Prevalence of Hoarseness and Its Association with Severity of Dysphagia in Patients with Sarcopenic Dysphagia

OBJECTIVES

To investigate the prevalence of hoarseness and its association with the severity of dysphagia in patients with sarcopenic dysphagia.

DESIGN

Cross-sectional study using the Japanese sarcopenic dysphagia database.

SETTING

19 hospitals including 9 acute care hospitals, 8 rehabilitation hospitals, 2 long-term care hospitals, and 1 home visit rehabilitation team.

PARTICIPANTS

287 patients with sarcopenic dysphagia, aged 20 years and older.

MEASUREMENTS

Sarcopenic dysphagia was diagnosed using a reliable and validated diagnostic algorithm for the condition. The presence and characteristics of hoarseness classified as breathy, rough, asthenic, and strained were assessed. The prevalence of hoarseness and the relationship between hoarseness and Food Intake LEVEL Scale (FILS) were examined. Order logistic regression analysis adjusted for age, sex, naso-gastric tube, and handgrip strength was used to examine the relationship between hoarseness and FILS at baseline and at follow-up.

RESULTS

The mean age was 83 ± 10 years. Seventy-four (26%) patients had hoarseness, while 32 (11%), 20 (7%), 22 (8%), and 0 (0%) patients had breathy, rough, asthenic, and strained hoarseness, respectively. Median FILS at the initial evaluation was 7 (interquartile range, 5-8). Hoarseness (β=0.747, 95% confidence intervals= 0.229, 1.265, p=0.005), age, sex, naso-gastric tube, and handgrip strength were associated independently with baseline FILS, while hoarseness (β=0.213, 95% confidence intervals= -0.324, 0.750, p=0.438) was not associated independently with the FILS at follow-up.

CONCLUSIONS

Hoarseness was associated with the severity of dysphagia at baseline, however not a prognostic factor for sarcopenic dysphagia. Resistance training of swallowing and respiratory muscles and voice training as part of rehabilitation nutrition might be useful for treating sarcopenic dysphagia.

Association between Inflammation and Functional Outcome in Patients with Sarcopenic Dysphagia

OBJECTIVES

This study aimed to investigate whether inflammation affects the outcome of swallowing ability to improve treatment for sarcopenic dysphagia.

DESIGN

A retrospective observational cohort study was performed using data from the Japanese sarcopenic dysphagia database.

SETTING

The database was constructed using data from 19 hospitals and one home visiting rehabilitation team.

PARTICIPANTS

Patients with sarcopenic dysphagia with measurements of C-reactive protein (CRP) and serum albumin (Alb) were included.

MEASUREMENTS

Patients were assigned to two groups using CRP, Alb, and the Japanese modified Glasgow Prognostic Score (mGPS). The Food Intake LEVEL Scale (FILS) was measured at the times of admission and follow-up (FILS follow-up) to assess swallowing function.

RESULTS

A total of 197 patients were included. Mean or median values of each parameter were as follows: age: 83.8±8.7, Alb: 3.2 ± 0.6 g/dL, CRP: 8.0 [3.0, 29.0] mg/L, mGPS: 1 [1-2], FILS: 7 [6-8], FILS follow-up: 8 [7-8], and duration of follow-up: 57.0 [27.0, 85.0] days. The FILS score at follow-up was significantly lower in the high CRP group (≥ 5.0 mg/L) than in the low CRP group (< 5.0 mg/L) (p = 0.01). Further, the FILS score at follow-up was significantly lower in the high mGPS group (class; 2) than in the low mGPS group (class; 0 and 1) (p = 0.03). In the multiple linear regression analyses without FILS at baseline, CRP and mGPS were independent risk factors for FILS follow-up. When FILS at baseline was entered, CRP and mGPS were not an independent risk factors for FILS follow-up.

CONCLUSIONS

Inflammation could modify the outcome of the patients with sarcopenic dysphagia. Inflammation may be an important risk factor in evaluating patients with sarcopenic dysphagia.

Construction and Quality Evaluation of the Japanese Sarcopenic Dysphagia Database

OBJECTIVES

To describe the activity and evaluate the quality of the Japanese sarcopenic dysphagia database.

DESIGN

Cohort registry study.

SETTING

19 hospitals including 9 acute care hospitals, 8 rehabilitation hospitals, 2 long-term care hospitals, and 1 home visit rehabilitation team.

