Demographic data on Salmonella enteritidis infection in Thailand, 1990-1995.

The data for the comprehensive analysis of Salmonella enteritidis infection was based on the information recorded in the request form submitted for Salmonella typing and the results of serotyping at the WHO National Salmonella and Shigella Center, Department of Medical Sciences, Ministry of Public Health, Thailand during 1990-1995. Fifty-one cases of S. enteritidis (SE) infection were confirmed in 1990. The morbidity being markedly increased each year from 1991 to 1995, with 105, 307, 471, 659 and 877 cases being identified, respectively. Among the isolates of Salmonella spp, SE was the most common serotype during 1993-1995. The cases were mostly predominant in Bangkok and then in southern, northeastern, central and northern regions, respectively. The morbidity rates per 100,000 population per year of SE infection in 1990-1995 were 0.09, 0.18, 0.53, 0.8, 1.11 and 1.47, respectively. Analysis of the infection rate by sex and age demonstrated that the incidence in males was higher than in females. Adult patients were more frequently found than adolescent patients. The organism was found in feces, blood, pus, urine, cerebrospinal fluid and sputum, accounting for 41.7, 35.8, 5.5, 2.5, 1.7 and 0.4%, respectively. The average extraintestinal isolation index was 0.52.

Incidence of salmonellae in duck eggs in Thailand.

Detection of salmonellae was performed on egg shells and egg contents of duck eggs. Five hundred and sixty-four tested samples were came from 1,128 eggs, 2 eggs in each sample. Eggs were collected from retail markets in Bangkok, Chon Buri, Chachoengsao, Lop Buri, Ang Thong and Nakhon Ratchasima provinces during January through June 1992. The percentage of salmonellae contamination on the egg shells only, egg contents only and both shells and contents were 12.4%, 11% and 0.2%, respectively. Twenty three serotypes were identified from the 133 salmonellae isolates. The common serotypes found from duck eggs were Salmonella typhimurium, S. cerro, S. tennessee, S. amsterdam, S. agona and S. infantis accounting for 5.5%, 4.1%, 2.8%, 2.1%, 1.4% and 1.1%, respectively.

Detection of salmonellae in hen eggs in Thailand.

Two thousand four hundred and ninety eggs were collected from retail markets in 6 provinces and from laying hen farms in 3 provinces. Eggs were pooled in groups of 3 to obtain 830 samples for testing. Isolation of salmonellae was made from both egg shell and egg contents. Eggs from retail markets were contaminated with salmonellae on egg shells (13.2%) and in egg contents (3.9%). Three (0.4%) samples yield positive both on egg shells and in egg contents. Of the 86 samples from laying hen farms, salmonellae were found on egg shells and in egg contents, 3.5% and 1.2%, respectively. From the 134 strains tested, twenty-four serotypes were confirmed. Salmonella cerro, S. amsterdam and S. typhimurium were predominantly encountered, 4.8%, 4.3% and 1.4%, respectively. Only two samples were contaminated with S. enteritidis, one each from open market and laying hen farm, one on egg shells and the other in egg content respectively.

The occurrence of salmonellae in bean sprouts in Thailand.

Detection of Salmonella spp. in 344 samples of bean sprouts was attempted by pre-enriched in buffered peptone water (BPW) or lactose broth (LB) at 37 degrees C, followed by selective enrichments, selenite cystein broth (SCB) and Rappaport medium (RV) at 43 degrees C. Four selective media, bismuth sulphite agar (BSA), brilliant green agar (BGA), Salmonella-Shigella agar (SSA) and MacConkey agar (MA) were used for isolation. Salmonellae were isolated from 30 (8.7%) samples. They were serotypes lexington (56.7%), orion (16.7%), senftenberg (16.7%), tennessee (3.3%), poona (3.3%) and weltevreden (3.3%). Pre-enrichment in LB, followed by enrichment in SCB and streaking on to BSA gave the highest recoveries. Fifteen of 30 strains isolated were sensitive to all 14 antibiotics tested. Seven strains were resistant to one, and a strains showed multiple resistance to 2-4 antimicrobial agents.

Characteristics of Pasteurella multocida isolated from humans, swine and poultry in Thailand.

Pasteurella multocida is a pathogen of animals and humans. Most of the patients have been associated with animals but many cases had not contacted them. The failure to diagnose P. multocida infections is mostly due to misidentification on gram stained smears and inadequate laboratory identification techniques. In order to compile detailed characteristics of the organism we studied the physical and biochemical properties of 70 isolates of P. multocida - 17 human, 23 swine and 30 poultry. All isolates produced catalase, oxydase, indol, nitrate reduction and ornithine decarboxylase. They failed to produce urease, gelatinase, methyl red, acetoin and could not grow on MacConkey agar, SS-agar, in nutrient broth with 0% or 6% NaCl. With respect to fermentable sugars, all isolates consistantly produced acid from glucose, mannitol and mannose. None of the cultures fermented lactose, maltose and dulcitol. Marked variations in the patterns of fermentation of arabinose and xylose were found. The characteristics tested are important to facilitate identification of P. multocida but could not be used to differentiate the host of the bacterium.