Restriction fragment length polymorphism study of Mycobacterium tuberculosis in Thailand using IS6110 as probe.

SETTING: Three referral hospitals in central Thailand. OBJECTIVE: To determine the population structure of Mycobacterium tuberculosis isolated from the referral hospitals. DESIGN: Study of 211 isolates of the bacteria received from the hospitals in central Thailand by Southern hybridization, with IS6110 probe and other probes when indicated. RESULTS: In 43 isolates only one copy of IS6110 was observed. These could be further differentiated by DR- and PGRS-specific probes. Two large groups of isolates with similar hybridization patterns were identified. The Beijing family, comprising 80 isolates, was previously reported to be commonly found in China, Mongolia, Thailand and Korea. The Nonthaburi group, comprising 29 isolates, were local strains. The age, sex and HIV status of the patients did not significantly correlate with the chance of being infected by isolates of any particular hybridization pattern. However, clustered isolates were found more commonly among the members of both the Beijing family and the Nonthaburi group. CONCLUSION: Southern hybridization with IS6110 was found to be useful in studying the epidemiology of tuberculosis in Thailand. The existence of the Beijing family was confirmed. The unusually wide spread of the Beijing family in several countries in Asia merits further investigation.

Histochemical stainings, biological cultures and therapeutic responses of granulomatous lymphadenitis in Ramathibodi Hospital-prospective study of 57 cases.

The study was designed to delineate the etiology of granulomatous lymphadenitis which is one of the most common lesions encountered in our routine surgical pathology practice. Fifty-seven lymph nodes diagnosed histopathologically as granulomatous lymphadenitis were cultured and stained by special histochemical stains for tuberculosis, fungus, anaerobic and aerobic bacteria. M.tuberculosis was isolated in 60-70 per cent of lesions. The remaining 30-40 per cent of the lesions failed to demonstrate any infectious agent but most of the available follow-up cases showed satisfactory response to antituberculous drugs. Ziehl-Neelsen's stain showed very low sensitivity but excellent specificity and is still recommended for use to differentiate from other infectious agents in the areas where infectious agents are prevalent.

Human pythiosis associated with thalassemia hemoglobinopathy syndrome.

Pythium infection (pythiosis) in humans has not previously been described, even in areas endemic for animal pythiosis. We report five patients with a unique presentation of fungal arteritis. The medium- to large-sized arteries were involved, and in some cases this involvement led to gangrene of the limbs, aneurysm formation, and ultimately fatal arterial leakage. All five patients were farmers. All patients, with the possible exception of one who had hemoglobin typing performed after receiving a blood transfusion, had thalassemia hemoglobinopathy syndrome. Fungal isolation was difficult. Amphotericin B treatment seemed to be ineffective. Radical surgical removal of infected tissues and oral administration of a saturated solution of potassium iodide are proposed therapy. In the tropics, where Pythium is ubiquitous, one should actively look for this fungal infection in patients with unexplained arterial occlusion, especially in the case of patients with thalassemia hemoglobinopathy syndrome.

Spontaneous Vibrio vulnificus peritonitis and primary sepsis in two patients with alcoholic cirrhosis.

Two patients with alcoholic cirrhosis were seen on two separate occasions for fever, swollen legs, petechial hemorrhage, purpura, and cutaneous bullae. One patient ate oysters 2 days before the onset of illness. Vibrio vulnificus, a lactose-positive halophilic vibrio, was isolated from the ascitic and cutaneous fluid in both cases, and from the blood in one of the two cases. Both isolated strains were sensitive to the antibiotics given to the patients from the beginning; however, both patients died, one from septicemic shock and the other from massive esophageal variceal hemorrhage. Autopsies in both patients revealed alcoholic cirrhosis, hemorrhagic necrosis of the terminal ileum, intraalveolar hemorrhage, petechial hemorrhage in the peritoneum, and nonspecific acute inflammation of the dermis with vasculitis. Physicians should consider V. vulnificus in the differential diagnosis of cirrhotic patients with sepsis, primary skin lesions, and spontaneous bacterial peritonitis with or without history of recent oyster ingestion.

Simple screening method for isolation of penicillin acylase-producing bacteria.

A new screening method for bacteria capable of producing penicillin acylase is described. The method is based on the use of Serratia marcescens sensitive to 6-aminopenicillanic acid but comparatively resistant to benzylpenicillin. It is simple, quite specific, and requires no special equipment. It can also be used to screen for phenoxymethylpenicillin acylase activity. We also suggest an acidimetric method for rapid detection of cloned genes in genetic engineering studies of penicillin acylase.