From January 1983 to December 1992 a total of 20,874 salmonella were serotyped in the Bacteriology Division IMR, which showed an increase of 100% compared to the previous ten-years. There were 97 serotypes which belonged to 22 Kauffmann-white groups. Twenty two serotypes hitherto were seen in this study period. S. typhi was the commonest serotype isolated. Overall there was a rise in the isolation of non-typhoidal salmonella particularly S. enteritidis which increased by 760% and S. blockley which increased by 720%. However there is a drop in the isolation of S typhimurium by 223% and S. paratyphi B by 319%.
Publication year=1996-1997
During the 5-year (1981-5) surveillance period, 2322 salmonella isolations were recorded from animals and other non-human sources in Peninsular Malaysia. This was an increase of 356% over the preceding 5-year period. The 83 serotypes isolated were recovered from 41 sources. Of these 34 were new serotypes bringing the total number of serotypes isolated from non-human sources to date up 97. Food animals and edible animal products accounted for 92.2% of the total isolations, with cattle and beef accounting for 70% of the total. Salmonella dublin was the most frequently isolated serotype, whereas S. typhimurium had the widest zoological distribution. More than 80% of the non-human salmonella serotypes have also been reported in man in this country.
Salmonella weltevreden has been found to be one of the commonest Salmonella serotypes isolated from diverse sources in India and has also been isolated in a number of other countries. A phage typing scheme was developed for this serotype using a set of six typing phages. These phages had been selected out of 146 phage strains isolated and purified from stool samples of man, laboratory animals and other animals, sewage and surface water sources, and the lytic mutants of temperate phages form S. weltevreden. The phage typing scheme was applied systematically to type the 946 strains from India isolated during 1958-1974 and 148 strains originating from Australia, Burma, England, Gan Island, Holland, Hong Kong, Malaysia, New Zealand, Papua New Guinea, The Philippines, Thailand, The United States and Vietnam during 1953-1971. The scheme was particularly studied to evaluate its utility in mapping the epidemiologically related strains from various sources. The S. weltevreden strains could be classified into ten phage types. Phage types 2 and 7 were found exclusively amongst Indian strains, type 6 from Vietnam and type 8 from Burma, Thailand and Vietnam. Phage types were found to be stable and consistent with the independent epidemiological data available.
Salmonella sp is a significant cause of morbidity and mortality. Although commonly infecting the gastrointestinal system, other presentations are not unheard of. Salmonella is an unlikely and an unusual cause of genital tract infection. We describe a woman with suspected pelvic inflammatory disease eventually confirmed as Salmonella O C2 infection.
The results of serotyping of 10 953 salmonella isolates from humans over a 10-year period, 1973-82 at the Bacteriology Division, Institute for Medical Research, Malaysia are presented. A total of 104 serotypes from 22 'O' groups were encountered; 95 isolates were considered untypable. The three most predominant serotypes, namely Salmonella typhi, S. typhimurium and S. weltevreden together accounted for 54.1% of all isolates whilst the 25 most frequent serotypes accounted for 93.6% of the total. Whilst the commoner serotypes occurred regularly throughout the study period, the rarer ones tended to appear only in one year, when they might be associated with an outbreak, and never again. The pattern of serotypes, though quite similar to the one seen in neighbouring Singapore, is different from those experienced in other places such as Hong Kong, Jakarta, Bangladesh and Manchester.
A total of 860 Salmonella isolations were made in Peninsular Malaysia from 15 animal species (domestic and wild), eggs, molluscs, flies, and animal feed. The isolations were distributed among 31 serotypes in eight groups. The most common serotype isolated was Salmonella pullorum, followed by S. choleraesuis and S. infantis. S. typhimurium had the widest zoological distribution. The importance of controlling animal salmonellosis is emphasized.
