Strangles is considered an important equine contagious bacterial caused by Streptococcus equi. This study planned to evaluate the seroprevalence of anti-S. equi antibodies in horses located in Mosul city, Iraq for the first time. The sera were collected from 184 animals (156 horses and 28 donkeys), and then they were screened by using indirect ELISA (iELISA) to effectively check the seroconverted animals. The results of this study showed that the total prevalence rate of strangles in horses was 12%, (0.0% in donkeys) and the seroprevalence rate in animals less than 3 years old was 20%, while in animals of ages 3 years and more, it was 7% (P< 0.05). The seroprevalence rate in racing and horses with respiratory signs was significantly higher than ones with Draught and apparently normal conditions (P< 0.05). Any significant relationship was not found between seropositive animals and sex, and among racing horses (P< 0.05). To close, the presence of anti-S. equi antibodies in the examined horses might require more attention to reduce the incidence of the disease in horse breeding centers found in the study zone.

OBJECTIVE To quantify and characterize pleural fluid collected from healthy dogs after placement of a thoracostomy tube (TT). ANIMALS 8 healthy Coonhound-cross dogs (mean ± SD weight, 27.2 ± 1.6 kg). PROCEDURES Thoracic CT of each dog was performed before placement of a TT and daily thereafter for 7 days. Thoracic fluid volume was calculated from CT images. Effusion was aspirated when detected; volume was recorded, and cytologic analysis and bacterial culture were performed. RESULTS Mean ± SD volume of pleural effusion detected by CT was 1.43 ± 0.59 mL/kg (range, 0.12 to 3.32 mL/kg). Mean volume collected via aspiration was 0.48 ± 0.84 mL/kg (range, 0 to 2.16 mL/kg). Cytologic analysis yielded results consistent with an exudate, characterized by septic suppurative inflammation in 6 dogs and mixed inflammation in 1 dog; there was insufficient volume for analysis in 1 dog. Sufficient volume was obtained for bacterial culture for 6 dogs, which yielded pure growths of Staphylococcus pseudintermedius (n = 3) and Streptococcus equi subspecies zooepidemicus (2) and mixed growth of both of these species (1). The TT was removed before day 7 in 4 dogs because of pyothorax (n = 3) and irreversible damage to the TT (1). CONCLUSIONS AND CLINICAL RELEVANCE Presence of a TT induced a minimal volume of pleural effusion in healthy dogs. Pyothorax developed in most dogs between 4 and 6 days after TT placement. On the basis of these findings, a TT should be removed by the fourth day after placement, unless complications are detected sooner.

A total of 22 clinical streptococcal isolates, predominantly Streptococcus zooepidemicus, associated with endometritis in horses were tested for their ability to withstand the natural bactericidal properties of freshly obtained blood. During a 3-hour incubation in blood from a single horse, 8 of these isolates survived and grew; the remainder were killed. To determine whether this ability to grow extended to blood of other horses, 5 of these growing isolates were tested for their ability to grow in the blood of 5 additional horses. The same 5 horses were used for each isolate. The isolates grew in blood of some of the horses, but were killed in blood of the others. However, the horse's blood that mediated killing was different for each isolate. Killing required leukocytes, but the specificity for killing appeared to reside in plasma, although plasma by itself was not bactericidal. Heat-stable and heat-labile components in plasma, interpreted as antibody and complement, respectively, appeared necessary for killing. Isolates that could grow in fresh blood lost this ability after 10 passages in artificial media. Results of these experiments of phagocytosis in fresh blood may provide helpful insights into the phagocytosis of S zooepidemicus in equine uterine f1uid.

A double-blind randomized clinical trial was undertaken to determine the value of parenterally administered Streptococcus equi M-protein vaccine in foals during an epizootic of strangles. Weaned mixed-breed foals (n = 664) housed on 2 adjacent feed-lots (A and B) arrived over a 5-day period, 2 weeks before primary vaccination. Foals in lot B (n = 114) were randomly administered vaccine (n = 59) or saline solution (placebo; n = 55) on 3 occasions at biweekly intervals. Foals in lot A (n = 450) were given 1 dose of vaccine (n = 225) or placebo. The following clinical observations were scored blindly by a single observer for all foals in lot B and for 120 (randomly sampled) foals in lot A on a single day, 2 (lot B) and 6 (lot A) weeks after final vaccination: cervical lymphadenopathy, type of bilateral nasal discharge, and palpable swelling at injection site(s). Bacteriologic culture of nasal swab specimens or lymph node aspirates from selected foals with clinical disease yielded S equi. Cervical lymphadenopathy was observed in 17 of 59 (29%) vaccinates and 39 of 55 (71%) nonvaccinated controls in lot B and in 32 of 60 (53%) vaccinates and 29 of 60 (48%) controls in lot A. Contingency X2 analysis confirmed significantly lower cervical lymphadenopathy rate (X2 = 18.5; P < 0.001) and prevalence of mucopurulent nasal discharge (X2 = 11.4; P < 0.01) for vaccinates in lot B only. Swelling(s) at the vaccine injection site were palpated in 44% of lot B and 29% of lot A vaccinates vs < 2% of placebo controls. In the face of intense natural exposure, foals inoculated 3 times with M-protein vaccine were less than half as likely to have clinical signs of strangles as were nonvaccinated horses.

