Cassava (Manihot esculenta Crantz), a highly heterozygous crop, is devastated by cassava mosaic disease (CMD). The discovery of the CMD2 dominant gene is helpful in the genetic analysis of CMD resistance. Molecular markers for CMD2 gene were used to introgress CMD resistance into Latin American cassava genotypes and validated in the field for 4 yr for stability of resistance conferred by CMD2. Field screening identified 64 Latin American genotypes with stable resistance to CMD. Resistance to CMD of two Nigerian cassava cultivars (TMS 97/2205 and TMS 98/0505) was analyzed with markers and in the field. Molecular data indicated that CMD resistance in the two Nigerian cultivars was mediated by the CMD2 gene. Results showed TMS 97/2205 to be highly resistant to CMD in three ecological zones in Nigeria. Further genetic analysis of this genotype as a source of high level of resistance to CMD using a segregating F1 population derived from a TMS 97/2205 × NR 8083 cross was initiated using 530 simple sequence repeat (SSR) markers to identify quantitative trait loci (QTL) for CMD resistance. A marker (NS198) associated with a QTL for CMD resistance, explaining 11% of the phenotypic variance observed, was identified. The combined effect of this QTL and CMD2 may account for the high level of resistance of TMS 97/2205. The resistance profile of the evaluated CMD2 genotypes in growth cycle was not uniform and was affected by genetic background. The discovery of a new QTL (CMD3) for CMD resistance in TMS 97/2205 offers new opportunities for pyramiding CMD genes for enhanced durability of CMD resistance in cassava.

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This study presents Salmonella Enteritidis incidence in chicken layer flocks in Turkey determined by real-time PCR (rPCR) and by International Organization for Standardization (ISO) method 6579:2002/Amd 1:2007. A total of 259 samples, composed of 1,036 individual samples each pooled into 4, including 175 cloacal swab, 14 intestine, 35 gizzard swab, and 35 cecal swab samples, belonging to 6 major companies, were collected from 50 layer flocks and tested by rPCR and ISO culture methods. Overall incidence of Salmonella in layer flocks by rPCR and culture was 61.0 and 55.6%, respectively, where 70.1% of these Salmonella isolates were determined as Salmonella Enteritidis. Incidences of Salmonella Enteritidis in culture-positive samples were 65.3% in cloacal swabs, 50.0% in intestines, 73.9% in gizzard swabs, and 87.5% in cecal swabs. The rPCR results were in 100% agreement (100% sensitivity and specificity) with culture results when cecal swabs were selected as the sample type. The relative accuracy of rPCR was 92.4, 91.4, and 84% for intestine, gizzard, and cloacal swab samples, respectively. As a result, by using rPCR and ISO culture, we determined that the Salmonella Enteritidis incidence in layer flocks in Turkey was high and that the use of cecal swab and intestine samples in Salmonella detection would yield reliable results. To reduce this high Salmonella Enteritidis incidence in layer flocks, Salmonella Enteritidis-specific vaccination should be implemented properly in conjunction with a well-designed biosecurity plan, including verifiable corrective actions.

The presence and species diversity of staphylococci in 250 ground beef and lamb meat samples obtained from Diyarbakir, Turkey were investigated. The presence of the 16S rRNA gene, mecA, nuc, pvl, and femA was analyzed by multiplex PCR. Pheno- and genotypic antibiotic resistance profiles of 208 staphylococci isolates were established. Of the ground beef and ground lamb samples, 86.4% and 62.4% were positive for staphylococci, respectively. Staphylococcus aureus, S. saprophyticus, S. hominis, S. lentus, S. pasteuri, S. warneri, S. intermedius, and S. vitulinus made up 40.8%, 28.8%, 11%, 3.8%, 3.8%, 2.4%, 2.4%, and 2.4% of isolates, respectively. Of the 85 S. aureus isolates, 40%, 47%, and 5.8% carried femA, mecA, and pvl, respectively, whereas the corresponding rates for the 118 coagulase-negative staphylococci (CoNS) were 0%, 10.1%, and 0%, respectively. We determined from the 208 isolates, the highest antibiotic resistances were to tetracycline and oxytetracycline (85.5%), followed by penicillin (51.4%), novobiocin (45.6%), ampicillin (39.9%), and doxycycline (31.7%), using the Clinical and Laboratory Standards Inst. (CLSI) method. All isolates were sensitive to gentamycin, ofloxacin, and tobramycin, but 2.3% of the S. aureus isolates had resistance to vancomycin. The staphylococci isolates carried tet(K), blaZ, tet(L), tet(W), cat, tet(S), tet(M), ermB, ermA, and ermC antibiotic resistance genes at rates of 59%, 51.7%, 36.9%, 31.8%, 27.2%, 27.2%, 24.4%, 18.1%, 7.9%, and 3.9%, respectively.