A total of 43 Salmonella enterica isolates belonging to different serovars (Salmonella Albany, Salmonella Agona, Salmonella Corvallis, Salmonella Stanley, Salmonella Typhimurium, Salmonella Mikawasima, and Salmonella Bovismorbificans) were isolated from catfish (Clarias gariepinus) and tilapia (Tilapia mossambica) obtained from nine wet markets and eight ponds in Penang, Malaysia. Thirteen, 19, and 11 isolates were isolated from 9 of 32 catfish, 14 of 32 tilapia, and 11 of 44 water samples, respectively. Fish reared in ponds were fed chicken offal, spoiled eggs, and commercial fish feed. The genetic relatedness of these Salmonella isolates was determined by random amplified polymorphic DNA PCR (RAPD-PCR) using primer OPC2, repetitive extragenic palindromic PCR (REP-PCR), and pulsed-field gel electrophoresis (PFGE). Composite analysis of the RAPD-PCR, REP-PCR, and PFGE results showed that the Salmonella serovars could be differentiated into six clusters and 15 singletons. RAPD-PCR differentiated the Salmonella isolates into 11 clusters and 10 singletons, while REP-PCR differentiated them into 4 clusters and 1 singleton. PFGE differentiated the Salmonella isolates into seven clusters and seven singletons. The close genetic relationship of Salmonella isolates from catfish or tilapia obtained from different ponds, irrespective of the type of feed given, may be caused by several factors, such as the quality of the water, density of fish, and size of ponds.
Salmonella infections remain a major public health problem in developing countries. The occurrence of infections caused by antimicrobial-resistant Salmonella has been on the rise complicating the available therapeutic options. The study aimed to determine the antibiograms and genotypes of prevalent Salmonella serotypes.
House shrews (Suncus murinus) and rats (Rattus rattus diardii), trapped during a survey period from July 1978 to December 1979 and thereafter on a random basis, from residences within and outside the Veterinary Research Institute, Ipoh, Malaysia campus, were bacteriologically examined for the presence of salmonellae. Of the 55 shrews and 8 rats examined, 39 (71%) shrews and 2 (25%) rats were found positive. There were 46 Salmonella isolates which included 5 dual infections. These were serotyped as S. weltevreden, S. bareilly, S. stanley, S. augustenborg, S. hvittingfoss, S. emek, S. paratyphi B, S. ohio and S. matopeni in order of frequency of isolation. The significance of these findings especially with regard to salmonellosis in man and animals is discussed.
The suitability of a PCR procedure using a pair of primers targeting the hilA gene was evaluated as a means of detecting Salmonella species. A total of 33 Salmonella strains from 27 serovars and 15 non-Salmonella strains from eight different genera were included. PCR with all the Salmonella strains produced a 784 bp DNA fragment that was absent from all the non-Salmonella strains tested. The detection limit of the PCR was 100 pg with genomic DNA and 3 x 10(4) c.f.u. ml(-1) with serial dilutions of bacterial culture. An enrichment-PCR method was further developed to test the sensitivity of the hilA primers for the detection of Salmonella in faecal samples spiked with different concentrations of Salmonella choleraesuis subsp. choleraesuis serovar Typhimurium. The method described allowed the detection of Salmonella Typhimurium in faecal samples at a concentration of 3 x 10(2) c.f.u. ml(-1). In conclusion, the hilA primers are specific for Salmonella species and the PCR method presented may be suitable for the detection of Salmonella in faeces.
The importance of Campylobacter and Salmonella as foodborne pathogens is well recognised globally. A recent work in Penang found ducks in commercial farms were infected with these organisms. The aim of the study was to detect the presence of Campylobacter and Salmonella in ducks and Salmonella in duck eggs in farms in a small part of Selangor. Cloacal swabs were obtained from 75 ducks and 30 duck eggs from three farms. The isolation and identification of Campylobacter and Salmonella were done using conventional methods. Twelve percent of Campylobacter and 16.0% of Salmonella were isolated from the ducks sampled. Salmonella was absent on and in eggs. Campylobacter isolates consisted of 22% Campylobacter jejuni and the remaining was Campylobacter coli. Three Salmonella serovars identified were Salmonella Agona, S. Braenderup and S. Corvallis. The presence of Campylobacter and Salmonella in ducks may cause contamination of the meat during processing and handling which can constitute public health hazard. Moreover, the farm workers may be exposed to the organisms through contact with the infected animals.
