Ciprofloxacin (72%) and Amoxiciclin/Clavulanic (80%). The alarming resistance level to the first-choice drugs for the treatment of urinary tract infections caused by non-fermentative lactose E. coli was observed.展开更多
BACKGROUND:Cerebral stroke is a disease with a high disability rate and a high fatality rate.This study was undertaken to assess the risk of stroke associated pneumonia(SAP) in patients with ischemic stroke using A2DS...BACKGROUND:Cerebral stroke is a disease with a high disability rate and a high fatality rate.This study was undertaken to assess the risk of stroke associated pneumonia(SAP) in patients with ischemic stroke using A2DS2 score.METHODS:Altogether 1 279 patients with ischemic stroke who were treated in our department from 2009 to 2011 were retrospectively analyzed with A2DS2 score. A2DS2 score was calculated as follows:age ≥75 years=1,atrial fi brillation=1,dysphagia=2,male sex=1; stroke severity:NIHSS score 0–4=0,5–15=3,≥16=5. The patients were divided into three groups according to A2DS2 score:620 in score 0 group,383 in score 1–9 group,and 276 in score ≥10 group. The three groups were comparatively analyzed. The diagnostic criteria for SAP were as follows:newly emerging lesions or progressively infiltrating lesions on post-stroke chest images combined with more than two of the following clinical symptoms of infection:(1) fever ≥38 °C;(2) newly occurred cough,productive cough or exacerbation of preexisting respiratory tract symptoms with or without chest pain;(3) signs of pulmonary consolidation and/or wet rales;(4) peripheral white blood cell count ≥10×109/L or ≤4×109/L with or without nuclear shift to left,while excluding some diseases with clinical manifestations similar to pneumonia,such as tuberculosis,pulmonary tumors,non-infectious interstitial lung disease,pulmonary edema,pulmonary embolism and atelectasis. The incidence and mortality of SAP as well as the correlation with ischemic stroke site were analyzed in the three groups respectively. Mean± standard deviation was used to represent measurement data with normal distribution and Student's t test was used. The chi-square test was used to calculate the percentage for enumeration data.RESULTS:The incidence of SAP was significantly higher in the A2DS2 score≥10 group than that in the score 1–9 and score 0 groups(71.7% vs. 22.7%,71.7% vs. 3.7%,respectively),whereas the mortality in the score≥10 group was significantly higher than that in the score 1–9 and score 0 groups(16.7% vs. 4.96%,16.7% vs. 0.3%,respectively). The incidences of cerebral infarction in posterior circulation and cross-MCA,ACA distribution areas were signif icantly higher than those in the SAP group and in the non-SAP group(35.1% vs.10.1%,11.4% vs. 7.5%,respectively). The incidence of non-fermentative bacteria infection was signifi cantly increased in the score≥10 group.CONCLUSIONS:A2DS2 score provides a basis for risk stratifi cation of SAP. The prevention of SAP needs to be strengthened in acute ischemic stroke patients with a A2DS2 score≥10.展开更多
AIM: To explore the association between AT-rich interactive domain 1A (ARID1A) protein loss by immunohistochemistry and both clinicopathologic characteristics and prognosis in patients with colorectal cancer.
