A 28-year-old lady suffering from systemic lupus erythomatosus (SLE) with diffuse proliferative glomerulonephritis (DPGN) and who was on oral cyclophosphamide and prednisolone presented with left lower limb 'cellulitis'. The 'cellulitis' of the left lower limb failed to respond to usual antibiotics which prompted evaluation of the clinical diagnosis. The diagnosis is made based on the presence of granulomas, multinucleated giant cells and acid fast bacilli on the skin biopsy.
In vitro deoxyribonucleic acid (DNA) amplification by the polymerase chain reaction (PCR) followed by hybridization with oligonucleotide probes were used to study ras gene mutations in acute myeloid leukemia (AML). The DNA of 30 AML patients at presentation of the disease at the University of Malaya Hospital, Kuala Lumpur were screened for ras gene mutations in codons 12, 13 and 61 of the N-ras, K-ras and H-ras genes. Four patients (13.3%) had ras gene mutations. They were all below their early thirties in age. Of the four patients with ras gene mutations, three were M3 and one was M4 according to the French American British (FAB) classification of AML.
The HLA-DQ alpha genotype and allele frequencies in 130 Malays, 125 Chinese, and 137 Indians in the Malaysian population were determined using a commercial HLA-DQ alpha DNA amplification and typing kit which distinguishes 6 alleles (DQA1.1, DQA1.2, DQA1.3, DQA2, DQA3, and DQA4) and 21 possible genotypes at this locus. All 21 genotypes were encountered in the Malay and Indian samples, but DQA1.1,DQA1.3 and DQA2,DQA2 genotypes were absent in the Chinese sample. In all three ethnic groups, the numbers observed for the various DQ alpha genotypes were in accordance with those expected from Hardy-Weinberg equilibrium. The allele frequencies observed in these three groups were significantly different to allow them to be distinguished as distinct populations. For the Malays, Chinese, and Indians, heterozygosity values at this locus were 0.77, 0.77, and 0.83, respectively, and values of the power of discrimination were 0.91, 0.90, and 0.94, respectively. These population data will enable the HLA-DQ alpha locus to be used as a marker in forensic identity testing in Malaysia.
Fifteen independent E. coli strains of avian, bovine and porcine origin in Peninsular Malaysia were tested for antibiotic resistance and conjugative R plasmids. Eight (53%) isolates were found to be antibiotic resistant. Among them, 37.5% were mono-resistant and 62.5% were resistant to three or more antibiotics, i.e., multi-resistant. All of them were resistant to Tc and sensitive to Gm and Nx. Three of the eight antibiotic resistant strains were able to transfer all or part of their resistance to an E. coli K12 recipient by conjugation. The transfer frequencies of Km, Sm and Tc resistance of the three donors varied between 4.5 X 10(-8) to 6.8 X 10(-7). Analysis of the plasmid profiles of all the three donors and their respective transconjugants after agarose gel electrophoresis provided conclusive evidence that the transferable resistance traits were plasmid-mediated.
Four of the five veterinary E. coli strains, which were unable to transfer their antibiotic resistance by conjugation, were found to harbour plasmids. Evidence from transformation, agarose gel electrophoresis and curing experiments showed that in strains KE-3, KE-4 and KE-14 a nonconjugative R plasmid carried the gene for resistance to tetracycline. The plasmids in KE-9 were cryptic.
A clinical isolate of Proteus sp., resistant to ampicillin, carbenicillin, cephaloridine, chloramphenicol, cotrimoxazole, gentamicin,
kanamycin and tetracycline, was examined for the presence of conjugative R plasmids. Results from conjugation, agarose gel
electrophoresis and transformation experiments showed that it harboured a large self-transmissible R plasmid which coded for all
the resistance traits.
Twenty-five strains of enterobacteria, isolated from man in Peninsular Malaysia and consisting of seven Enterobacter spp., five Escherichia coli, five Salmonella spp., four Klebsiella spp., two Shigella spp., one Proteus sp. and and one Providencia sp., were tested for antibiotic resistance and conjugative R plasmids. They were all sensitive to nalidixic acid and resistant to at least three antibiotics. The number of resistances ranged from 3 to 11 antibiotics, including cefoperazone and sisomicin (two) newly released antibiotics), in addition to common drugs of current use. Of the 25 isolates, 19 (76%) conjugally transferred, at varied frequencies, at least two resistance determinants. Results from equilibrium density gradient centrifugation, agarose gel electrophoresis and transformation experiments provided proof that the transferable resistances were plasmid-mediated. Restriction endonuclease cleavage patterns showed that the plasmids from Proteus strain K005 and Providencia strain K001 may be identical.