Epidemiological Analysis of Salmonella enteritidis Isolates from Humans and Broiler Chickens in Thailand by Phage Typing and Pulsed-Field Gel Electrophoresis

To determine the phage types (PT) of Salmonella enteritidis found in Thailand and to clarify the potential for human infection by S. enteritidis in broiler chicken meat, human and poultry isolates taken from Thailand between 1990 and 1997 were phage typed and analyzed by pulsed-field gel electrophoresis (PFGE). Ten different PT were found among the 302 isolates phage typed, with PT 4 being the most frequent in human (73.9%) and poultry (76.2%) isolates, followed by PT 1 (8.0%), 8 (3.6%), and 7a (2.2%) in human isolates and by PT 7a (4.9%), 1 (3.7%), and 12 (2.4%) in poultry isolates. Of the 53 isolates analyzed by PFGE, 45 showed an indistinguishable pattern (pattern A) by BlnI-digested PFGE and the other 8 isolates showed a very similar pattern that differed by only a few bands. These results indicate the spread of a genetically identical clone of S. enteritidis in humans and poultry in Thailand.     

Transthoracic ultrasound assessment of B-lines for identifying the increment of extravascular lung water in shock patients requiring fluid resuscitation

Introduction:

Several studies have shown that the number of B-lines was related to the amount of extravascular lung water (EVLW). In our study, we aimed to demonstrate the magnitude of the incremental B-lines in shock patients with positive net fluid balance and the association with gas exchange impairment.

Materials and Methods:

We performed trans-thoracic ultrasound at admission (T₀) and at follow-up period (T_FL) to demonstrate the change of B lines (ΔB-lines) after fluid therapy. We compared the total B-line score (TBS) at T₀ and T_FL and calculated the Pearson''s correlation coefficient between the ΔB-lines and PaO₂/FiO₂ ratio.

Results:

A total of 20 patients were analyzed. All patients had septic shock. Net fluid balance was + 2228.05 ± 1982.15 ml. The TBS at T₀ and T_FL were 36.6 ± 23.73 and 63.80 ± 29.25 (P < 0.01). The ΔB-lines along anterior axillary line (AAL) correlated to the ΔTBS (r = 0.90, P < 0.01). The ΔB-lines along AAL had inverse correlation to PaO₂/FiO₂ ratio (r = −0.704, P < 0.05). The increase of B-lines ≥ 10 was related to the decrease of PaO₂/FiO₂ ratio. The inter-observer reliability between two ultrasound readers was high (r = 0.92, P < 0.01).

Discussion:

The number of B-lines increased in shock patients with positive net fluid balance and correlated to impaired oxygenation. These data supported the benefit of ultrasound for assessing the EVLW.     

Orbital pseudotumor: clinical features and outcomes

To describe the clinical characteristics of orbital pseudotumor, a retrospective analysis was performed on patients with orbital pseudotumor at Siriraj Hospital for ten years. Forty-nine patients (24 males and 25 females; 62 eyes) with a mean age of 43.75 years were included (a mean follow-up of 25 months). Thirty-six patients (73.5%) had unilateral disease. The clinical features were proptosis (79.6%), ocular motor deficit (61.2%), pain (51%), lid swelling or lid mass (44.9%), ptosis (24.5%), and chemosis (18.4%). The most common presenting sign was proptosis (49%). All were treated with corticosteroids with clinical improvement in 40 (81.6%) patients. Ten (83.3%) of 12 patients with visual loss improved with mean recovery time of 10.3 days. Ocular motility recovered in 24 (80%) patients, occurring an average of 17.8 days after initiation of therapy. It is concluded that the clinical features of orbital pseudotumor are varied. Most patients were improved with corticosteroids treatment.     

Evaluation of antimycobacterial, antiplasmodial and cytotoxic activities of preussomerins isolated from the lichenicolous fungus Microsphaeropsis sp. BCC 3050

A new preussomerin isomer, 3'-O-demethylpreussomerin I, five known preussomerins E - I, and two known deoxypreussomerins, deoxypreussomerin A and bipendensin (palmarumycin C11), were isolated from a lichenicolous fungus Microsphaeropsis sp. BCC 3050. These structures were elucidated by spectroscopic methods, especially 1D- and 2D-NMR. The preussomerins were evaluated for their antimycobacterial and antiplasmodial activities as well as cytotoxicity against KB, BC-1 and vero cell lines.     