Adherence of Streptococcus dysgalactiae isolates from cattle and S equi isolates from horses to their respective host epithelial cells was compared with the adherence of S pyogenes to human epithelial cells. The adherence was quantitatively determined by use of fluorescein-labeled streptococci. All 3 streptococcal species adhered selectively to their respective host cells. The mechanism of adherence was evaluated by binding studies with adhesive plasma protein, fibronectin. Although all 3 streptococcal species bound fibronectin, S dysgalactiae and S equi interacted preferentially with a 210-kilodalton (kD) C-terminal fragment of fibronectin, whereas S pyogenes bound only a 29-kD N-terminal fragment. A synthetic peptide Gly-Arg-Gly-Asp-Ser, representing the host cell attachment site of fibronectin, partially inhibited the binding of fibronectin and of its 210 kD fragment to S dysgalactiae, but not to S equi. The binding of fibronectin and its 29-kD fragment to S pyogenes was not inhibited by Gly-Arg-Gly-Asp-Ser. These differences in binding activities corresponded to the ability of fibronectin to mediate the adherence of the streptococci to the epithelial cells: fibronectin strongly inhibited the adherence of S pyogenes and S equi to the epithelial cells, but only weakly inhibited that of S dysgalactiae.

The study was designed to review the occurrence of Streptococcus equi (S. equi) infection in Egyptian Arabian horses, investigate the virulence gene and phage-related bacterial superantigens (SeeM, seeI, SeeH, and SeeL) of S. equi in the isolates, and evaluate the hematological and serum biochemical characteristics of horses with its infection. A total of 100 horses were examined, with 80 having respiratory tract infections and 20 healthy horses. Samples of nasal swabs, pus, and blood were collected for laboratory diagnosis. Bacterial isolation, identification, and molecular diagnosis of S. equi were performed using a polymerase chain reaction. 34% of samples from diseased horses were detected for S. equi, and the antimicrobial susceptibility pattern of S. equi revealed that Penicillin G was highly effective, followed by Ceftiofur, while ampicillin and tetracycline were less effective. S. equi showed high resistance to Vancomycin and Chloramphenicol. Molecular characterization of S. equi revealed that the 16S rRNA gene, sodA gene, seM gene, SeeM gene, and seeI gene were amplified in all tested isolates. Further analysis showed that three isolates were optimistic for the virulence gene SeeH, while the SeeL gene was found in two isolates. The hematological and biochemical analysis revealed that Arabian horses that were strangled exhibited anemia, leukocytosis, and neutrophilia. Additionally, there was an increase in the levels of total proteins, serum globulins, serum AST, potassium, and phosphorus. Conversely, there was a decrease in the levels of albumin, calcium, and sodium in the affected horses, while creatinine and urea showed no significant changes. Treatment with penicillin resulted in an improvement in all. The study underscores the importance of taking appropriate measures to prevent and control S. equi infection in horses to minimize the potential impact on animal health and economic losses.

Equine endometria representative of Kenney's categories I, II, and III were incubated in vitro with phosphate buffer, Streptococcus pneumoniae, or S zooepidemicus. Endometrial tissues from mares in estrus and diestrus were first categorized according to Kenney's classification, then were tested for adherence of S pneumoniae and S zooepidemicus to the epithelia. Bacteria were not observed when the endometrial tissue was incubated with phosphate buffer or S pneumoniae. There was no statistical difference in attachment of S zooepidemicus to endometrial tissue from mares in estrus or diestrus if endometrial classification was ignored. However, bacterial attachment was significantly (P less than or equal to 0.05) higher in category III endometrium during estrus.

Strangles is an extremely contagious bacterial infection specific to&#xD;equine species( horses, mules and zebras). A nationwide screening of S. equi was conducted among horses following an isolation of Streptococcus equi subsp. equi (S. equi) from a horse. All horses were monitored for the presence of respiratory signs, nasal discharge and submandibular swelling. This paper reports the isolation of S. equi from horses during a nationwide survey from August 2010 to December 2010. From August 2010 to December 2010 our laboratory received 2,825 nasal swabs, 9 guttural pouch flushes, 1 submandibular swab and 1 submandibular abscess. The samples were subjected to conventional bacterial isolation and identification.&#xD;Streptococcus equi-positive samples were also confirmed by detecting the M-gene (SeM) of the bacteria by using PCR. Two nasal swabs from two horses and one submandibular abscess from a horse were positive for S. equi by culture and subsequently by PCR. Surveillance for S. equi should be continued for the control of the strangles. PCR can be carried out in parallel to bacterial culture to increase the&#xD;detection rate of carriers and shedders.