PARTICIPANTS

467 dysphagic patients, aged 20 years and older.

MEASUREMENTS

The following indices were assessed at baseline: age, sex, main disease, sarcopenic dysphagia, whole body sarcopenia, Food Intake Level Scale (FILS), malnutrition diagnosed by the Global Leadership Initiative on Malnutrition criteria, oral status assessed by the Revised Oral Assessment Guide or the Oral Health Assessment Tool, activities of daily living assessed by the Functional Independence Measure (FIM) or the Barthel Index (BI), Charlson comorbidity index, C-reactive protein and serum albumin levels, dysarthria, hoarseness, aphasia, pressure ulcers, bladder, bowel, and kidney function, respiratory status, polypharmacy, number of drugs, and involvement of health care professionals and rehabilitation nutrition team. FILS, FIM or BI, and outcome including discharge destination were assessed at follow-up. A simple comparison of cases and evaluation of the quality of data were performed.

RESULTS

The mean age was 80.4 ± 11.4 yr. The variable input error was 0. The number of patients with missing data was high for estimated glomerular filtration rate, C-reactive protein, serum albumin, skeletal mass index, and tongue pressure. The prevalence of either probable, possible, or no sarcopenic dysphagia was 105 (23%), 182 (39%), or 179 (38%), respectively. Doctors including physiatrists, nurses, physical therapists, and registered dietitians were involved with most patients, while the rehabilitation nutrition team was involved in only 16% of patients.

CONCLUSIONS

The quality of the database was relatively high. Sarcopenic dysphagia is common in patients with dysphagia.

Positive Effects of "Textured Lunches" Gatherings and Oral Exercises Combined with Physical Exercises on Oral and Physical Function in Older Individuals: A Cluster Randomized Controlled Trial

OBJECTIVES

Proper nutrition and physical exercises are essential to prevent frailty in older adults. Proper masticatory performance and oral function may influence on physical activities as well since the mouth is the entrance of nutrition and digestion. Thus, the present study aimed to test the combined program of specially devised lunch gatherings containing textured foods with oral and physical exercises on the improvement of oral and physical function in community-dwelling older adults.

DESIGN

A Cluster randomized controlled trial; Setting and Participants: Eighty-six community-dwelling older adults in Daito city, Japan, were randomly assigned into control (n = 43) or intervention (n = 43) groups.

INTERVENTION

The control group performed the physical exercise regimen only. The intervention group participated in a 12-week physical and oral exercise program and ate a so-called "munchy lunch" that introduced textured foods with proper nutrients together after performing the physical exercise twice a week following brief dietary instruction at the intervention onset. Physical training and lunch gatherings were held at local public centers.

MEASUREMENTS

The differences in measured variables for physical and oral function between baseline and 12 weeks of intervention were statistically tested.

RESULTS

Oral function as measured by tongue pressure increased significantly in the intervention group (p=0.031), but not in the control group. Physical properties and activities, including body fat percentage and results of the timed up and go test, decreased more significantly in the intervention group than in controls (p<0.05).

CONCLUSIONS

Our findings suggest that a combined program of textured lunch gatherings with oral and physical exercises may improve physical and oral function as a preventative approach for frailty in community-dwelling older adults.

Regulation of allergic airway inflammation by adoptive transfer of CD4+ T cells preferentially producing IL-10

Anti-inflammatory pharmacotherapy for asthma has mainly depended on the inhalation of glucocorticoids, which non-specifically suppress immune responses. If the anti-inflammatory cytokine interleukin (IL)-10 can be induced by a specific antigen, asthmatic airway inflammation could be suppressed when individuals are exposed to the antigen. The purpose of this study was to develop cellular immunotherapeutics for atopic diseases using IL-10-producing CD4⁺ T cells. Spleen cells isolated from ovalbumin (OVA)-sensitized mice were cultured with the antigen, OVA and growth factors, IL-21, IL-27 and TGF-β for 7 days. After the 7-day culture, the CD4⁺ T cells were purified using a murine CD4 magnetic beads system. When the induced CD4⁺ T cells were stimulated by OVA in the presence of antigen-presenting cells, IL-10 was preferentially produced in vitro. When CD4⁺ T cells were adoptively transferred to OVA-sensitized mice followed by intratracheal OVA challenges, IL-10 was preferentially produced in the serum and bronchoalveolar lavage fluid in vivo. IL-10 production coincided with the inhibition of eosinophilic airway inflammation and epithelial mucus plugging. Most of the IL-10-producing CD4⁺ T cells were negative for Foxp3 and GATA-3, transcription factors of naturally occurring regulatory T cells and Th2 cells, respectively, but double positive for LAG-3 and CD49b, surface markers of inducible regulatory T cells, Tr1 cells. Collectively, most of the induced IL-10-producing CD4⁺ T cells could be Tr1 cells, which respond to the antigen to produce IL-10, and effectively suppressed allergic airway inflammation. The induced Tr1 cells may be useful for antigen-specific cellular immunotherapy for atopic diseases.

