Volume 2, Emitir 1 (2018)

Artigo de Pesquisa

Behavior of an Emetic Bacillus cereus Strain in Rice Food

Elise N’Guessan, Laurence Delbrassinne and Jacques Mahillon

Subject description: This article deals with the possible competitiveness of emetic B. cereus against nonemetics, likely to confer a development advantage to the first mentioned. The goal of this study was to evaluate the behavior of an emetic strain with respect to other B. cereus contaminants.

Method: A rifampicin-resistant mutant of the emetic strain k5975c was grown in Luria-Bertani. Broth overnight at 30°C, then inoculated in cooked rice or in naturally contaminated rice and incubated for 24 h at 23°C and 30°C. The emetic toxin and its toxicity were detected using the boar sperm motility inhibition bioassay and the liquid chromatography-ion trap mass spectrometry (LC-MS).

Results: With an inoculum level of ca. 6 log CFU g-1, the emetic strain showed unhampered growth in rice contaminated by other B. cereus at both incubation temperatures, although it did not inhibit the growth of B. cereus contaminants. When the inoculum level of the emetic strain was reduced to ca. 3 log CFU g-1, its development was unaffected when the background of resident B. cereus was below 5 log CFU g-1. However, above this level of resident B. cereus strains, the emetic strain developed modestly at both 23°C and 30°C.

The presence of the emetic toxin activity was detected when the final concentration of the emetic strain reached ca. 5.6 log CFU g-1 and above this level.

Conclusion: Our study mimicked naturally occurring emetic food poisonings. It relates to the reported severe forms of rice food poisoning caused by emetic B. cereus.

Artigo de Pesquisa

An Emerging Zoonosis of Bovine Tuberculosis-A Neglected Zoonotic Disease (NZD) in Work-Related Occupational Groups in Pakistan

Asad Ullah, Umar Sadique Khattak, Sultan Ayaz and Muhammad Subhan Qureshi

Background: Tuberculosis (TB) is potentially serious infectious disease caused by the bacterium Mycobacterium tuberculosis (MTB). Bovine tuberculosis (BTB) is found one of the neglected zoonotic disease (NZD) caused by Mycobacterium bovis has an economic importance and public health significance and appear as a life threatening infection at the human-animal-ecosystem interface in low-resource settings and less developed countries across the world. Employees in different categories of work may be deliberately or unintentionally exposed to biological agents. Lack of information leads to spread of an infection. Globally, insufficient information is available on human TB caused by Mycobacterium bovis in emerging states.

Aims: To specify the incidence of pulmonary tuberculosis due to M. bovis in specific work-related occupational groups such as livestock farm workers, abattoir workers, butchers, veterinarians and veterinary assistants and also to document their awareness, level of knowledge and practices concerning bovine tuberculosis.

Materials and Methods: A study was conducted on livestock farm workers, abattoir workers, butchers, veterinarians and veterinary assistants. Data was obtained on socio-demographic conditions, awareness, level of knowledge and practices about tuberculosis. The sputum samples were also collected from those individuals who were suffering from cough and finally confirmed by PCR. Data was finally analysed statistically using chi squared test.

Results: A total of 390 sputum samples belonging to 800 study participants were collected which consisted of 100 TB patients admitted in different human hospitals in the study area, 200 livestock farm workers, 174 abattoir workers, 294 butchers, 10 veterinarians and 22 veterinary assistants. As a result, 2 out of 100 TB patients (2/100), 3 out of 200 livestock farm workers (3/200) and 3 out of 23 abattoir workers (3/23) were found positive for the presence of M. bovis through PCR technique. A significant association (p<0.05) was found between livestock farm workers and abattoir workers with the prevalence of zoonotic tuberculosis.

The level of knowledge and awareness of livestock farmers, abattoir workers, butchers and veterinary assistants concerning the zoonotic spread of BTB and the signs & symptoms of human TB was very miserable. Majority of the manual workers were unaware about the principles of biosafety and biosecurity and did not use personal protective equipment (PPE) and were considered high risk occupational groups of gaining zoonotic TB.

Conclusions: Bovine tuberculosis is a major public health problem in especially work-related occupational groups in district Peshawar, the capital city of Khyber Pakhthunkhwa, Pakistan. The surveillance, prevention and control programs of this NZD in the province Khyber Pakhthunkhwa, Pakistan is necessary because of the continual unrestricted movement of the animals which might result in an increased spread of BTB to humans.

Artigo de revisão

Mechanisms Efflux Pumps of Acinetobacter Baumannii (MDR): Increasing Resistance to Antibiotics

Francis T Dongmo Temgoua, Wu Liang and Chen Sheng-Xia

Acinetobacter Baumannii has greatly increased its degree of resistance to become multidrug resistant (MDR) over the past 30 years and is on the red line of the most widely replicated bacteria according to World Health Organization (WHO). The efflux pumps are the main cause for the increasing antibiotic resistance of A.baumannii originated from nosocomial infection. The progressive resistance of A.baumannii even on the recent drugs (tigecycline and fosfomycin) reduces to very effective antibiotic scale. With attention focused on MDR and pan-drugresistant (PDR) in A.baumannii multiple works on efflux pumps chemical inhibitor (NMP, PAβN, omeprazole, verapamil, reserpine, CCCP) are still in progress. Certain inhibitors from plants (Biricodar and timcodar, Falvone, Mahonia, Dalea versicolor, Lycopus europaeus, and Rosmarinus officinalis) have the capability to have such compounds according to their very significant synergistic effect with antibiotics. In this review we focused on the growth of antibiotic resistance to explain the mechanism of efflux pumps into these different super families and a comprehensive understanding of the extrusion, regulation and physiology role of drug efflux pumps in the essential development of anti-resistivity drugs. We recapitulated the evolution of the work carried out in these fields during the last years and in the course of elaboration, with the aim of increasing the chances of decreasing bacterial resistivity to antibiotics.

Artigo de Pesquisa

Identification and Determination of Minimum Inhibitory Concentrations of Plant Extracts having Antimicrobial Activity as Potential Alternative Therapeutics to Treat Aeromonas hydrophila Infections

Grace Ramena*, Yathish Ramena and Nitin Challa

Aeromonas hydrophila causes infections in wide range of organisms including humans. It causes serious and life threatening lethal infections in humans. Motile aeromonas septicemia causes huge economic loss to fish farmers. Antibiotic use and abuse is a huge problem that is environmentally lethal, leading to antibiotic resistance and difficulty in treating bacterial infections. There is always a need to find new and safe alternatives to antibiotics to deal with bacterial infections. In this study we have evaluated 11 herb and spice extracts for their antimicrobial activity against Aeromonas hydrophila and compared their activity with commercially available antibiotic to treat this disease. We found that clove and cinnamon methanol extracts had significantly higher antibacterial effect against A. hydrophila when compared to oxytetracycline and other extracts. Both the extracts have higher activity at the lowest concentration tested (5 mg) and can potentially serve as alternative therapeutics to A. hydrophila infections in humans as well as fish.

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