Rat Meat Research Articles

A lab-on-a-chip-based multiplex platform to detect potential fraud of introducing pig, dog, cat, rat and monkey meat into the food chain

Food forgery has posed considerable risk to public health, religious rituals, personal budget and wildlife. Pig, dog, cat, rat and monkey meat are restricted in most religions, but their sporadic adulteration are rampant. Market controllers need a low-cost but reliable technique to track and trace suspected species in the food chain. Considering the need, here we documented a lab-on-a-chip-based multiplex polymerase chain reaction (PCR) assay for the authentication of five non-halal meat species in foods. Using species-specific primers, 172, 163, 141, 129 and 108-bp sites of mitochondrial ND5, ATPase 6 and cytochrome b genes were amplified to detect cat, dog, pig, monkey and rat species under complex matrices. Species-specificity was authenticated against 20 different species with the potential to be used in food. The targets were stable under extreme sterilisation (121°C at 45 psi for 2.5 h) which severely degrades DNA. The assay was optimised under the backgrounds of various commercial meat products and validated for the analysis of meatballs, burgers and frankfurters, which are popular fast food items across the globe. The assay was tested to detect 0.1% suspected meats under commercial backgrounds of marketed foods. Instead of simplex PCR which detects only one species at a time, such a multiplex platform can reduce cost by at least fivefolds by detecting five different species in a single assay platform.

Leptospira Exposure and Waste Pickers: A Case-Control Seroprevalence Study in Durango, Mexico.

BackgroundInfection with Leptospira may occur by contact with Leptospira-infected animals. Waste pickers are in contact with rodents and dogs while picking in the garbage. Whether waste pickers are at risk for Leptospira infection is largely unknown. This study was aimed to determine the association of Leptospira IgG seroprevalence with the occupation of waste picking, and to determine the epidemiological characteristics of the waste pickers with Leptospira exposure.MethodsThrough a case-control study, we determined the seroprevalence of anti-Leptospira IgG antibodies in 90 waste pickers and 90 age- and gender-matched control subjects in Durango City, Mexico using an enzyme immunoassay. Data were analyzed by bivariate and multivariate analyses.ResultsThe prevalence of anti-Leptospira IgG antibodies was similar in waste pickers (4/90: 4.4%) to that in control subjects (5/90: 5.6%) (P = 1.00). Bivariate analysis showed that Leptospira exposure in waste pickers was associated with increasing age (P = 0.009), no education (P = 0.008), and consumption of rat meat (P = 0.04). However, these associations were no longer found by multivariate analysis. Leptospira exposure in waste pickers was not associated with health status, duration in the activity, wearing hand gloves and facemasks, history of injuries with sharp material of the garbage, or contact with animals or soil.ConclusionsThis is the first study about Leptospira exposure in waste pickers. Results suggest that waste pickers are not at increasing risk for Leptospira exposure in Durango City, Mexico. Further research with a larger sample size to elucidate the association of Leptospira exposure with waste picking activity is needed.

The employment of FTIR spectroscopy in combination with chemometrics for analysis of rat meat in meatball formulation

For Indonesian community, meatball is one of the favorite meat food products. In order to gain economical benefits, the substitution of beef meat with rat meat can happen due to the different prices between rat meat and beef. In this present research, the feasibility of FTIR spectroscopy in combination with multivariate calibration of partial least square (PLS) was used for the quantitative analysis of rat meat in the binary mixture of beef in meatball formulation. Meanwhile, the chemometrics of principal component analysis (PCA) was used for the classification between rat meat and beef meatballs. Some frequency regions in mid infrared region were optimized, and finally, the frequency region of 750–1000cm−1 was selected during PLS and PCA modeling. For quantitative analysis, the relationship between actual values (x-axis) and FTIR predicted values (y-axis) of rat meat is described by the equation of y=0.9417x+2.8410 with coefficient of determination (R2) of 0.993, and root mean square error of calibration (RMSEC) of 1.79%. Furthermore, PCA was successfully used for the classification of rat meat meatball and beef meatball.

