Isolation, screening, characterization, and optimization of bacteria isolated from calcareous soils for siderophore production.

The most effective agricultural practice to prevent iron deficiency in calcareous soils is fertilizing with synthetic chelates. These compounds are non-biodegradable, and persistent in the environment; hence, there is a risk of leaching metals into the soil horizon. To tackle iron deficiency-induced chlorosis (IDC) in crops grown on calcareous soils, environmentally friendly solutions are needed rather than chemical application as it affects the soil health further. Hence, the present work focused on isolating and screening calcareous soil-specific bacteria capable of producing iron-chelating siderophores. Siderophore-producing bacteria (SPB) was isolated from the groundnut (Arachis hypogea L.) rhizosphere region, collected from Coimbatore district, Tamil Nadu, of which 17 bacterial isolates were positive for siderophore production assayed by chrome azurol sulphonate. The performance of SPB isolates was compared for siderophore kinetics, level of siderophore production, type of siderophore produced and iron-chelating capacity under 15 mM KHCO3. Four best performing isolates were screened, with average siderophores yield ranging ∼60-80% under pH 8, with sucrose as carbon source and NH2SO4 as nitrogen source at 37 °C. The four efficient SPB were molecularly identified as B. licheniformis, B. subtilis, B. licheniformis, and O. grignonense based on 16S rDNA sequencing. The simultaneous inhibition method showed T.viride has the highest antagonistic effect against S.rolfsii, and M.phaseolina with a reduction of mycelial growth by 69.3 and 65.1%, respectively, compared to control. Our results indicate that the optimized conditions enhanced siderophores chelation by suppressing the stem and root rot fungi, which could help in a cost-effective and environmentally friendly manner.

Bilateral upper-lobe cavitary Pneumocystis carinii pneumonia in a patient on dapsone prophylaxis.

Pneumocystis carinii pneumonia (PCP) presenting as bilateral upper-lobe cavitary disease is rare. Isolated upper-lobe involvement has traditionally been associated with aerosolized pentamidine prophylaxis. Dapsone is a cheap and effective prophylactic agent against P carinii in patients who cannot tolerate trimethoprim-sulfamethoxazole. This is a case of a man who presented with bilateral upper-lobe cavitary P carinii pneumonia despite being on dapsone prophylaxis. Bronchoalveolar lavage was negative for P carinii. Transbronchial biopsy was positive for P carinii. The patient improved significantly with radiological resolution on specific treatment for P carinii. PCP should be included in the differential diagnosis of upper-lobe cavitary lung disease, and a transbronchial biopsy should be performed when the diagnosis is suspected.

Cocaine-associated intestinal gangrene in a pregnant woman.

A 31-year-old pregnant woman who was an active cocaine abuser presented to our emergency department five times in 1 week for abdominal pain and vomiting. She continued to use cocaine regularly despite having abdominal pain. Her fifth admission was for seizures. There were no objective signs of peritoneal inflammation and the rectal guiac examination was repeatedly negative. The patient progressed to severe septic shock. Intraabdominal sepsis and/or bowel perforation was suspected. Exploratory laporatomy revealed gangrene and perforation of the small intestine and fecal peritonitis. She rapidly developed multiorgan failure and died. Gastrointestinal complications resulting from cocaine use are uncommon. Our case is unique in that the patient was pregnant, used cocaine by the intranasal route, and lacked objective signs of acute abdomen. Emergency physicians should be aware of the morbidity associated with the use of cocaine.

Pulse oximetry in the evaluation of peripheral vascular disease.

The role of pulse oximetry in the evaluation of peripheral vascular disease (PVD) was investigated. In addition, the value of elevating the limb to improve the sensitivity of detection of PVD by the pulse oximeter was also determined. Pulse oximetry reading in the toes were obtained in 40 young, healthy volunteers and in 40 randomly selected patients referred to the vascular investigation laboratory over a period of two months. All 40 healthy volunteers had normal pulse oximetry readings. Normal pulse oximetry reading in the toes was defined as > 95% O2 Sat and +/-2 of finger pulse oximetry reading. In all 40 patients, pulse oximetry readings were either normal or not detected at all. Since there was no gradation in decrease in the pulse oximetry reading with severity of disease or with elevation of the patient's lower extremity, an absent or no reading was considered as an abnormal result from the test. The frequency of abnormal pulse oximetry readings increased significantly in groups with abnormal ankle-brachial pressure index (ABPI) and also varied significantly with elevation of the patients' lower limbs. In patients with no PVD detected by Doppler (ABPI > 0.9), pulse oximetry readings were normal in all. However, in patients with moderate PVD (ABPI, 0.5-0.9), 84% of the patients' lower limbs had normal pulse oximetry readings and 16% had an abnormal reading at baseline level (flat). An additional 12% of the lower limbs in this group had an abnormal reading on elevation of the limb to 12 inches. In patients with severe PVD (ABPI < 0.5), 54% of the patients' lower limbs had an abnormal reading at baseline and an additional 23% had an abnormal reading at elevation of the limb to 12 inches. In conclusion, pulse oximetry was not a sensitive test for detecting early PVD.

Primary biphasic synovial sarcoma of the pleura.

Synovial sarcoma most commonly occurs in the peri-articular regions of the extremities. The present report describes a rare case of primary biphasic synovial sarcoma of the pleura in an 18-year-old female. The diagnosis was made on the basis of light microscopy, immunohistochemistry, electron microscopy and the characteristic translocation found on cytogenetic analysis. Synovial sarcoma should be included in the differential diagnoses of pleural tumors.