Truncated surface protective antigen (SpaA) of Erysipelothrix rhusiopathiae serotype 1a elicits protection against challenge with serotypes 1a and 2b in pigs

Erysipelothrix rhusiopathiae is a causal agent of swine erysipelas, which is of economic importance in the swine industry by virtue of causing acute septicemia, chronic arthritis, and endocarditis. However, little is known about the genetic properties of its protective antigens. Recently, a surface protective antigen (SpaA) gene was identified from serotype 2 in a mouse model. We cloned spaA from virulent strain Fujisawa (serotype 1a) and determined that the N-terminal 342 amino acids without C-terminal repeats of 20 amino acids have the ability to elicit protection in mice. Fusions of 342 amino acids of Fujisawa SpaA and histidine hexamer (HisSpa1.0) protected pigs against challenge with both serotype 1 and serotype 2, the most important serotypes in the swine industry. Pigs immunized with HisSpa1.0 reacted well with both HisSpa1.0 and intact SpaA by enzyme-linked immunosorbent assay and immunoblotting. Serum collected at the time of challenge from a pig immunized with HisSpa1. 0 markedly enhanced the in vitro phagocytic and killing activity of pig neutrophils against the bacteria. DNA sequences of protective regions of spaA genes from five strains of serotypes 1 and 2 were almost identical. The full DNA sequences also seemed to be conserved among strains of all 12 serotype reference strains harboring the spaA gene by restriction fragment length polymorphism analysis of PCR products. These results indicates that SpaA is a common protective antigen of serotypes 1 and 2 of E. rhusiopathiae in swine and will be a useful tool for development of new types of vaccines and diagnostic tools for effective control of the disease.

An enzyme-linked immunosorbent assay (ELISA) for the detection of antibody against Streptococcus suis type 2 in infected pigs

An ELISA test for the detection of antibody against S. suis type 2 in pigs was developed and applied to field sera. The best sensitivity and specificity of ELISA were obtained when a purified polysaccharide antigen was used. It showed no cross reaction with sera against other serotypes of S. suis and other pathogenic bacteria. A total of 264 sera were collected from 20 pig farms and examined with the antibody against S. suis type 2. In the affected farms, 17.0% of pigs tested were positive, 9.8% in the adjacent farms, but only 3.4% in the free farms. The difference of the positive percentages between the affected and the free farms was statistically significant (P < 0.05).

Humoral immune responses to Theileria parva in cattle as measured by two-dimensional western blotting

Humoral immune responses to schizont antigens from six stocks of Theileria parva were compared by two-dimensional Western blotting using sera from cattle that had been infected with a T. parva stock or a clone. Isoelectric points of a polymorphic immunodominant molecule (PIM) of schizonts that induces strong antibody responses in cattle ranged from acidic to basic. Molecular masses (Mr) of the PIM of the respective T. parva stocks were as follows: T. parva Muguga, 86 kDa; Mariakani, 83 kDa; Marikebuni, 83 kDa; Uganda, 83 kDa; T. parva Boleni, 83 kDa; and T. parva 7014, 100 kDa. Among nine cattle infected with T. parva Muguga, four produced antibodies to a basic antigen having an Mr of 32 kDa. The PIM of T. parva Muguga, T. parva Boleni, and T. parva 7014 reacted strongly with serum obtained from an animal that had been infected with T. parva Muguga. Two-dimensional Western blotting using antischizont monoclonal antibodies enabled us to differentiate between stocks of T. parva.

