Gabriel Martins

Leptospirosis as the most frequent infectious disease impairing productivity in small ruminants in Rio de Janeiro, Brazil.

Despite the importance of small ruminants breeding in developing countries, milk/meat productivity remains unsatisfactory. Infectious diseases, such as leptospirosis, brucellosis, and small ruminant lentiviruses (SRLVs), contribute to this scenario. The objective of the present study was to determine the role of each of these diseases in the productivity of small ruminants breeding in Rio de Janeiro, Brazil. In goats, 343 samples were tested for leptospirosis, 560 for Brucella abortus, and 506 for caprine arthritis-encephalitis (CAE), whereas in sheep, 308 samples were tested for leptospirosis, 319 for B. abortus, 374 for Brucella ovis, and 278 for Maedi-Visna (MV). Regarding leptospirosis, 25.9% of goats and 47.4% sheep were seroreactive, with serovar Hardjo the most prevalent in both species. Anti-B. abortus agglutinins were found in 0.7% of all samples, exclusively in goats. In relation to SRLVs, 8.6% of goats and 3.2% of sheep samples were positive for CAE and MV, respectively. Leptospirosis was the major infectious problem in the small ruminants sampled and may contribute to impaired productivity of these animals.

The role of horses in the transmission of leptospirosis in an urban tropical area.

The objective of this study was to demonstrate the presence of leptospires in equine urine, as evidence for a potential role of horses in transmission of this organism. Thoroughbred horses (aged 2-5 years, n = 276) from Rio de Janeiro, Brazil, were studied. After a severe storm, the premises of the animals remained flooded for 72 h. Blood samples for serology were collected on days 20 and 35 (day of storm = day 0). On day 20, 132 (47·8%) horses were seroreactive (titre ≥200) and, of these, 23 (31·0%) had increased antibody titres on day 35. Furthermore, 34 urine samples (for PCR and culture) were collected from seroreactive horses on day 35. Copenhageni was the most frequent serovar (88·8% of reactive titres). Although none of the urine samples were culture positive, 12 (35·2%) were PCR positive. This is apparently the first report of evidence of leptospires in urban horses. Furthermore, we suggest that these animals can play a role in the transmission of leptospirosis in urban areas.

The role of leptospirosis in reproductive disorders in horses

Leptospirosis is a zoonotic disease of global importance and has a worldwide distribution. This infection displays clear seasonal nature in some regions of the tropics, where the rainy season is marked by high temperatures. Household and wild animals carry leptospires and contribute to their dissemination in nature. Transmission mainly occurs by contact with water contaminated with the urine of infected animals, and consequently, it is quite widespread especially in times of rain, since many areas are subject to flooding and have poor sanitation. Serological tests demonstrate that Leptospira sp. infection in horses occurs worldwide and that the predominant serovar may vary depending on the region or infection sources. Besides systemic and ocular manifestations, leptospirosis in horses has been recognized as an important disease of the reproductive system, since it leads to the birth of weak foals, stillbirths or neonatal mortality, and mainly to abortion, usually after the sixth month of pregnancy. In this context, this review aims to gather and discuss information about the role of leptospirosis in reproductive disorders in horses.

Diagnosis and control of an outbreak of leptospirosis in goats with reproductive failure

This study presents a Brazilian goat herd with reproductive failure over 2009-2010, in which there were abortions (22/50; 44%), embryonic resorption (6/50; 12%) and neonatal deaths (2/50; 4%). A diagnosis of leptospirosis was made, based on serology (microscopic agglutination test - MAT), bacterial culture, and polymerase chain reaction (PCR). Antibiotic therapy, specific vaccination protocols and changes in management practices were instigated. One year after the outbreak, diagnostic methods were repeated and reproductive performance re-analysed. Soon after the outbreak, 61/125 (48.8%) of the goats were seropositive for Leptospira. Pure isolates of Leptospira were not obtained, but Leptospira PCR testing was positive in 48/50 (96%) urine samples. After 1 year only 4.2% were seropositive and the occurrence of reproductive problems decreased roughly 10-fold, although five goats (10.4%) remained PCR-positive. A broad-based management approach, including serological and molecular diagnostic methods, vaccination, antibiotic treatment, and alteration of some environmental aspects, were critical to the control of this outbreak, thereby minimising subsequent reproductive failures and economic losses.

Isolation of Leptospira interrogans Hardjoprajitno from vaginal fluid of a clinically healthy ewe suggests potential for venereal transmission.

