Annarita D’Angelo

Bio: Annarita D’Angelo is an academic researcher. The author has contributed to research in topics: Mycoplasma mycoides & Humoral immunity. The author has an hindex of 2, co-authored 3 publications receiving 18 citations.

Prevalence of brucellosis in dairy cattle from the main dairy farming regions of Eritrea.

Abstract: In order to get a reliable estimate of brucellosis prevalence in Eritrean dairy cattle, a cross-sectional study was carried out in 2009. The survey considered the sub-population of dairy cattle reared in modern small- and medium-sized farms. Samples were screened with the Rose Bengal test (RBT) and positive cases were confirmed with the complement fixation test (CFT). A total of 2.77%(417/15 049; Credibility Interval CI: 2.52% – 3.05%) of the animals tested in this study were positive for antibodies to Brucellaspecies, with a variable and generally low distribution of positive animals at regional level. The highest seroprevalence was found in the Maekel region (5.15%; CI: 4.58% – 5.80%), followed by the Debub (1.99%; CI: 1.59% – 2.50%) and Gash-Barka (1.71%; CI: 1.34% – 2.20%) regions. Seroprevalence at sub-regional levels was also generally low, except for two sub-regions of Debub and the sub-region Haicota from the Gash-Barka region. Seroprevalence was high and more uniformly distributed in the Maekel region, namely in the Asmara, Berik and Serejeka sub-regions. Considering the overall low brucellosis prevalence in the country, as identified by the present study, a brucellosis eradication programme for dairy farms using a test-and-slaughter policy would be possible. However, to encourage the voluntary participation of farmers to the programme and to raise their awareness of the risks related to the disease for animals and humans, an extensive public awareness campaign should be carefully considered, as well as strict and mandatory dairy movement control.

Experimental infection of goats with an unusual strain of Mycoplasma mycoides subsp. capri isolated in Jordan: comparison of different diagnostic methods.

Abstract: Ten goats were experimentally infected with a Mycoplasma identified by biomolecular methods as Mycoplasma mycoides subsp. capri, strain Irbid which was isolated from goats in an outbreak of contagious agalactia in north Jordan and defined as 'unusual', due to its serological characteristics. Two groups of goats infected by the endotracheal route and by aerosol, respectively, were placed in contact with a third group of naive animals. Six weeks after infection, some animals from both the infected and contact groups presented fever and nasal discharge, followed by severe respiratory signs and polyarthritis. Organs were taken from animals that died during the trial or those that were sacrificed at the end of the trial. The results of microbiological isolation and immunohistochemical tests conducted on the organs were compared after a description of the clinical picture and anatomopathological and histopathological signs.

Effects of immune serum on macrophage cell cultures infected with Mycoplasma mycoides subsp. mycoides small colony: morphological analysis by scanning electron microscopy.

Abstract: Macrophages are pivotal cells of the immune system and play a key role in the host defence mechanism against pathogens. To date, the importance of macrophages and the role of humoral response in eliciting macrophage activity against Mycoplasma mycoides subsp. mycoides small colony (Mmm-SC), the causative agent of contagious bovine pleuropneumonia (CBPP), have only been marginally elucidated or are almost unknown. The present study was undertaken to investigate the changes in surface morphology of macrophages after in vitro infection with Mmm-SC in the presence of bovine immune serum. Morphological analysis was performed on macrophage cultures at 6 h post infection using the three-dimensional vision of scanning electron microscopy. Non-infected macrophages in the presence of negative or immune serum and macro phages infected with Mmm-SC in the absence of serum showed only minor cell surface changes. In contrast, clear surface modifications, broad veils, fine philopodia highlighting cell activation and small aggregates of mycoplasma closely attached to the macrophage membrane, were observed in infected macrophage cultures in the presence of immune serum. Our results suggest that specific humoral response to Mmm-SC may contribute and support phagocytic activity of macrophages.