10-membered macrolides from the insect pathogenic fungus Cordyceps militaris BCC 2816

Three new 10-membered macrolides (1-3) have been isolated from the entomopathogenic fungus Cordyceps militaris BCC 2816, together with six known compounds, cepharosporolides C (4), E (5), and F (6), 2-carboxymethyl-4-(3'-hydroxybutyl)furan (7), cordycepin (8), and pyridine-2,6-dicarboxylic acid. The structures were determined by analysis of NMR data, and an X-ray analysis was performed to confirm the structure of 1. The antimalarial activity of 1-4 and 8 against Plasmodium falciparum K1 was evaluated.     

Identifying non-tuberculous mycobacterium lung diseases in acid-fast bacilli positive patients

We conducted a case-control study by comparing the clinical and radiographic features of acid-fast bacilli positive patients with pulmonary tuberculosis (PTB) to those with non-tuberculous mycobacterium (NTM) lung diseases diagnosed according to American Thoracic Society (ATS) criteria. The occurrence of NTM lung disease was associated with persistence in symptoms after the fifth month of treatment (p=0.018), middle lobe involvement (p<0.01), lower lobe involvement (p=0.004), multiple lobe involvement (p=0.001) and reticulo-nodular infiltration (p=0.041). On logistic regression analysis, persistence of symptoms after 5 months of treatment (p<0.001), middle lobe involvement (p<0.001) and lower lobe involvement (p<0.05) were significant predictors of NTM lung disease.These findings suggest physicians should consider NTM lung disease if there is involvement of the middle lobe or lower lobes on chest radiography or the persistence of symptoms at the fifth month of treatment.     

Recovery of Salmonella using a combination of selective enrichment media and antimicrobial resistance of isolates in meat in Thailand

From November 2004 to March 2005, 50 samples (chicken, pork and beef) of registered meat and non-registered meat were purchased from supermarkets and retail markets located in Bangkok, Thailand. Each sample was evaluated for Salmonella spp by a conventional method using combination of selective enrichment media (RV+MSRV) and compared with selective enrichment medium alone (DIASALM). Our study revealed the performance of RV+MSRV for the detection of Salmonella spp was significantly better than those of DIASALM alone since the recovery of Salmonella spp in both groups of meat was high using RV+MSRV, particularly in the registered meat. In addition, the recovery of serovars in registered meat was significantly higher than those in non-registered meat. Antimicrobial resistance of 62 Salmonella isolates in both groups of meat was determined for 10 antimicrobial drugs using the disk diffusion method. The results show that 100% of isolates from both groups were susceptible to amoxicillin/clavulanic acid, ciprofloxacin, cefotaxime and norfloxacin and 50-60% of isolates from both groups were resistant to tetracycline, streptomycin and ampicillin. Sixty percent of Salmonella isolates from meat showed multiresistance antimicrobial patterns.     

Mutational analysis of Plasmodium falciparum dihydrofolate reductase: the role of aspartate 54 and phenylalanine 223 on catalytic activity and antifolate binding

The catalytic activity and ability to confer resistance to antifolates of Plasmodium falciparum dihydrofolate reductase (pfDHFR) through single and double mutations at Asp-54 and Phe-223 were investigated. A single Asp54Glu (D54E) mutation in the pfDHFR domain greatly decreased the catalytic activity of the enzyme and affected both the K(m) values for the substrate dihydrofolate and the K(i) values for pyrimethamine, cycloguanil and WR99210. The Phe223Ser (F223S) single mutant had unperturbed kinetics but had very poor affinity with the first two antifolates. The ability to confer high resistance to the antifolates of F223S enzyme was, however, abolished in the D54E+F223S double mutant enzyme. When D54E mutation was present together with the A16V+S108T double mutation, the effects on the K(m) values for the substrate dihydrofolate and the binding affinity of antifolates were much more pronounced. The severely impaired kinetics and poor activity observed in A16V+S108T+D54E enzyme could, however, be restored when F223S was introduced, while the binding affinities to the antifolates remained poor. The experimental findings can be explained with a model for substrate and inhibitor binding. Our data not only indicate the importance of Asp-54 of pfDHFR in catalysis and inhibitor binding, but also provide evidence that infer the potentially crucial function of the C-terminal portion of pfDHFR domain.