Background: Chromobacterium violaceum is a Gram-negative, a facultative anaerobe bacteria producing violacein pigment. C. violaceum is generally present as the normal flora of water and soil. The Urine Tract Infection...Background: Chromobacterium violaceum is a Gram-negative, a facultative anaerobe bacteria producing violacein pigment. C. violaceum is generally present as the normal flora of water and soil. The Urine Tract Infection (UTI) due to C. violaceum is very rare. Until now there was no report from Africa about UTIs caused by C. violaceum. The antimicrobial susceptibility pattern of C. violaceum is very limited due to the rarity of isolation from clinical specimens. Here, we describe the first case of urinary tract infection caused by C. violaceum in Angola. Aim: Our case report was carried out to assess the sensitivity and resistance pattern of C. violaceum as the causative agent of UTI. Results: C. violaceum was sensitive to Amoxicillin/Clavulanic acid, Ceftriaxon, Ciprofloxacin, Doxycycline, Trimethoprim/Sulfamethoxazole, Piperacilin/Tazobactam, Gentamicin, Amikacin, Aztreonam and imipenem. The bacteria showed resistance to Cefuroxime. Conclusion: Here, we report a rare case of complicate urinary tract infection caused by C. violaceum in patient, who was treated successfully with ciprofloxacin for a total duration of 7 days.展开更多
Background and Aim: Multi drug resistant Non fermenting gram negative bacilli (NFGNB) have emerged as a major cause of health-care associated infections especially in immunocompromised hosts. The aim of the study was ...Background and Aim: Multi drug resistant Non fermenting gram negative bacilli (NFGNB) have emerged as a major cause of health-care associated infections especially in immunocompromised hosts. The aim of the study was to investigate the prevalence of NFGNB as a cause of health-care associated infections (HAI) in cancer patients and determine their resistance pattern. Patients and Methods: During the study period, 158 NFGNB isolates were collected. Microscan Walk Away 9 was used for identification and testing for the metallo-β-lactamases (MBLs) was done by Imipenem-EDTA combined disk synergy test (CDST-IPM). Results: NFGNB represented 29.0% of infections caused by gram negative organisms. Carbapenem resistance, the multi-drug resistant (MDR) phenotype, and MBL production were documented in 70%, 63%, and 59% of NFGNB isolates, respectively. MDR-NFGNB rates were significantly higher among hospitalized patients, medical department and those with longer duration of hospital stay (p = 0.034, 0.026, 0.019;respectively) than non MDR-NFGNB. Conclusion: A high level of carbapenem and multi-drug resistance were detected among the non-fermenter pathogens isolated from hospitalized cases and were more frequently encountered in high risk adult cancer patients requiring longer duration of hospitalization. The MDR-NFGNB are constituting important causes of health-care associated infections in cancer patients.展开更多
Plant growth and development are tightly controlled in response to environmental conditions that influence the availability of photosynthetic carbon in the form of sucrose. Trehalose-6-phosphate （T6P）, the precursor...Plant growth and development are tightly controlled in response to environmental conditions that influence the availability of photosynthetic carbon in the form of sucrose. Trehalose-6-phosphate （T6P）, the precursor of trehalose in the biosynthetic pathway, is an important signaling metabolite that is involved in the regulation of plant growth and development in response to carbon availability. In addition to the plant＇s own pathway for trehalose synthesis, formation of T6P or trehalose by pathogens can result in the reprogramming of plant metabolism and development. Developmental processes that are regulated by T6P range from embryo development to leaf senescence. Some of these processes are regulated in interaction with phytohormones, such as auxin. A key interacting factor of T6P signaling in response to the environment is the protein kinase sucrose non-fermenting related kinase-1 （SnRK1）, whose catalytic activity is inhibited by T6R SnRK1 is most likely involved in the adjustment of metabolism and growth in response to starvation. The transcription factor bZlP11 has recently been identified as a new player in the T6P/SnRK1 regulatory pathway. By inhibiting SnRK1, T6P promotes biosynthetic reactions. This regulation has important consequences for crop production, for example, in the developing wheat grain and during the growth of potato tubers.展开更多
基金Supported by the Nafional Natural Science Foundation of China （51078008）, the Natural Science Foundation of Guangdong Province （06022869, 07003251）, and the National Key Scientific and Technological Project Water Pollution Control and Treatment （2008ZX07211-003, 2009ZX07314-009-003）.