Ten strains of Salmonella weltevreden isolated from poultry sources were examined and found to contain plasmid DNA ranging in size from 1.8 to 68.5 MD. All isolates were susceptible to carbenicillin, cephalothin, ceftriazone, gentamicin, kanamycin and nalidixic acid, but resistance to bacitracin (100%), penicillin G (100%), rifampicin (100%), sulphamethoxazole (100%), cefuroxime (80%) and tetracycline (60%) was recorded. The 55 MD plasmid of strain SW5 determined resistance to penicillin G and tetracycline, which was transmissible to the E. coli K12 recipient at a frequency of 3.52 x 10(-5) transconjugants per input donor cell. The results of arbitrarily primed polymerase chain reaction (AP-PCR), using two 10-mer oligonucleotides and PCR-ribotyping to differentiate between the ten strains of S. weltevreden were compared. The strains were separated into ten different genome types by AP-PCR but were indistinguishable by PCR-ribotyping. These results suggest that poultry may constitute a reservoir for disseminating antibiotic resistance and that AP-PCR may be a valuable tool for epidemiological studies.
Salmonella enterica serovar Paratyphi A is a causative agent of paratyphoid fever. The clinical syndrome caused by paratyphoid fever overlaps with other febrile illnesses and cannot be distinguished from typhoid fever. Conventional methods used for diagnosis are time consuming, costly, and labor-intensive. We evaluated the specificity, sensitivity, and application of a multiplex polymerase chain reaction (PCR) previously developed by the method (Ou, H.Y., Teh, C.S.J., Thong, K.L., et al., J. Mol. Diagn., 9, 624-630, 2007) using 6 S. Paratyphi A, 22 S. Typhi, and 85 other Salmonella serovars as well as 36 non-Salmonella strains. The detection limit of the multiplex PCR was 4 x 10(4) cfu ml(-1). In a blind test of the other 50 strains, this multiplex PCR correctly identified the only S. Paratyphi A in the panel of strains. The sensitivity of this PCR using spiked blood and stool samples was 1 x 10(5) cfu ml(-1) and 2 x 10(5) cfu ml(-1), respectively, but increased to 1 x 10(4) cfu ml(-1) and 2 x 10(3) cfu ml(-1) after 5-h enrichment. We believe that this multiplex PCR is a promising technique for the specific and sensitive detection of S. Paratyphi A in clinical, environmental, and food samples.
Non-typhoidal Salmonella (NTS) bacteremia is a significant cause of morbidity and mortality worldwide. It is considered to be an emerging and neglected tropical disease in Africa. We studied this in two tertiary hospitals-Al Farwaniya and Al Amiri-in Kuwait, a subtropical country, from April 2013-May 2016. NTS bacteremia was present in 30 of 53,860 (0.75%) and 31 of 290,36 (1.33%) blood cultures in the two hospitals respectively. In Al Farwaniya hospital, one-third of the patients were from some tropical developing countries of Asia. About 66% of all patients (40/61) had diarrhea, and of these, 65% had the corresponding blood serovar isolated from stool culture. A few patients had Salmonella cultured from urine. Patients were either young or old. Most of the patients had co-morbidities affecting the immune system. Two patients each died in both hospitals. The number of different serovars cultured in each hospital was 13, and most infections were due to S. Enteritidis (all sequence type [ST]) 11) and S. Typhimurium (all ST19) except in a subgroup of expatriate patients from tropical developing countries in Al Farwaniya hospital. About a quarter of the isolates were multidrug-resistant. Most patients were treated with a cephalosporin with or without other antibiotics. S. Enteritidis and S. Typhimurium isolates were typed by pulsed field-gel electrophoresis (PFGE) and a selected number of isolates were whole-genome sequenced. Up to four different clades were present by PFGE in either species. Whole-genome sequenced isolates showed antibiotic-resistance genes that showed phenotypic correlation, and in some cases, phenotypes showed absence of specific genes. Whole-genome sequenced isolates showed presence of genes that contributed to blood-stream infection. Phylogeny by core genome analysis showed a close relationship with S. Typhimurium and S. Enteritidis from other parts of the world. The uniqueness of our study included the finding of a low prevalence of infection, mortality and multidrug-resistance, a relatively high prevalence of gastrointestinal infection in patients, and the characterization of selected isolates of S. Typhimurium and S. Enteritidis serovars by whole-genome sequencing that shed light on phylogeny, virulence and resistance. Similarities with studies from developing countries especially Africa included infection in patients with co-morbidities affecting the immune system, predominance of S. Typhimurium and S. Enteritidis serovars and presence of drug-resistance in isolates.
