Methicillin-resistant commensal staphylococci in healthy dogs as a potential zoonotic reservoir for community-acquired antibiotic resistance

Beta-lactam-resistant staphylococci evolved due to widespread nosocomial antibiotic use during the twentieth century, but the last decade has seen the emergence of genotypically distinct resistant bacteria outside hospitals, such as community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). This changing epidemiology suggests that mechanisms other than direct antibiotic selection could be involved in the spread of bacterial resistance. Here we report a 17% prevalence of methicillin-resistant Staphylococcus intermedius (MRSI)–a markedly higher rate than the 0–2% reported in some other series–in a random sample of nasal swabs from healthy pet dogs in Hong Kong. In contrast, MRSA was not detected. Since the mecA mobile genetic element responsible for methicillin resistance has been shown by others to be horizontally transmissible between dogs and humans, our findings suggest that the high prevalence of this resistance vector in companion species is a legitimate concern for public health, and raise the important possibility that pet-acquired methicillin-resistant staphylococci (PA-MRS) could play a role in zoonotic mecA gene spread.     

The development of vaccines against SARS corona virus in mice and SCID-PBL/hu mice

We have investigated to develop novel vaccines against SARS CoV using cDNA constructs encoding the structural antigen; spike protein (S), membrane protein (M), envelope protein (E), or nucleocapsid (N) protein, derived from SARS CoV. Mice vaccinated with SARS-N or -M DNA using pcDNA 3.1(+) plasmid vector showed T cell immune responses (CTL induction and proliferation) against N or M protein, respectively. CTL responses were also detected to SARS DNA-transfected type II alveolar epithelial cells (T7 cell clone), which are thought to be initial target cells for SARS virus infection in human. To determine whether these DNA vaccines could induce T cell immune responses in humans as well as in mice, SCID-PBL/hu mice was immunized with these DNA vaccines. As expected, virus-specific CTL responses and T cell proliferation were induced from human T cells. SARS-N and SARS-M DNA vaccines and SCID-PBL/hu mouse model will be important in the development of protective vaccines.     

Evaluation and validation of an enzyme-linked immunosorbent assay and an immunochromatographic test for serological diagnosis of severe acute respiratory syndrome

A newly developed severe acute respiratory syndrome (SARS)-specific enzyme-linked immunosorbent assay (ELISA) was further validated to confirm cutoff values and evaluate its diagnostic performance with clinical samples. In parallel, an immunochromatographic test was also evaluated. A total of 227 clinical serum specimens collected from SARS patients were used in the study, together with 385 samples from healthy donors. By use of an immunofluorescent (IF) test as the "gold standard", both the ELISA and the immunochromatographic test were able to detect immunoglobulin G antibodies to SARS not only from late-convalescent-stage samples (>21 days from the onset of clinical symptoms), as previously established, but also from early-acute-phase samples (1 to 10 days from onset). The ELISA, using an optical density (OD) of 0.25 as its cutoff value, produced the best sensitivity while maintaining high specificity. It detected SARS-specific antibodies in 58, 70, 75, and 95%, respectively, of the four groups of samples collected from patients 1 to 10 days, 11 to 20 days, 21 to 30 days, and more than 30 days after the onset of clinical symptoms. Similarly, the immunochromatographic test detected SARS-specific antibodies in 55, 68, 81, and 79% of the four groups, respectively. The overall specificities for the ELISA and the rapid test were 99.5 and 97.7%, respectively. Although the positive correlation observed between the ELISA OD values and the IF titers was moderate (r = 0.6915; P < 0.001), the detection rates of both the ELISA and the rapid test were found well in agreement with the IF titers.     

Reaching for the bottle of pesticide--a cry for help. Self-inflicted poisonings in Sri Lanka

This long-term study in Sri Lanka explored the complexities behind self-inflicted pesticide poisonings by 166 Sri Lankans. Using or threatening to use pesticides for self-harm has become a response to stressful events and a powerful message towards a specific individual, or to the outside world in general, conveying misgiving, anger, sadness, hopelessness, frustration, or simply a way to manipulate a situation to one's own advantage. The effects of alcohol misuse are especially important in understanding self-harm at the community level in terms of the impact they have on the domestic environment. Also, issues around "love affairs," arranged marriages and domestic physical, sexual or psychological abuse in the domestic environment are referred to by many self-harmers or their relatives as a reason for ingesting poison. Clearly, easy access to lethal pesticides by impulsive individuals often living under economically or psychosocially stressful conditions, combined with insufficient treatment facilities and limited outreach programs, can be a deadly blend. A strategy aimed at reducing the availability of the most toxic pesticides and improving case management should be implemented, as it is likely to reduce death from pesticides although unlikely to impact on the number of episodes. Support to families plagued by domestic violence and male alcohol misuse is essential to improve the quality of life for the most vulnerable and to reduce the number of self-harm episodes in the long-term.     

Endocrine abnormalities in morbid obesity

Recognizing the hormonal changes that accompany morbid obesity may prevent inappropriate investigations and treatments as well as provide rational approaches to reducing the morbidity and mortality of this disorder. The secondary nature of some of these metabolic changes can be demonstrated by overfeeding nonobese subjects. The crucial role of achieving adequate weight loss is also emphasized by the reversal of most of the hormonal abnormalities following successful weight loss.