The object of this study was to detect Salmonella from different chicken samples in same flocks to compare sample types for Salmonella detection by both International Organization for Standardization Method 6579:2002/Amd 1:2007 (ISO) and as molecular by a polymerase chain reaction (PCR) method. Salmonellosis is a zoonotic infection and apart from this, infection can be transmitted via vertically to embryo, and this is very important for breeding flocks. A total of 115 samples, comprised of 451 individual samples each pooled into 3, 4, 5 and 6 including 14 drag swabs, 28 pooled wet faeces, 11 pooled embryonated chicken eggs, 62 pooled cloacal swabs, were collected from 14 chicken layer breeding flocks, and tested by culture method (ISO 6579) and conventional PCR. Overall Salmonella infection rate in chicken layer breeder flocks by PCR and culture was 18.2% (21/115). According to sample type, Salmonella rate in culture positive samples were: 0% (0/14) in drag swabs, 90.9% (10/11) in embryonated chicken eggs, 21.4% (6/28) in wet faeces, 8% (5/62) in cloacal swabs. PCR results were in 100% agreement (100% sensitivity and specificity) with culture results. We determined Salmonella rate in 14 chicken layer breeder flocks by using culture and PCR methods, and the use of embryonated chicken eggs and wet faeces samples, respectively in Salmonella detection would yield reliable results. These results indicate that Salmonella screening can be done together with different types of sample. And the most reliable and high results were taken from embryonated chicken egg samples for layer breeding poultry. As a conclusion, Salmonella infection seems to be the major problem in poultry flocks in Turkey, and both conventional culture method and PCR methods were found sensitive for the detection of Salmonella from poultry with different types of sample.

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The aim of this study was to detect Brucella in samples from aborted fetuses of sheep and cattle in Turkey using PCR and bacteriological analysis, and to determine the sensitivity and specificity of the PCR. Organ homogenates from 38 aborted fetuses of cattle and 56 aborted fetuses of sheep were tested. All organ homogenates were cultured for bacteriological analysis, and all of the homogenates and the Brucella isolates obtained by culture were examined with a commercial PCR kit. On bacteriological analysis, Brucella species were found in 30 (31.9 per cent) of the 94 organ homogenates, eight (21.1 per cent) of which were from cattle and 22 (39.3 per cent) from sheep. Using PCR, a total of 29 (30.9 per cent) homogenates were positive for Brucella species, eight (21.1 per cent) of which were from cattle and 21 (37.5 per cent) from sheep. Compared with the bacteriological method, the diagnostic sensitivity and specificity of the PCR kit used in this study were 83 per cent and 94 per cent, respectively.

This study aimed to determine the prevalence of Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) in breeder flocks showing respiratory symptoms. A total of 77 flocks (2153 tracheal swabs and blood samples) were sampled and all were tested by MG real time PCR (MG-rPCR) and MG-ELISA, and 32 flocks were tested by MS real time PCR (MS-rPCR). In the first part of this study covering 28 flocks, all samples from chickens with marked clinical symptoms and high MG-antibody levels gave negative results with MG-rPCR1. Therefore, the MG-lipoprotein gene-specific primers (MG-rPCR1) of this PCR were replaced with MG-16S rRNA primers (MG-rPCR2), as were the MS-16S rRNA primers (MS-rPCR), thus the study was pursued accordingly. All of the first 28 flocks, which were 100% positive by MG-ELISA, were MG-rPCR1 negative, whereas in the second part of the study, other 49 flocks, which were 87.8% MG seropositive, were found 42.9% positive by MG-rPCR2. In addition, 5 selected flocks from the first 28 were negative, whereas 7.4% of the 27 selected flocks from the second 49 were positive by MS-rPCR. Overall, 81 out of 432 MG-rPCR1-2 (18.7%) performed from 77 flocks, and 13 out of 187 MS-rPCRs (6.9%) in 32 flocks were determined as positive. ELISA results indicated that there could be significantly high false-positives in serological tests, thus results should not be relied upon one test system. Also, this study revealed that, for the confirmation of Mycoplasma-infected flocks in laboratories, rPCR is a reliable method as long as suitable primers are selected, and that MG and MS prevalence is considerably high in winter season. Keywords