Polyhydroxybutyrate and polyhydroxydodecanoate produced by Burkholderia contaminans IPT553

AIMS

In this paper, we introduce a new Burkholderia contaminans capable of producing a newly characterized polymer.

METHODS AND RESULTS

CG-MS and magnetic nuclear resonance ¹ H and ¹³ C were used to determine the constitution of polymers produced in glucose, glucose with casein, sucrose and sucrose with casein. Three pairs of primers were used to find the polyhydroxyalkanoates (PHA) synthase class and sequence. The synthesized polymers were composed by short-chain length PHA (scl-PHA), especially polyhydroxybutyrate (PHB), and medium chain length PHA (mcl-PHA), especially polyhydroxydodecanoate (PHDd), and their concentration, constitution and molecular weight depend on carbon source used. The bacterium showed only class I synthase which could not explain the mcl-PHA production.

CONCLUSIONS

Burkholderia contaminans has a class I PHA synthase and produces PHB combined to PHDd when cultivated in sucrose or glucose, and PHDd concentration is affected when casein is used.

SIGNIFICANCE AND IMPACT OF THE STUDY

PHA are natural polymers produced by a wide range of bacteria. The presence of PHDd monomers confers to the polymer elastomeric properties. Previously, PHDd was only obtained when bacteria were cultivated in related carbon source. In this work, B. contaminansIPT553 produced PHB with PHDd using simple and low-cost carbon sources that can make possible the cheaper production of a more flexible biopolymer with crystallinity and elasticity different from the more common PHAs.

Relationship Between Pathological Findings and Cholinesterase Activity and Nitric Oxide Levels in Cattle Infected Naturally by Eurytrema coelomaticum

The aim of this study was to evaluate the role of butyrylcholinesterase (BChE) (in the serum and pancreas), acetylcholinesterase (AChE) (in the whole blood and pancreas) and nitric oxide (NO) (in the serum and pancreas) in cattle infected naturally by Eurytrema coelomaticum. Fifty-one cattle were studied, including 33 infected by E. coelomaticum and 18 uninfected animals. Significantly greater AChE activity was found in the pancreas of infected animals (P <0.01); however, these cattle had lower AChE activity in whole blood. BChE activity was greater in the sera of infected animals (P = 0.05), but was less in pancreatic samples. NO levels were significantly higher in the sera (P <0.05) and pancreas (P <0.001) of infected cattle compared with uninfected animals. A positive correlation was found between AChE activity in the pancreas and parasite load, but there was negative correlation between pancreatic BChE activity and parasitic load. Expression of AChE, BChE and NO is therefore linked to the inflammation caused by E. coelomaticum in cattle.

Diagnosis of canine leishmaniasis in the endemic area of Belo Horizonte, Minas Gerais, Brazil by parasite, antibody and DNA detection assays

Canine leishmaniasis caused by Leishmania chagasi (L. infantum) is found throughout the South American continent, including Brazil, and dogs are considered to be the main reservoir host for this parasite. To support the implementation of a diagnostic protocol for surveillance of the disease in the region of Belo Horizonte (Minas Gerais, Brazil) we have compared the sensitivity and specificity of two serological tests, indirect immunofluorescent antibody test (IFAT) and direct agglutination test (DAT), with the combination of direct microscopy-culture-PCR as the gold standard, using samples obtained from 103 dogs in the city of Belo Horizonte, Minas Gerais. The currently used standard serodiagnostic test, IFAT, had a sensitivity of 100% and its specificity was 74% compared to the gold standard of the study. The sensitivity and specificity of the DAT were 100% and 91%, respectively. On the basis of this study it is recommended to change from the IFAT to DAT for the serodiagnosis of canine leishmaniasis because of the superior specificity of the test combined with its user-friendliness.

Development of a fast agglutination screening test (FAST) for the detection of anti-Leishmania antibodies in dogs

A fast agglutination screening test (FAST) for the detection of anti-Leishmania antibodies in serum samples from dogs with visceral leishmaniosis was developed. The test is based on the direct agglutination test (DAT), but combines a higher parasite concentration with a smaller test volume. In contrast to the DAT, the FAST makes use of only one serum dilution and the results can be read within 3 h as opposed to 18-20 h for the DAT. The FAST was evaluated using serum samples of confirmed cases of the disease and healthy controls collected in the most important endemic regions of canine visceral leishmaniosis, import cases of canine leishmaniosis in a non-endemic country, from non-endemic healthy controls and from dogs with other diseases. The performance of the FAST was compared with standard DAT. In the present study, the FAST had a sensitivity of 93.6% and a specificity of 89.0%. The DAT had a sensitivity of 88.6% and a specificity of 96.7%. Furthermore, using a large panel of serum samples of previously examined DAT positive or negative dogs it was shown that degree of agreement between the two tests was high (95.7%; kappa value = 0.91). The FAST offers the advantages of the DAT based on freeze-dried antigen with respect to stability of the antigen, sensitivity and specificity. Moreover, the FAST allows the rapid screening of a large number of samples, which makes the test very useful for epidemiological screening of large populations of dogs.