A total of 15 adult ewes from one flock known to be seroreactive for leptospirosis was studied. Urine and vaginal fluid were collected from each animal to test for the presence of leptospires using bacterial culture and conventional PCR methods. One pure culture of Leptospira sp. was obtained from the vaginal fluid sample of a non-pregnant ewe. The isolate was characterized by DNA sequencing of the rrs and secY genes, variable-number of tandem-repeats (VNTR) analysis and serogrouping, and the isolate was typed as Leptospira interrogans serogroup Sejroe serovar Hardjo type Hardjoprajitno. This report indicates the presence of viable Leptospira in the vaginal fluid of a ewe, suggesting the potential for venereal transmission of leptospires in sheep.

Progestin-impregnated intravaginal sponges for estrus induction and synchronization influences on goats vaginal flora and antimicrobial susceptibility

The objective was to characterize vaginal bacteria, their antimicrobial sensitivity, and the incidence of vaginitis, in goats before and after insertion of intravaginal sponges containing progesterone. Sponges were inserted in 37 Saanen goats and removed after 6, 9 or 12d (G6, G9 and G12). At sponge removal, all goats had clinical signs of vaginitis. Sampling was conducted just before sponge insertion and at 0, 24, 48, and 72 h after sponge removal. Vaginal secretions were subjected to standard bacteriological procedures, including isolation of bacteria, subculture, and determination of sensitivity to antimicrobials (gentamicin, cefalotin, tetracycline, ciprofloxacin, trimethoprim-sulfamethoxazole, amoxicillin and clavulanic acid, penicillin G and cefoxitin). Ciprofloxacin, gentamicin, tetracycline and trimethoprim-sulfamethoxazole were the most effective for coliforms (100% sensitivity), whereas ciprofloxacin, gentamicin and tetracycline were the most effective for cocci (100, 98.6 and 97.2% sensitivity, respectively). In contrast, the least effective antimicrobials were cefalotin for the coliforms, and penicillin for the cocci (37.5 and 64.4% sensitivity, respectively), regardless of duration of implant presence and interval from implant removal to sampling. In conclusion, insertion of intravaginal progestin-impregnated sponges induced clinical vaginitis in goats. Members of Staphylococcus genus were the most frequently recovered species of the vaginal samples cultured, and all isolates were resistant to several antimicrobials.

Detection of Anti-Leptospira Antibodies in Captive Nonhuman Primates From Salvador, Brazil

Leptospirosis is a widely distributed zoonosis that affects several species of domestic and wild animals. Under captive conditions, Leptospirosis is a potential problem because the physical conditions in most zoos and research centers cannot prevent the captive animals from being exposed to rodents, raccoons, opossums, and other local wildlife that are known carriers. Yet, despite the potential risk, animals that are destined for reintroduction into the wild are not routinely tested for anti‐Leptospira antibodies before their release. The purpose of this study was to determine the occurrence of anti‐Leptospira antibodies in captive New World monkeys that were housed in the Wild Animals Screening Center in Salvador, Brazil. Blood samples were collected from 44 monkeys (28 Callithrix jacchus, eight Callithrix pennicilata, and eight Cebus sp.). The animals were screened for antibodies with the microscopic agglutination test. Twenty‐five (56.8%) primates were seroreactive, with Icterohaemorrhagiae being the most frequent serogroup. None of the monkeys, however, presented clinical signs of leptospirosis. Thus, seroreactivity with low titers in asymptomatic animals, as observed in this study, suggests exposure to the agent. The unexpected predominance of the serogroup Icterohaemorrhagiae further suggests that exposure to this serogroup occurred in captivity. Therefore, the dangerous possibility cannot be ignored that reintroduced monkeys will carry the leptospiral serovars into wild populations. In conclusion, primates exposed to urban serovars before their release from captivity represent a potentially significant health risk to wild populations. Am. J. Primatol. 74:8–11, 2012.