文摘To investigate the characteristics and metabolic mechanism of short-cut denitrifying phospho- rus-removing bacteria （SDPB） that are capable of enhanced biological phosphorus removal （EBPR） using nitrite as an electron acceptor, an aerobic/anoxic sequencing batch reactor was operated under three phases. An SDPB-strain YC was screened after the sludge enrichment and was identified by morphological, physiological, biochemical properties and 16S rDNA gene sequence analysis. Denitrifying phosphorus-removing experiments were conducted to study anaerobic and anoxic metabolic mechanisms by analyzing the changes of chemical oxygen demand （COD）, phosphate, nitrite, poly-fl-hydroxybutyrate （PHB）, and glycogen. The results show that strain YC is a non-fermentative SDPB similar to Paracoccus denitrificans. As a kind of non-fermentative bacteria, the energy of strain YC was mainly generated from phosphorus release （96.2%） under anaerobic conditions with 0.32 mg P per mg synthesized PHB. Under anoxic conditions, strain YC accumulated 0.45 mg P per mg degraded PHB, which produced most of energy for phosphate accumulation （91.3%） and a little for glycogen synthesis （8.7%）. This metabolic mechanism of strain YC is different from that of traditional phosphorus-accumulating organisms （PAOs）. It is also found that PHB, a kind of intracellular polymer, plays a very important role in denitrifying and accumulating phosphorus by supplying sufficient energy for phosphorous accumulation and carbon sources for denitrification. Therefore, monitoring AP/APHB and ANO2 -N/APHB is more necessary than monitoring AP/ACOD, ANO2 -N/ACOD, or AP / ANO2 -N.
文摘This prospective study was carried out to assess the sensitivity and resistance pattern of lactose non-fermenting Escherichia coli from July 2018 to December 2018 in the Laboratory of Microbiology at Luanda Medical Center, Angola. Out of 1170 patient, a total of 120 urine specimens infected with Escherichia coli (>105 CFU/ml) were collected according to the routine protocol of urinalysis. Among these 120 isolates, 25 (21%) isolates were determined as “atypical”, lactose non-fermenting E. colis trains. The twenty-five lactose non-fermenting Escherichia coli strains isolated from urine samples in Luanda Medical Center were declared as Multiple Drugs-Resistant strains with high resistance to Cefalexine (100%), Cefuroxime (100%), Ceftriaxone (92%), Gentamycin (92%), Ciprofloxacin (72%) and Amoxiciclin/Clavulanic (80%). The alarming resistance level to the first-choice drugs for the treatment of urinary tract infections caused by non-fermentative lactose E. coli was observed.
文摘BACKGROUND:Cerebral stroke is a disease with a high disability rate and a high fatality rate.This study was undertaken to assess the risk of stroke associated pneumonia(SAP) in patients with ischemic stroke using A2DS2 score.METHODS:Altogether 1 279 patients with ischemic stroke who were treated in our department from 2009 to 2011 were retrospectively analyzed with A2DS2 score. A2DS2 score was calculated as follows:age ≥75 years=1,atrial fi brillation=1,dysphagia=2,male sex=1; stroke severity:NIHSS score 0–4=0,5–15=3,≥16=5. The patients were divided into three groups according to A2DS2 score:620 in score 0 group,383 in score 1–9 group,and 276 in score ≥10 group. The three groups were comparatively analyzed. The diagnostic criteria for SAP were as follows:newly emerging lesions or progressively infiltrating lesions on post-stroke chest images combined with more than two of the following clinical symptoms of infection:(1) fever ≥38 °C;(2) newly occurred cough,productive cough or exacerbation of preexisting respiratory tract symptoms with or without chest pain;(3) signs of pulmonary consolidation and/or wet rales;(4) peripheral white blood cell count ≥10×109/L or ≤4×109/L with or without nuclear shift to left,while excluding some diseases with clinical manifestations similar to pneumonia,such as tuberculosis,pulmonary tumors,non-infectious interstitial lung disease,pulmonary edema,pulmonary embolism and atelectasis. The incidence and mortality of SAP as well as the correlation with ischemic stroke site were analyzed in the three groups respectively. Mean± standard deviation was used to represent measurement data with normal distribution and Student's t test was used. The chi-square test was used to calculate the percentage for enumeration data.RESULTS:The incidence of SAP was significantly higher in the A2DS2 score≥10 group than that in the score 1–9 and score 0 groups(71.7% vs. 22.7%,71.7% vs. 3.7%,respectively),whereas the mortality in the score≥10 group was significantly higher than that in the score 1–9 and score 0 groups(16.7% vs. 4.96%,16.7% vs. 0.3%,respectively). The incidences of cerebral infarction in posterior circulation and cross-MCA,ACA distribution areas were signif icantly higher than those in the SAP group and in the non-SAP group(35.1% vs.10.1%,11.4% vs. 7.5%,respectively). The incidence of non-fermentative bacteria infection was signifi cantly increased in the score≥10 group.CONCLUSIONS:A2DS2 score provides a basis for risk stratifi cation of SAP. The prevention of SAP needs to be strengthened in acute ischemic stroke patients with a A2DS2 score≥10.