Experimental infections of mice and pigs with Streptococcus suis type 2

Five inbred strains of mice were tested for their susceptibility to Streptococcus suis type 2 including the type strain, two isolates from meningitis in pigs and two isolates from tonsils of clinically healthy pigs. C57BL/6, ICR and ddY strain mice showed lower susceptibility to all strains of S. suis type 2 than BALB/c and SS strain mice. The type strain and the isolates from diseased pigs produced septicaemia and meningitis in BALB/c and SS mice inoculated with 10(8) colony forming unit of the bacteria and 60 to 100% of these infected mice died. On the other hand, mice inoculated with the isolates from healthy pigs showed mild clinical signs but none of them died. In BALB/c mice which died or developed nervous signs, the purulent meningo-encephalitis, myocarditis, ophthalmitis, labyrinthitis and otitis media were observed. S. suis type 2 antigen was demonstrated in these lesions by immunoperoxidase staining using rabbit S. suis type 2 antiserum. These results were similar to those in the experimentally infected pigs with these virulent and avirulent strains against mice. These results indicate that BALB/c and SS strains of mice are useful as an experimental model of S. suis type 2 infections in pigs, and that there are virulent and avirulent strains against mice and pigs among the strains of S. suis type 2.

Suppressive effect of nonviable Mycobacterium paratuberculosis on the delayed-type hypersensitivity reaction to sheep erythrocytes in mice

The effect of nonviable Mycobacterium paratuberculosis on the delayed-type hypersensitivity reaction to sheep erythrocytes (SRBC) in mice was evaluated by means of delayed-type footpad swelling. Intraperitoneal (i.p.) injection with nonviable M. paratuberculosis into mice from 28 days before to 1 day after immunization with SRBC resulted in a significant suppression of foot-pad swelling to SRBC. The suppressive effect could be transferred by i.p. injection of spleen cells or peritoneal exudate cells from mice which had been pre-treated with nonviable M. paratuberculosis into non-treated recipient mice. The suppressive effect of spleen cells was retained even after passing them through a nylon wool column. The suppressive effect of spleen cells was abolished by treatment with anti-Thy 1.2 monoclonal antibody plus complement or anti-Lyt 2.2 monoclonal antibody plus complement. However, treatment of spleen cells with anti-mouse gamma globulin antiserum plus complement or anti-Lyt 1.2 monoclonal antibody plus complement did not affect the suppressive effect of spleen cells. The suppression of footpad swelling to SRBC induced by pre-treatment with nonviable M. paratuberculosis could be reversed by i.p. administration of cyclophosphamide. Serum antibody response to SRBC in mice was not affected by pre-treatment with nonviable M. paratuberculosis. These findings indicate that T cells appear to be involved in the suppression of delayed-type hypersensitivity reaction to SRBC in mice by pre-treatment with nonviable M. paratuberculosis.

Evaluation of enzyme-linked immunosorbent assay in comparison with complement fixation test for the diagnosis of subclinical paratuberculosis in cattle

An enzyme-linked immunosorbent assay (ELISA) was evaluated and compared in parallel with the standard complement fixation test (CFT) for the diagnosis of bovine subclinical paratuberculosis. Bovine sera preabsorbed with the mixture of Mycobacterium phlei and kaolin suspension were assayed for antibody activities to the crude protoplasmic antigen of Mycobacterium paratuberculosis in the ELISA. ELISA antibody titer was expressed as ELISA antibody index (EAI) value: EAI = (At-An)/(Ap-An), where At, Ap and An are the absorbance values of a 1:200 dilution of unknown test sera, a 1:400 dilution of positive control serum, and a 1:200 dilution of negative control serum. An EAI of 0.6 or greater was established as a reasonable cutoff point for a positive antibody titer by ELISA. Of the 156 sera from cattle with subclinical M. paratuberculosis-infection, 106 (67.9%) were positive by ELISA and 41 (26.3%) by CFT. Of the 3,880 sera from cattle in the herds which had no history or evidence of paratuberculosis, 3,875 (99.9%) were negative by ELISA, and 3,787 (97.6%) by CFT. Positive ELISA titers were detectable 1 to 5 months earlier than positive CFT titers in experimentally infected cattle, and 7 to 10 months earlier in naturally infected cattle. These results indicate that the ELISA should replace the CFT as the routine test of choice for the diagnosis of bovine paratuberculosis.

