Mycoplasma infection in Malaysian children: laboratory investigation and antimicrobial therapy.

Background: Mycoplasma pneumonia (M. pneumoniae) is an important causative agent of childhood infection with variable clinical presentations. The objective of the study was to evaluate the laboratory investigation and antimicrobial therapy of M. pneumoniae infection in children admitted to paediatric ward. Materials & Methods: A total of 111 children, of which 59 (53.2%) boys and 52 (46.8%) girls, with median age of 2 years (inter quartile range 1-6 years) with suspected M. pneumoniae infection were tested for IgM by enzyme-linked immunosorbent assay (ELISA). The children were classified as seropositive and seronegative. Results: Of the 111 children, 45 (40.5%) had serological evidence of M. pneumoniae infection and the remaining 66 (59.5%) were seronegative. There was significant association (p < 0.001) between age and serology response. Seropositive children were more likely to be older (median age 5.0 [interquartile range 2- 7] years, p < 0.001). Children with M. pneumoniae infection were less likely to have cough (p = 0.023) in which 55 (65.5%) patients having cough were seronegative. There was no significant association between laboratory findings of full blood count and serology. Conclusion: In addition to clinical and laboratory features, other factors like age group and absence of cough might be helpful in predicting M. pneumoniae infection.

Prevalence of biofilm-producing Staphylococcus epidermidis in the healthy skin of individuals in Tamil Nadu, India.

Purpose: Staphylococcus epidermidis is a major commensal bacteria. Various strains of S. epidermidis are capable of forming biofilms by attaching to several surfaces. Biofilm-forming ability of this organism is found to be associated with many hospital-acquired infections and can even impair wound healing. S. epidermidis strains producing polysaccharide-biofilms possess the intercellular adhesion (ica) operon while strains forming the protein adhesion-mediated biofilms possess the accumulation associated protein (aap) gene. We screened for biofilm-forming S. epidermidis in the skin of healthy individuals in Tamil Nadu in order to determine the risk of acquiring S. epidermidis infections in hospital settings. Materials and Methods: Skin swabs were taken from seventy two subjects residing in Chennai with healthy skin who showed no visible signs of skin lesions or allergies. S. epidermidis was isolated from 58 samples out of the 72 collected. The presence of ica operon in S. epidermidis isolates was determined by PCR and biofilm production was examined using quantitative tissue culture plate assay. Results: Majority of the samples (47/72; 65.3%) showed pure S. epidermidis growth, (14/72; 19.4%) showed pure Staphylococcus aureus growth and the remainder (11/72; 15.3%) showed mixed growth. Biofilm-forming S. epidermidis were found in the majority of samples (53/58; 91.4%) and ica operon was detected in 19 samples out of 58 (32.8%) which is a significantly higher percentage when compared to other studies conducted at different parts of the globe ( P = 0.0003). Conclusion: We inferred that ica operon and biofilm-forming S. epidermidis are common in the healthy skin of individuals in Tamil Nadu. Measures have to be taken to reduce the risk of hospital-acquired S. epidermidis infections.

Mitogenic response of rat lung and tracheal epithelial cells in monolayer primary cultures—Modulation of TNF-α expression.

Epithelial cells isolated from rat lung and trachea were grown on monolayers and their response to a number of hormones and growth factors were studied. Maximum proliferative response in serum containing media was observed when insulin, cholera toxin and cortisol were present together. However, these additives when present independently showed a marginal response. The synergism, due to these factors in promoting growth was seen very early in culture (day 4) as shown by thymidine labelling studies, On examining the indices of early mitogenesis, such as the expression of c-myc, our data suggests that these factors stimulate the expression of c-myc within 4 h. With respect to expression of TNF-α mRNA, this study suggests a possible modulation of TNF-α expression in response to these mitogens that stimulate proliferation maximally. Whether this expression of TNF-α by these epithelial cells is due to a maximal proliferative stimulus and/or is an early step in the cascade of intracellular signalling events is to be investigated in detail.