Antimicrobial susceptibility of Staphylococci isolated from naturally occurring canine external ocular diseases

OBJECTIVE The purpose of this study was to describe the species distribution and antimicrobial susceptibility patterns of Staphylococci isolated from naturally occurring canine ocular diseases. SAMPLES AND PROCEDURES: Samples obtained from 68 dogs with signs of external eye disease were processed for isolation of bacteria of the genus Staphylococcus sp. Isolates were identified by biochemical reactions and tested for susceptibility to 11 antimicrobials of six classes. RESULTS Forty (58.8%) samples yielded Staphylococcus sp. in pure culture. Coagulase-positive Staphylococci were most common and Staphylococcus intermedius was the most frequent (45%) species, followed by S. aureus (22.5%) and the coagulase-negative species S. epidermidis (20%), and S. simulans (12.5%). Resistance to at least one drug was observed in 92.5% of the isolates, and multidrug resistance was a common finding (72.5%). The most effective drugs against Staphylococcus strains isolated from extra-ocular canine ocular diseases were ceftiofur and cefalexin. CONCLUSION This study highlights the presence of Staphylococcus sp. genus in naturally occurring extra-ocular canine ocular disease and the emergence of resistant strains to common antimicrobial drugs. It also emphasizes the need for bacterial culture with species identification and susceptibility testing in order to choose the appropriate antimicrobial therapy.

Infection by Leptospira spp. in cattle in a tropical region, Rio de Janeiro, Brazil.

Dear Sir: We read with interest the study reported by Ayral and others1 entitled “Distribution of Leptospira serogroups in cattle herds and dogs in France.” Ayral and others1 concluded that the inventory of infecting Leptospira serogroups revealed that current vaccines in France are not fully capable of preventing leptospirosis. In total, 394 cattle were diagnosed with clinical leptospirosis, and the results suggested infection by serogroups Australis (43%), Sejroe (33%), and Grippotyphosa (17%). We share our experience with bovine leptospirosis in Brazil and compare it with the scenario described in France. Infected cattle are commonly asymptomatic and may shed the bacterium in urine for long periods.2 Serology by microscopic agglutination test (MAT) is recommended as the primary diagnostic tool, although it is considered reliable only at the serogroup level.3 Although useful for a diagnosis at the herd level, serology is not adequate for the individual detection of carriers,4 which may impair control programs.5 For individuals, a rapid, sensitive, and reliable diagnostic tool, such as polymerase chain reaction (PCR), is required. In a study conducted by our group in 2013, 208 cows were randomly selected in a slaughterhouse located close to Rio de Janeiro, Brazil. After clinical pre-slaughter examination, the animals were considered free of signs of leptospirosis. Blood samples (208) for serology (MAT)3 and urine samples (199) from direct puncture of the bladder for PCR-lipL325 and culture were obtained. Serology showed that 77 of 208 (37%) animals were reactive, with serogroup Sejroe by far the most frequent (62.3%) followed by Javanica (7.8%), Icterohaemorrhagiae (6.5%), Grippotyphosa (3.9%), and Tarassovi (3.9%). Urine PCR showed that 67 of 199 animals (33.6%) were positive. Additionally, 10 isolates were obtained in pure culture, including serogroups Sejroe, Shermani, and Grippotyphosa with 2 isolates each and Sarmin, Tarassovi, Autumnalis, and Panama with 1 isolate each. These results showed a high rate of asymptomatic shedding in cows. Members of serogroups Grippotyphosa, Autumnalis, and Panama are usually associated with environmental contamination and maintained by wildlife species. Serogroup Sejroe is the most common in ruminants worldwide as well as in Brazil.6 Serogroups Sarmin, Shermani, and Tarassovi have never previously been reported from cattle in Brazil and may have been neglected as agents of bovine leptospirosis. Serogroup distribution differed between Brazil and France. In our study, both seronegative and seroreactive cows were shedding leptospires. Therefore, the direct detection of leptospires in urine by culturing or PCR is an important tool for the success of control programs in cattle. Additionally, an active surveillance approach should also include asymptomatic animals, because they may shed the bacterium to the environment and consequently, play an important role in the epidemiology of leptospirosis.

Pulmonary hemorrhage in horses seropositive to leptospirosis

The aim of this study was to verify the occurrence and severity of pulmonary hemorrhage (PH) in horses seropositive or not to leptospirosis. A total of 84 training horses were tested for anti-Leptospira antibodies and submitted to endoscopy of the upper airways 30-60 minutes after exercise. Forty-nine (46.4%) horses were seropositive (titer>100) to serovar Copenhageni. Seventeen horses (20.2%) presented PH in different grades, significantly more commonly observed in seropositives (34.7%) than seronegatives (8.6%) (p<0.05), and also more severe in the first. Additionally, a seropositive horse is 4.26 times more likely (OR) to present PH than a seronegative one. Fifteen days after specific antibiotic treatment for leptospirosis a significant improvement in grade of hemorrhage was observed. Therefore it is suggested that leptospirosis may potentiate the severity of PH and that specific antibiotic treatment directed towards leptospirosis may help to control the disease.