Cell-mediated and humoral immune responses in mice during experimental infection with Mycoplasma pulmonis

Cell-mediated and humoral immune responses in mice after challenge exposure with Mycoplasma pulmonis were investigated. The cell-mediated immune response was determined by means of the delayed-type footpad swelling and the humoral immune response by means of the indirect haemagglutination test. Delayed-type footpad swelling and serum antibody titres were detected at one week after the challenge exposure and persisted for 7 weeks until the end of the experiment. However, there was a poor correlation between the degree of delayed-type footpad swelling and that of serum antibody titre. Delayed-type footpad swelling in mice with gross pneumonic lesions was less than that of mice with no gross lesions. A weak negative linear correlation was observed between the delayed-type footpad swelling and the number of M. pulmonis isolated from lungs.

Passive hemagglutination test for detection of antibodies against Taylorella (Haemophilus) equigenitalis in sera of mares

The passive hemagglutination (PHA) test was improved to enable the detection of antibodies to Taylorella (Haemophilus) equigenitalis in the sera of mares. Horse red blood cells (RBC) fixed with glutaraldehyde were compared with similarly treated RBC of a cow, pig and sheep for the PHA test. The horse RBC were superior to those of the other animals tested in detecting mares affected with contagious equine metritis (CEM). A PHA test using these cells as indicator and an antigen prepared from T. equigenitalis by sonication following treatment with hyaluronidase was the most satisfactory in terms of sensitivity and specificity. None of the 156 serum samples from clinically healthy mares without a history of contact with T. equigenitalis-infected stallions or mares showed PHA titers greater than 1:32 and only a few samples (7.1%) showed PHA titers of 1:32. Four of the 50 serum samples from mares affected with CEM showed PHA titers of 1:32, while most of the samples (92.0%) showed PHA titers greater than 1:32. The glutaraldehyde-fixed horse RBC sensitized with the antigen had the advantage of being reproducible for at least 7 months when preserved at 4 degrees C.

Cell-mediated and humoral immune response to non-viable Mycoplasma pulmonis in mice enhanced by cross-linked ricin

The enhancing effect of cross-linked ricin (CL-ricin) on the cell-mediated and humoral immune response of mice to non-viable Mycoplasma pulmonis was studied. The cell-mediated immune response was evaluated by means of the delayed-type footpad swelling, and the humoral immune response by means of the indirect hemagglutination test. Mice pre-treated subcutaneously with non-viable M. pulmonis and CL-ricin showed significantly increased delayed-type footpad swelling when they were injected in the footpad with the same antigen 7 days later. Delayed-type footpad swelling was not detected in mice pre-treated only with non-viable M. pulmonis or CL-ricin followed by footpad injection with non-viable M. pulmonis. Injection of non-viable M. pulmonis in the footpad on Days 3, 7, 14, 21, 28, 35 and 42 after pre-treatment with non-viable M. pulmonis and CL-ricin resulted in significant footpad swelling. Delayed-type footpad swelling was transferred by intravenous injection of spleen cells from mice which had been pre-treated 7 days previously with non-viable M. pulmonis and CL-ricin into non-treated recipient mice. Intravenous injection of anti-mouse thymus cell serum into mice previously pre-treated with non-viable M. pulmonis and CL-ricin reduced the delayed-type footpad swelling significantly. Mice pre-treated subcutaneously with non-viable M. pulmonis and CL-ricin showed a marked increase in serum antibody titers compared with those that received non-viable M. pulmonis alone.

Humoral immune response to non-viable Mycoplasma pulmonis in mice enhanced by dextran sulfate

The enhancing effect of dextran sulfate on the humoral immune response to nonviable Mycoplasma pulmonis in mice was evaluated by means of the indirect haemagglutination test. The serum antibody titres in mice immunized subcutaneously with a mixture of non-viable M. pulmonis and dextran sulfate were greater and persisted longer than those in mice immunized with non-viable M. pulmonis alone. DEAE-dextran also enhanced the humoral immune response to non-viable M. pulmonis in mice.

Suppressive effect of nonviable Mycoplasma hyopneumoniae on phytohemagglutinin-induced transformation of swine lymphocytes

The effect of nonviable Mycoplasma hyopneumoniae on transformation of swine peripheral blood lymphocytes by mitogen was investigated. Lymphocyte transformation was evaluated as incorporation of [3H]-thymidine, using a microculture system. Mycoplasma hyopneumoniae was grown in Friis medium, inactivated with sodium azide, and washed with phosphate-buffered saline solution. Four strains of M hyopneumoniae, strain J, strain 11, and 2 low-passage isolates (1361A, 1375C), were found to suppress phytohemagglutinin-induced lymphocyte transformation. Mycoplasma hyopneumoniae strains J, 11, and 1361A reduced lymphocyte transformation by about 50%, whereas strain 1375C reduced lymphocyte transformation by 98.7%. The suppressive effect was abrogated by heating M hyopneumoniae at 60 C or at higher temperatures for 30 minutes. Sonication of the heated M hyopneumoniae cells partially restored the suppressive effect.