Feasibility study for the detection of Trichinella spiralis in a murine model using mid-Fourier transform infrared spectroscopy (MID-FTIR) with attenuated total reflectance (ATR) and soft independent modelling of class analogies (SIMCA)

Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance (ATR) and soft independent modelling by class analogies (SIMCA) was used to assess the feasibility of detecting Trichinella spiralis in a murine model. The selected FTIR wavenumber range was 1700–900cm−1 and the first derivative of the spectra was subjected to SIMCA analysis. The SIMCA model developed for rat meat spiked with T. spiralis larvae was successfully apply to classify non-infected from infected rat meat with a limit of detection of 3 larvae/10g rat meat and no false positives with 99% confidence limit. To avoid false positives arising from the presence of other parasites, another chemometric model was developed to demonstrate the capacity of the model to discriminate between Ascaris suum, Taenia solium and T. spiralis. Results confirmed that this method could correctly distinguish these parasites. Additional studies are needed to prove the effectiveness of this technique for other types of muscle meats, including those relevant to human consumption.

The Use of Cytochrome b Gene as a Specific Marker of the Rat Meat (Rattus norvegicus) on Meat and Meat Products

Falsification of the origin of livestock meat and its processed with rat meat is a problem that must be overcome to ensure food safety. One way that is often used to detect forgeries by using cytochrome b gene as a marker. The purpose of this study was to create a specific primer derived from cytochrome b sequences in rat (Rattus norvegicus) as the DNA marker to detect any contamination of rat meat on fresh livestock meat and its processed meat products. Meatballs were made from beef meat with the addition of rat 1%-25%, and the meatballs were obtained from traditional markets. DNA extraction was conducted from seven species (goat, chicken, cattle, sheep, pig, horse, and rat) by using phenol-chloroform. The highest success rate in detecting the presence of rat meat in a mixture of beef meatballs at concentration of 15% was 100%. The specific fragment of cytochrome b gene in R. norvegicus has no similarity with the cytochrome b gene from six other species, so it can be used as molecular markers to detect the presence of rat meat contamination in the processed of meat products. Amplified fragment length for goats, chickens, cattle, sheep, pigs, horses, and rats 157, 227, 274, 331, 398, 439 and 603 bp respectively. The amplification of cytochrome b gene in seven species of animals with different fragment length indicated the specificity of cytochrome b gene sequences among species.

FT-MIR and Raman spectroscopy coupled to multivariate analysis for the detection of clenbuterol in murine model

A fast and simple screening method for the determination of clenbuterol at the ppb level in a murine model was demonstrated by Mid Infrared (MIR) and Raman spectroscopy in conjunction with multivariate analysis. In order to build the calibration models to quantify clenbuterol in rat meat, mixtures of rat meat and clenbuterol were prepared in a range of 5-10,000 ppb. Partial Least Square (PLS) analysis was used to build the calibration model. The results shown that Mid Infrared and Raman spectroscopy were efficient, but Mid Infrared (R(2) = 0.966 and SEC = 0.27) were superior to Raman (R(2) = 0.914 and SEC = 1.167). The SIMCA model developed showed 100% classification rate of rat meat samples with or without clenbuterol. The results were confirmed with contaminated meat samples from animals treated with clenbuterol. Chemometric models represent an attractive option for meat quality screening without sample pretreatments which can identify veterinary medicinal products at the ppb level.

