Investigation of methicillin-resistant Staphylococcus aureus among clinical isolates from humans and animals by culture methods and multiplex PCR

Background

Staphylococcus aureus is responsible for large numbers of hospital-related and community-acquired infections. In this study, we investigated the presence of S. aureus and methicillin-resistant S. aureus (MRSA) in 100 samples from animals (55 cattle, 36 dogs, and 9 cats) and 150 samples from hospitalized human patients. The samples were collected from healthy and diseased animals and from diseased humans and included milk, wound swab, pus, exudates, nasal swab and diabetic ulcer. Initially, S. aureus was isolated and identified by colony morphology, Gram staining, and biochemical tests (catalase and coagulase tests). The S. aureus-positive samples were examined by polymerase chain reaction (PCR) to determine their MRSA status.

Results

Of the 100 animal samples, 29 were positive for S. aureus. Four samples (13.8%) from dogs were MRSA-positive, but samples from cattle and cats were MRSA-negative. Of the 150 human samples we collected, 64 were S. aureus-positive and, of these, 34 (53.1%) were MRSA-positive. Most (28%) of the MRSA samples were isolated from surgical wound swabs, followed by the pus from skin infections (11%), exudates from diabetic ulcers (6%), exudates from burns (4%), and aural swabs (3%). By contrast, a low MRSA detection rate (n = 4) was seen in the non-human isolates, where all MRSA bacteria were isolated from nasal swabs from dogs. The antimicrobials susceptibility testing results showed that S. aureus isolates with mecA genes showed resistance to penicillin (100%), oxacillin (100%), erythromycin (73.5%), ciprofloxacin (70.6%), and gentamicin (67.7%). The lowest resistance was found against ceftazidime, and no vancomycin-resistant isolates were obtained.

Conclusions

We detected S. aureus and MRSA in both human and canine specimens. Isolates were found to be resistant to some of the antimicrobials available locally. MRSA carriage in humans and animals appears to be a great threat to effective antimicrobials treatment. The prudent use of antimicrobials will reduce the antimicrobial resistance. Our findings will help to find the most appropriate treatment and to reduce antimicrobial resistance in the future by implementing prudent use of antimicrobials. Further studies are required to better understand the epidemiology of MRSA human–animal inter-species transmission in Bangladesh.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1611-0) contains supplementary material, which is available to authorized users.

Role of courtyard counselling meeting in improving household food safety knowledge and practices in Munshiganj district of Bangladesh

Unsafe food is linked to the deaths of an estimated two million people annually. Food containing harmful agents is responsible for more than 200 diseases ranging from diarrhoea to cancers. A one-sample pilot intervention study was conducted to evaluate the role of courtyard counselling meetings as the means of intervention for improving food safety knowledge and practices among household food handlers in a district of Bangladesh. The study was conducted in three phases: a baseline survey, the intervention and an end-line survey between April and November 2015 where 194 food handlers took part. Data were collected through observations and face-to-face interviews. The mean age of the respondents was 38.8 (±12.4) years, all of whom were females. Hand washing before eating, and washing utensils with soap were significantly improved at the end-line in comparison to the baseline (57% vs. 40% and 83% vs. 69%, respectively). Hand washing with soap was increased by 4%. The mean score of food handling practices was significantly increased after the intervention (20.5 vs. 22.1; P<0.001). However, hand washing after use of toilet was unchanged after the intervention (75% vs.76%). Knowledge about safe food and the necessity of thorough cooking were significantly increased after the intervention (88% from 64% and 34% from 21%, respectively). Mean scores of knowledge and practice on food safety were significantly increased by 1.9 and 1.6, respectively after the one month intervention. Thus this food safety education in rural communities should be scaled up and, indeed, strengthened using the courtyard counselling meetings in Bangladesh.

The value of intercondylar notch visualization of the posteromedial and posterolateral compartments during knee arthroscopy

The intercondylar notch views allow for visualization of the posteromedial and posterolateral compartments of the knee without the use of accessory portals. The purpose of this study was to prospectively evaluate whether these views are useful either diagnostically or therapeutically in the performance of knee arthroscopy. Two surgeons at one institution performed 150 consecutive knee arthroscopies. After arthroscopic examination of the knee using standard portals, a diagnosis and treatment decisions were made. Thereafter, visualization of the posteromedial and posterolateral compartments through the intercondylar notch was undertaken. Each view was performed initially with a 30 degrees arthroscope and 3 questions were asked: (1) Did the view change the diagnosis or add additional information? (2) Did it change the surgical treatment? (3) Was it useful during performance of the procedure? The 70 degrees arthroscope was then used and the same three questions were addressed. In 20.6% of the cases, the intercondylar notch views made a diagnostic and/or therapeutic difference, and the surgical procedure was changed in 11.3% based solely on this information. The views were 3 times as likely to make a difference in anterior cruciate ligament (ACL) reconstructions when compared with arthroscopy without ACL reconstruction (P <.01). The 70 degrees arthroscope added nominal additional information. There were no significant complications. We advocate visualization of the posteromedial and posterolateral compartments through the intercondylar notch as a valuable part of routine knee arthroscopy.

The fracture table as a distraction mode in ankle arthroscopy

Adequate distraction can be obtained in ankle arthroscopy by placing a Steinmann pin transversely in the calcaneus and using the fracture table in a hip or tibial nailing mode. A sterile traction bow is attached to the calcaneal pin and then to the traction crank apparatus of the fracture table. Gross traction is first applied through the leg in the usual manner and then fine traction tension may be increased or decreased intraoperatively through the traction crank. This method of using the fracture table is easy to perform and is familiar to the orthopaedist, as it is used in intramedullary nailing procedures. The primary advantage is that it allows for excellent exposure while avoiding the morbidity associated with a distraction pin through the distal tibia.