Pathological changes and bacteriological assessments in the urinary tract of pregnant goats experimentally infected with Brucella melitensis

Phagocytosis and intracellular killing of Pasteurella multocida B:2 by macrophages: A comparative study between buffalo and cattle

Background and Aim:

Pasteurella multocida B:2 is the causative agent of hemorrhagic septicemia (HS) in buffalo and cattle. Buffaloes are known to be more susceptible to HS than cattle, but the reason for this remains unknown. This study aimed to compare the in vitro efficiency with which buffalo and cattle macrophages can kill P. multocida B:2.

Materials and Methods:

Monocyte-derived macrophages of buffalo and cattle were used in this study. They were exposed to 1×10⁶ colony-forming unit/mL of live P. multocida B:2 before the cells were harvested at 0, 30, 60, and 120 min post-exposure and viewed under a fluorescence microscope to count viable and non-viable macrophages and the macrophages with phagocytosing P. multocida B:2 cells. The phagocytosis, intracellular bacterial killing, and macrophage death rates were calculated and compared between the two species and sampling points.

Results:

In general, the rates of phagocytosis, intracellular killing, and macrophage death increased with time of exposure for both animal species. No significant (p>0.05) differences were noted between the phagocytosis rates by the macrophages of buffalo and cattle throughout the experiment. However, the rates of intracellular killing were significantly (p<0.05) higher in cattle macrophages at 30 min and 120 min post-exposure than those of buffalo. The death rates of buffalo macrophages were significantly (p<0.05) higher than those of cattle at 60 min and 120 min post-exposure.

Conclusion

With higher bacteria killing ability and lower macrophage death, cattle appeared to be more efficient at handling P. multocida B:2 infection than buffalo.

Antigenic distribution, pathological changes, antibody response and serological detection in non-pregnant goats following experimental infection by Brucella melitensis

This study describes the pathological changes, antibody response, isolation and distribution patterns following exposure of non-pregnant goats to live Brucella melitensis. Eighteen healthy adult female goats were divided into two equal groups. Group 1 was infected via conjunctival sac with 10⁹  cfu/ml of B. melitensis, while Group 2 was similarly exposed to sterile PBS. Serum and swabs from the eyes and vagina were collected at 5-day intervals. On days 15, 30 and 75 post-infection, 3 goats from each group were killed before the conjunctiva, ovary, oviduct, uterine horn, uterine body and vagina, the submandibular, prescapular and supramammary lymph nodes, the mammary gland, liver, spleen, urinary bladder and synovial membranes were collected for bacterial isolation and pathological study. Exposure of non-pregnant goats to B. melitensis did not produce clinical signs and gross lesions but produced mild necrosis and inflammation in the lymph nodes, the organs of reproductive tract, the mammary gland and urinary bladder. In general, microscopic lesions were most severe in the D75 goats, followed by D30 and D15 goats. Brucella melitensis was most frequent and significantly (p < .05) isolated from the D30 (64.4 ± 25.2%) and least from D15 goats (39.3 ± 26.0%) goats. The organs that were most frequently isolated were the uterus, followed by the mammary gland, supramammary lymph node and urinary bladder. Earliest isolation from the ocular swabs was on day 5, while the vaginal swabs were on day 20 post-infection. The antibody response showed first significant (p < .05) increase on day 15 and reached peak on day 45 post-infection, corresponding with the first detection of sero-converter goats by the RBPT at 15 days and by the CFT at 40 days post-infection. In conclusion, infected non-pregnant goats shed B. melitensis through the vagina by day 20. The sero-positive goats were detectable by RBPT after 15 days but by CFT after 40 days. Since both serological tests detected positive goats at different time period of infection, paired-serum samplings might reduce this discrepancy.

Urological infections in the developing world: an increasing problem in developed countries

PURPOSE

Infectious diseases that often follow geographical distribution patterns are increasingly crossing such boundaries, aided by human travel and commerce. These pose a new challenge to physicians who are required to diagnose previously unseen conditions and address drug-resistant organisms. We review some such common infections.

METHODS

A literature review was performed for six common urological infections and a narrative review based on recent publications on these infections was compiled.

RESULTS

In Urology, some infections that are now crossing geographical boundaries include Brucellosis, Schistosomiasis, Tuberculosis, Filariasis, Hydatidosis and emphysematous pyelonephritis. Brucellosis, a zoonotic infection, is common in the Mediterranean areas, Asia, South America and Africa. Infection can involve all parts of the genitourinary tract. Schistosomiasis, a parasitic disease, is particularly common in Sub-Saharan Africa and may have bacterial superinfection. Voiding symptoms are common and bladder carcinoma may develop. Tuberculosis affects almost every organ in the body and in the male genital system, often presents with abscesses, nodules, ulcers and infertility that is difficult to manage. Filariasis is caused by two species of worms and is transmitted through a bite from a mosquito carrying larvae of the worm. It causes lymphatic obstruction leading to scrotal edema, hydrocoele to elephantiasis of scrotum. Emphysematous pyelonephritis is a life-threatening suppurative necrotizing infection of the renal parenchyma. While not being geographically limited, it is more common in developing areas with poor health care access. Genitourinary hydatidosis is a rare disease that is associated mainly with renal involvement in the genitourinary tract. Large cysts with destruction of renal parenchyma may be found.

CONCLUSIONS

Although uncommon, these urological infections are associated with significant morbidity and mortality and awareness in all healthcare settings is now an essential requirement.