Endo- and ectoparasites of the Philippine rice field rat, <i>Rattus tanezumi</i> Temminck, on PhilRice farms

The Philippine rice field rat, Rattus tanezumi Temminck, is one of the principal pre- and postharvest pests of rice and other agricultural crops. This species usually thrives in lowland and upland rice fields but can also be found in or near places of human habitation. They damage agricultural crops and also serve as reservoir hosts for diseases of certain human and domestic animals caused by helminths, protozoans, and microbes. Many endoparasites infecting the different viscera of R. tanezumi belong to taxonomic groups Nematoda (roundworms), Cestoda (tapeworms), and Trematoda (flukes). The more important ones are those that are transmissible to humans. In contrast, there have been few reports on the ectoparasites that infest these rats. These are the mites, ticks, and fleas, some of which may serve as vectors of microbial infections to humans and domestic animals. Rattus tanezumi is an alternative meat source for the rural folk. Rat meat is a favorite accompaniment to alcoholic beverages during drinking sprees. Unknowingly, some zoonotic infections can be transmitted to humans through improperly cooked rat meat and viscera, accidental wound contamination with rat urine, or rat bites during handling and precooking preparations

Salmonellae in the African Great Cane Rat (Thryonomys swinderianus)

Because of its large size, the African great cane rat (Thryonomys swinderianus) is valued for food and has become a popular meat in western Africa. A survey was conducted to determine the occurrence of salmonellae in cane rats. Ten strains of Salmonella sp. were isolated from eight of 25 (32%) cane rats. Salmonella ajiobo was isolated from the spleen and intestines of three cane rats; S. agama was obtained from the spleen, liver and intestines of three animals; and S. poona was isolated from the spleen and liver of two cane rats. The occurrence of salmonellae in T. swinderianus is a potential public health hazard. Humans may become exposed to infection by consumption of inadequately cooked infected cane rat meat, or by eating vegetables, sugar cane and fruits contaminated with excretions of carrier cane rats. Incidents of human salmonellosis attributable to cane rat meat have not yet been reported; however, all three serotypes isolated from the cane rats have also been isolated from stools of patients suffering from gastroenteritis in Nigeria.

Relationship between the presence of 44 megadalton plasmid and calcium dependency or autoagglutination to serotype O3 strains of Yersinia enterocolitica.

A total of 207 strains of Yersinia enterocolitica serotype O3 isolated from human, pig, dog, cat, rat and pork meat during the period between 1972 and 1984 were examined for the 44-megadalton plamid DNA, calcium dependency and autoagglutination. Strains positive for the plasmid, calcium dependency and autoagglutination were counted and found to be 164(79.2%), 152(73.4%) and 149(72.0%) respectively. All the plasmodia harboring strains were either calcium dependent or positive for the autoagglutination. All the strains which lacked the plasmid were calcium independent and negative for the autoagglutination except four strains (1.9%) that were positive for the autoagglutination. Despite different sources of Y. enterocolitica, all the plasmid positive strains harbored a single plasmid of 44-megadalton. These plasmids had identical restriction endonuclease digestion patterns, and the number of digestion fragements by BamHI, EcoRI and HindIII were 9, 10 and 13, respectively. Based on these results, it is suggested that the presence of the 44-megadalton plasmid Y. enterocolitica serotype O3 strains is closely related to calcium dependency and autoagglutination and that this plasmid may be inherent to serotype O3.

Feeding of Buteo lagopus pallidus

The author obtained a Rough-legged Buzzard, Buteo lagopus pallidus, shot alive 7 December 1954 at Hanno-gawa, Kahoku-machi, Momou-gun, Miyagi Prefecture. Its feeding behavior for various foods, fish meat, rat, mink, bird, frog, sanke, and animal meat, etc., are reported. The bird was first fed with fish but later disliked it and frog or snake, though they were finally eaten. It took 1325g. of food at a time and 2kg. a day. Fatty meat was not its taste. After it ate a poisoned rat, given by mistake, it dared a 8-days fast and after this it used to throw animal's viscera. Showed inherent skill in catching a thrown food, drank water almost every morning, and took small pebbles when sprinkled in the cage. Reported also about its pellet, which is digorged 24-60 hours (usually 24-36 hours for feathers) after the food was taken.