基金Supported by National High Technology Research and Development Program of China(863 Program),No.2012AA02A506National Natural Science Foundation of China,No.81372570+1 种基金the Science and Technology Foundation of Guangdong Province,China,No.2012B031800088the Science and Technology Foundation of Guangdong Province,China,No.C2011019
文摘AIM: To explore the association between AT-rich interactive domain 1A (ARID1A) protein loss by immunohistochemistry and both clinicopathologic characteristics and prognosis in patients with colorectal cancer.
文摘Background: Chromobacterium violaceum is a Gram-negative, a facultative anaerobe bacteria producing violacein pigment. C. violaceum is generally present as the normal flora of water and soil. The Urine Tract Infection (UTI) due to C. violaceum is very rare. Until now there was no report from Africa about UTIs caused by C. violaceum. The antimicrobial susceptibility pattern of C. violaceum is very limited due to the rarity of isolation from clinical specimens. Here, we describe the first case of urinary tract infection caused by C. violaceum in Angola. Aim: Our case report was carried out to assess the sensitivity and resistance pattern of C. violaceum as the causative agent of UTI. Results: C. violaceum was sensitive to Amoxicillin/Clavulanic acid, Ceftriaxon, Ciprofloxacin, Doxycycline, Trimethoprim/Sulfamethoxazole, Piperacilin/Tazobactam, Gentamicin, Amikacin, Aztreonam and imipenem. The bacteria showed resistance to Cefuroxime. Conclusion: Here, we report a rare case of complicate urinary tract infection caused by C. violaceum in patient, who was treated successfully with ciprofloxacin for a total duration of 7 days.
文摘Background and Aim: Multi drug resistant Non fermenting gram negative bacilli (NFGNB) have emerged as a major cause of health-care associated infections especially in immunocompromised hosts. The aim of the study was to investigate the prevalence of NFGNB as a cause of health-care associated infections (HAI) in cancer patients and determine their resistance pattern. Patients and Methods: During the study period, 158 NFGNB isolates were collected. Microscan Walk Away 9 was used for identification and testing for the metallo-β-lactamases (MBLs) was done by Imipenem-EDTA combined disk synergy test (CDST-IPM). Results: NFGNB represented 29.0% of infections caused by gram negative organisms. Carbapenem resistance, the multi-drug resistant (MDR) phenotype, and MBL production were documented in 70%, 63%, and 59% of NFGNB isolates, respectively. MDR-NFGNB rates were significantly higher among hospitalized patients, medical department and those with longer duration of hospital stay (p = 0.034, 0.026, 0.019;respectively) than non MDR-NFGNB. Conclusion: A high level of carbapenem and multi-drug resistance were detected among the non-fermenter pathogens isolated from hospitalized cases and were more frequently encountered in high risk adult cancer patients requiring longer duration of hospitalization. The MDR-NFGNB are constituting important causes of health-care associated infections in cancer patients.
文摘Plant growth and development are tightly controlled in response to environmental conditions that influence the availability of photosynthetic carbon in the form of sucrose. Trehalose-6-phosphate （T6P）, the precursor of trehalose in the biosynthetic pathway, is an important signaling metabolite that is involved in the regulation of plant growth and development in response to carbon availability. In addition to the plant＇s own pathway for trehalose synthesis, formation of T6P or trehalose by pathogens can result in the reprogramming of plant metabolism and development. Developmental processes that are regulated by T6P range from embryo development to leaf senescence. Some of these processes are regulated in interaction with phytohormones, such as auxin. A key interacting factor of T6P signaling in response to the environment is the protein kinase sucrose non-fermenting related kinase-1 （SnRK1）, whose catalytic activity is inhibited by T6R SnRK1 is most likely involved in the adjustment of metabolism and growth in response to starvation. The transcription factor bZlP11 has recently been identified as a new player in the T6P/SnRK1 regulatory pathway. By inhibiting SnRK1, T6P promotes biosynthetic reactions. This regulation has important consequences for crop production, for example, in the developing wheat grain and during the growth of potato tubers.