Cell-mediated and humoral immune response to Mycoplasma hyopneumoniae in pigs enhanced by dextran sulfate

The effect of dextran sulfate (DS), known to be cytotoxic to macrophages, on the cell-mediated and humoral immune response to nonviable Mycoplasma hyopneumoniae in pigs was investigated. The cell-mediated immune response was determined by means of lymphocyte transformation a test, using uptake of [3H]thymidine in a microculture system and the humoral immune response by means of a microplate complement-fixation test. Peripheral blood lymphocytes from pigs vaccinated with nonviable M hyopneumoniae and DS incorporated substantially more [3H]thymidine than did those from pigs given Mycoplasma or DS alone. The transformation of lymphocytes from M hyopneumoniae-DS vaccinated pigs was enhanced when M hyopneumoniae cells used in the assay system were heated at 60 C for 30 minutes. Similarly prepared M flocculare and M hyorhinis cells also stimulated lymphocytes from M hyopneumoniae-DS vaccinated pigs, but not nearly as great as when M hyopneumoniae cells were used. The humoral antibody response and the cell-mediated immune response to nonviable M hyopneumoniae was markedly enhanced by DS. Pigs were vaccinated with nonviable M hyopneumoniae and/or DS 4 times and challenge exposed intratracheally with viable M hyopneumoniae. Pigs vaccinated with M hyopneumoniae and DS had less severe pneumonia than did nonvaccinated pigs.

Delayed hypersensitivity to nonviable Mycoplasma pulmonis in mice is enhanced by dextran sulfate

The enhancing effect of dextran sulfate (DS) on delayed hypersensitivity to nonviable Mycoplasma pulmonis in mice was evaluated by means of delayed footpad swelling. Mice pretreated subcutaneously with nonviable M. pulmonis and DS had significantly increased delayed footpad swelling when the mice were injected subcutaneously in the footpad with the same antigen 7 days later. Delayed footpad swelling was not detected in mice pretreated only with nonviable M. pulmonis or DS followed by footpad injection with nonviable M. pulmonis. Subcutaneous pretreatment in the scruff of the neck with nonviable M. pulmonis and DS was more effective in eliciting delayed footpad swelling than intravenous or intraperitoneal pretreatment. Delayed footpad swelling did not develop when mice were injected in the footpad with nonviable Mycoplasma hyopneumoniae, M. gallisepticum, M. dispar, or M. bovis on day 7 after pretreatment with M. pulmonis and DS. Injection of nonviable M. pulmonis in the footpad on day 3 after pretreatment with M. pulmonis and DS resulted in no significant footpad swelling, but injection in the footpad on days 7, 14, 21, and 28 resulted in significant footpad swelling. Delayed footpad swelling was transferred by intravenous injection with spleen cells of mice which were pretreated with nonviable M. pulmonis and DS into nontreated recipient mice. Intravenous injection with anti-mouse thymus cell rabbit serum into the mice which were previously pretreated with nonviable M. pulmonis and DS reduced the delayed footpad swelling significantly.

In vitro sensitivities to antimicrobial drugs of ureaplasmas isolated from the bovine respiratory tract, genital tract and eye

The sensitivity to 18 antimicrobial drugs was examined for 66 strains of Ureaplasma sp isolated from respiratory tracts of calves suffering from enzootic pneumonia, urinary tracts of bulls and eyes of cows suffering from infectious bovine kerato-conjunctivitis. Furamizole, tiamulin fumarate, erythromycin lactobionate, malidomycin C, doxycycline hydrochloride, kitasamycin tartrate, tylosin tartrate, T-2636C, tetracycline hydrochloride, oxytetracycline hydrochloride, chlortetracycline hydrochloride, oleandomycin phosphate, furazolidone, spiramycin adipate, chloramphenicol and thiophenicol showed strong inhibiting activity on all the test strains. Among them, furamizole, tiamulin fumarate and erythromycin lactobionate were most active. Kanamycin sulphate showed weak activity on all the strains tested. The differences in origin of the test strains did not affect their sensitivity to any of the drugs.