An essay towards solving a problem in the doctrine of chances. [Facsimil]

Abstract: Problem Given the number of times in which an unknown event has happened and failed: Required the chance that the probability of its happening in a single trial lies somewhere between any two degrees of probability that can be named. SECTION 1 Definition 1. Several events are inconsistent, when if one of them happens, none of the rest can. 2. Two events are contrary when one, or other of them must; and both together cannot happen. 3. An event is said to fail, when it cannot happen; or, which comes to the same thing, when its contrary has happened. 4. An event is said to be determined when it has either happened or failed. 5. The probability of any event is the ratio between the value at which an expectation depending on the happening of the event ought to be computed, and the value of the thing expected upon it’s 2 happening.

Isolation and Characterization of Mycoplasma mycoides Subspecies capri from Milk of Natural Goat Mastitis Cases

Abstract: Association of Mycoplasma mycoides subspecies capri (Mmc) with natural goat mastitis has been studied earlier largely by detecting the Mmc DNA using molecular methods. However, report on detection of cultivable Mmc isolates from natural goat-mastitis milk is still very rare. In this study, Mmc was isolated from milk samples (n = 171) of goats with or without clinical signs of mastitis. Mmc isolates were further characterized by biochemical and species-specific PCR methods. Intra species strain variation was also studied by 16S amplified rDNA restriction analysis (16S ARDRA). The study recovered a total of 6 Mmc isolates (3.5%). Three types of intraspecies variants among the recovered Mmc isolates were found by 16S ARDRA. The study concluded that Mmc may be an etiological agent of mycoplasmal mastitis in Indian goat herds.

Epidemiological study of bovine brucellosis in three senatorial zones of Bauchi State, Nigeria.

Abstract: Aim: To determine the seroepidemiological patterns of bovine brucellosis in three senatorial zones of Bauchi State, Nigeria. Materials and Methods: Blood samples were aseptically collected from the anterior jugular vein of 336 slaughtered cattle, between September 2013 and March 2014 in three senatorial zones of Bauchi State, Nigeria. The sera obtained were screened for brucellosis using rose Bengal plate test (RBPT) and serum agglutination test (SAT) in parallel. The data generated was subjected to Chi-square and Fishers exact test analysis to establish whether there is a relationship between the breeds, sex, and location of the animals sampled. Results: Of the 336 cattle screened, 18 (5.4%) and 13 (3.9%) were positive by RBPT and SAT, respectively. There was no statistically significant association (p>0.05) between the sex, age, and location of cattle with seropositivity of brucellosis in the state. It was concluded that brucellosis is prevalent in Bauchi State. Further study is recommended in other abattoirs and herds of cattle in Bauchi State for confirmation of the status of the disease among cattle slaughtered in the state. Conclusion: A high seroprevalence of brucellosis among the cattle in Bauchi state indicates that the disease is endemic and cattle are one of the animals that perpetuate and sustain the disease.

Mycoplasma agalactiae: The Sole Cause of Classical Contagious Agalactia?

Abstract: Contagious agalactia (CA) is suspected when small ruminants show all or several of the following clinical signs: mastitis, arthritis, keratoconjunctivitis and occasionally abortion. It is confirmed following mycoplasma isolation or detection. The historical and major cause is Mycoplasma agalactiae which was first isolated from sheep in 1923. Over the last thirty years, three other mycoplasmas (Mycoplasma mycoides subsp. capri, Mycoplasma capricolum subsp. capricolum and Mycoplasma putrefaciens) have been added to the etiology of CA because they can occasionally cause clinically similar outcomes though nearly always in goats. However, only M. agalactiae is subject to animal disease regulations nationally and internationally. Consequently, it makes little sense to list mycoplasmas other than M. agalactiae as causes of the OIE-listed CA when they are not officially reported by the veterinary authorities and unlikely to be so in the future. Indeed, encouraging countries just to report M. agalactiae may bring about a better understanding of the importance of CA. In conclusion, we recommend that CA should only be diagnosed and confirmed when M. agalactiae is detected either by isolation or molecular methods, and that the other three mycoplasmas be removed from the OIE Manual of Diagnostic Tests and Vaccines in Terrestrial Animals and associated sources.