Epidemiological studies of an outbreak of cutaneous leishmaniasis in the Rio Jequitinhonha Valley, Minas Gerais, Brazil

We detected an outbreak of American cutaneous leishmaniasis in the Jequitinhonha River Valley, Minas Gerais, Brazil. Clinical and epidemiological aspects were studied for a period of two years. Data include results of physical examinations, Montenegro skin test and serology. In total 72 of the 299 individuals evaluated presented active lesions. Only one case out of these 72 patients showed the mucosal form of the disease. The precarious sanitary conditions, low educational level and low income found in the population studied demonstrated that, as with the other parasitic diseases, cutaneous leishmaniasis occurs with greater frequency in needy populations. A canine serological survey detected 20.3% (30/148) of dogs reactive to the Leishmania antigen. Lutzomyia intermedia was the predominant phlebotomine species and the majority of the specimens (84.9%) were captured in the peridomicile. Four samples from human and three from canine cases were isolated and characterised by PCR and isoenzymes as being Leishmania (Viannia) braziliensis. The peridomiciliary nature of the disease is discussed.

Primary aortoenteric fistula related to septic aortitis

CONTEXT

Primary aortoenteric fistulas usually result from erosion of the bowel wall due to an associated abdominal aortic aneurysm. A few patients have been described with other etiologies such as pseudoaneurysm originating from septic aortitis caused by Salmonella.

OBJECTIVE

To present a rare clinical case of pseudoaneurysm caused by septic aortitis that evolved into an aortoenteric fistula.

CASE REPORT

A 65-year-old woman was admitted with Salmonella bacteremia that evolved to septic aortitis. An aortic pseudoaneurysm secondary to the aortitis had eroded the transition between duodenum and jejunum, and an aortoenteric fistula was formed. In the operating room, the affected aorta and intestinal area were excised and an intestine-to-intestine anastomosis was performed. The aorta was sutured and an axillofemoral bypass was carried out. In the intensive care unit, the patient had a cardiac arrest that evolved to death.

Aortoesophageal fistula caused by aneurysm of the thoracic aorta: successful surgical treatment, case report, and literature review

Aortoesophageal fistula induced by atherosclerotic thoracic aortic aneurysm is rare, but is usually a fatal disorder, with few survivors reported. We report the case of a 72-year-old man with aortoesophageal fistula successfully treated in a two-stage operation. In the first stage, we performed resection and replacement of the aortic aneurysm with a prosthetic graft in situ, esophagectomy, cervical esophagostomy, and jejunostomy. After the patient recovered well postoperatively, a transmediastinal retrosternal interposition of the stomach was performed, with esophagogastroanastomosis in the cervical area, to re-establish the gastrointestinal tract. We include a discussion of the causes, diagnostic approach, management of the aorta and esophagus, and review of the literature.

Variation of infrarenal aortic diameter: A necropsy study

PURPOSE

To determine anatomicomorphological changes in the infrarenal portion of the abdominal aorta, we performed 645 dissections of the segment in corpses undergoing necropsy.

METHODS

The aortas were removed from the corpses with a surgical technique; by means of a device that we designed, the external diameter of the artery was measured after luminal pressure was reestablished. This way, it was possible to avoid underestimation of the arterial diameter postmortem. The influence of age, sex, body size, arterial hypertension, chronic obstructive pulmonary disease, and coronary disease on the aortic diameter and the influence of different degrees of sclerosis on the infrarenal aorta wall were analyzed. Considering the diameters, aortas were regarded as "normal" when they did not present any ectasia, arteriomegaly, aneurysm, or hypoplasia.

RESULTS

The sample involved 645 subjects whose ages ranged from 19 to 97 years (mean age, 55.8 years). Of the 645 subjects, 65.5% (423) were men, 34.5% (222) were women, 81% (523) were white, and 19% (122) were of another race. The diameters of arteries showing no anomalous dilatation (ectasis, arteriomegaly, or aneurysm) varied according to subject age, sex, body length, and the degree of atherosclerosis on the aorta wall (P <.01). Aortic diameters of those subjects with arterial hypertension, coronary disease, and chronic obstructive pulmonary disease were compared with the aortic diameters of control subjects, and significant differences were not shown (P >.05). Twenty-nine aneurysms were found (4.5% prevalence). Four were ruptured aneurysms, and all occurred in aortas with diameters larger than 5.0 cm.

CONCLUSION

The infrarenal aortic diameter enlarges with aging, and this enlargement occurs earlier in men than in women. Those subjects who had a longer body length and advanced sclerosis on the aorta wall had larger aortic diameters. There was a high prevalence of infrarenal aneurysms (4.5%), with rupture found solely in aortas with diameters larger than 5.0 cm.

Haematopoietic response and bcl-2 expression in patients with acute myeloid leukaemia

Bcl-2 expression, the number of apoptotic cells and the growth and differentiation of early bone marrow progenitor cells were studied in patients with confirmed diagnosis of acute myeloid leukaemia (AML). Bone marrow cells from normal individuals were used as controls. We observed an increased percentage of bcl-2-mononuclear bone marrow cells expression in AML patients in relation to controls (p =0.002). Accordingly, the number of apoptotic cells was reduced (p = 0.001) and there was a negative correlation between bcl-2 expression and the number of apoptotic cells (r=-0.664, p<0.001). In addition, bcl-2 expression was significantly increased in the chemotherapy resistant group in relation to the responsive group (p = 0.03). Lower rate of survival was observed in the group of AML patients with autonomous proliferation (p=0.01). These results suggest that a high bcl-2 expression and the presence of autonomous proliferation are related to a poor prognosis in AML.