PCR-restriction fragment length polymorphism (PCR-RFLP) and PCR-single-strand conformation polymorphism (PCR-SSCP) analyses were carried out on the 1.6-kb groEL gene from 41 strains of 10 different Salmonella serovars. Three HaeIII RFLP profiles were recognized, but no discrimination between the serovars could be achieved by this technique. However, PCR-SSCP analysis of the groEL genes of various Salmonella serovars produced 14 SSCP profiles, indicating the potential of this technique to differentiate different Salmonella serovars (interserovar differentiation). Moreover, PCR-SSCP could differentiate strains within a subset of serovars (intraserovar discrimination), as three SSCP profiles were produced for the 11 Salmonella enterica serovar Enteritidis strains, and two SSCP profiles were generated for the 7 S. enterica serovar Infantis and five S. enterica serovar Newport strains. PCR-SSCP has the potential to complement classical typing methods such as serotyping and phage typing for the typing of Salmonella serovars due to its rapidity, simplicity, and typeability.
Non-typhoidal Salmonella (NTS) is increasingly recognized as an important pathogen associated with bacteraemia especially in immunosuppressed patients. However, there is limited data specifically describing the clinical characteristics and outcome amongst the immunosuppressed patients.
The genetic diversity and antimicrobial resistance rates of clinical Salmonella isolates (2007-2008) at the University of Malaya Medical Centre, Kuala Lumpur, were investigated and the genetic diversity of the isolates was determined by pulsed-field gel electrophoresis (PFGE) and repetitive extragenic palindromic (REP)-PCR. XbaI-PFGE analysis generated 57 profiles (Dice coefficient, F=0.08-1.00), whereas REP-PCR using the REP primer generated only 35 (F=0.34-1.00). PFGE was therefore the more discriminative and reproducible method for assessing the genetic diversity of salmonellae. The antibiograms of 78 Salmonella isolates were assessed against 19 antimicrobials using the disk diffusion method. Twenty serotypes were identified, with the most common being S. Enteritidis (18%) followed by S. Typhimurium (14%), S. Paratyphi B var Java (9%), S. Weltevreden (9%), and S. Corvallis (9%). A total of 38 resistant profiles were defined, with 53.8% of the isolates being resistant to three or more antimicrobials. The highest resistance rates were observed for cephalothin (55.1%), tetracycline (47.4%), and nalidixic acid (35.9%). The presence of multidrug-resistant Salmonella strains is a cause for concern as it may limit the treatment of severe salmonellosis. One multidrug-resistant S. Enteritidis strain was a putative extended-spectrum beta-lactamase producer, based on a double disk diffusion analysis, and was resistant to ceftriaxone (MIC>32 microg/mL). The data generated by this study will contribute towards epidemiological monitoring and investigations of Salmonella infections in Malaysia.