New species and records of the mite genus Prolistrophorus (Acariformes: Listrophoridae) from rodents of the subfamily Sigmodontinae (Rodentia: Cricetidae)

Six fur-mite species of the genus Prolistrophorus Fain, 1970 (Acariformes: Listrophoridae) were recorded from Central and South American rodents of the subfamily Sigmodontinae (Rodentia: Cricetidae). Among them, Prolistrophorus (Aprolistrophorus) parabidentatus sp. nov. from Akodon azarae from Argentina and Prolistrophorus (Aprolistrophorus) tylomys sp. nov. from Tylomys nudicaudus from Guatemala are described as new for science. New hosts are recorded for the following species: Prolistrophorus (Prolistrophorus) grassii (Radford, 1954) from Zygodontomys brevicauda from Colombia, P. (P.) frontalis (Hirst, 1921) from Oligoryzomys sp. from Argentina, P. (P.) argentinus (Hirst, 1921) from Melanomys caliginosus, Akodon affinis from Colombia and Scapteromys aquaticus from Argentina, Prolistrophorus (Beprolistrophorus) hirstianus Fain, 1973 from Scapteromys aquaticus from Argentina.     

The genus Rhadinorhynchus (Acanthocephala: Rhadinorhynchidae) from marine fish in Australia with the description of four new species

Species of Rhadinorhynchus, collected from Australian waters were examined. Specimens of Rhadinorhynchus from Scorpis aequipinnis, Girella tricuspidata, Johnius australis and Grammatobothus polyophthalmus could not be identified further. New host and locality records are reported for R. bicircumspinus found in Trachurus declivis and Rexea solandri from the east coast of Tasmania; R. carangis found in Trachinotus bailonii and T. copperingi from Queensland and Western Australian coasts; R. polynemi from Queensland; R. seriolae found in Seriola lalandi from the east coast of Australia. An immature female specimen of R. johnstoni provided no additional data on the species. Rhadinorhynchus biformis sp. nov., described from Pelates quadrilineatus and a trumpeter from Moreton Bay, Queensland differs from all its congeners in the pattern of the trunk spines, a single field of numerous small spines ventro-laterally, overlapping with irregular rows and circles of larger spines extending posteriorly. Rhadinorhynchus pichelinae sp. nov. described from Upeneichthys vlamingi from Point Peron, Western Australia differs from all its congeners in having proboscis armature of 10 longitudinal rows of 24–28, usually 26–27 hooks up to 87 long and a single field of 21–24 irregular circles of spines on the anterior trunk, with the posterior circles incomplete dorsally. Rhadinorhynchus polydactyli sp. nov. described from Polydactylus sp. from Moreton Bay is differentiated from all congenerics by the elongated neck of the females and having a proboscis armature of up to 34 hooks in 10 longitudinal rows. Rhadinorhynchus pomatomi sp. nov. found in Pomotomus saltrix differs from its most similar congeners, those without dorsal trunk spines, in having a proboscis armature of 12–15 rows of 20–22 hooks up to 73.5–80.5 long. Rhadinorhynchus bicircumspinus, R. biformis, R. pichelinae, R. polydactyli and R. pomatomi are known only from Australian waters while R. carangis and R. seriolae are also known from Japanese waters, R. johnstoni from the western Pacific and R. polynemi from the Indian coast.     

Fur mites of the family Listrophoridae (Acariformes: Sarcoptoidea) associated with South American sigmodontine rodents (Cricetidae: Sigmodontinae)

Six species of 3 genera belonging to the fur mite family Listrophoridae were recorded on skins of South American rodents of the cricetid subfamily Sigmodontinae housed in the Bavarian State Collection of Zoology (Munich, Germany). Among them, Amlistrophorus geoxus sp. nov. from Geoxus valdivianus from Chile is described as a new for science, and males of Prolistrophorus amazonicus amazonicus Fain, 1971 are recorded for the first time. The full generic status for the subgenus Amlistrophorus of the genus Prolistrophorus proposed by Fain et al. (1996) is not supported, and Prolistrophorus musculinus Fain, 1973 stat. nov. (formerly a subspecies of P. amazonicus) from Mus musculus (Rodentia: Muridae) from Suriname is raised to species status. New hosts are recorded for the following species: Prolistrophorus argentinus (Hirst, 1921) from Holochilus brasiliensis and H. chacarius from Argentina, P. amazonicus from Calomys callosus from Argentina and Bolivia, C. laucha and C. musculinus from Argentina, P. akodon Fain and Lukoschus, 1982 from Akodon montensis from Argentina, P. nectomys Fain, 1971 from Nectomys palmipes from Peru and Melanomys caliginosus from Panama, and Sclerolistrophorus oxymycteris Fain, 1976 from Oryzomys laticeps from Brazil.     

A turbid plaque-forming mutant of phage P1 that cannot lysogenize Escherichia coli

The isolation and characterization of a new P1 mutant, called P1lyg, is described. P1lyg phage form turbid plaques, but are defective in ability to lysogenize Escherichia coli. The lyg^? allele cannot be rescued from a P1 cryptic lysogen, and data from three point crosses show that lyg maps near vir and c4. A lyg mutant does not prevent a lyg⁺ phage in the same cell from lysogenizing, but a lyg mutant cannot exist alone as a stable prophage even after mixed infection with lyg⁺.     

Effects of host diversity and the community composition of hard ticks (Ixodidae) on Babesia microti infection

Babesia microti (Apicomplexa, Piroplasmida) is one of the aetiological agents of human babesiosis, maintained in nature by complex zoonotic transmission cycles, involving small wild mammals as hosts and hard ticks (Ixodidae) as vectors. We previously reported that the B. microti strain commonly encountered among Microtus rodents in Poland is not zoonotic and that it is therefore most unlikely that it represents a risk to public health. Here, we analysed the contribution of four rodent species, Myodes glareolus, Apodemus flavicollis, Microtus arvalis, and Mi. oeconomus as hosts for two species of locally abundant ticks (Ixodes ricinus and Dermacentor reticulatus) and the rodent infective B. microti. Studies were carried out in the Mazury Lakes District of north-eastern Poland in 2005 and 2006. Infestation prevalence and abundance of both species of ticks (altogether 5674) collected from 781 rodent hosts, including 61 A. flavicollis, 495 My. glareolus, 99 Mi. arvalis, and 126 Mi. oeconomus from two different habitats, were determined. A. flavicollis and My. glareolus from the woodland habitat were more frequently infested with larvae and nymphs of I. ricinus ticks (96.7% and 87.9%, respectively) than the other species of hosts. In contrast, a higher percentage (>30%) of the other two species of rodents (Mi. arvalis, Mi. oeconomus) from fallow lands were infested with larvae and nymphs of D. reticulatus ticks (31.3% and 68.3%, respectively). Pronounced co-infestation rates (36.3%) of I. ricinus and D. reticulatus ticks (larvae and nymphs) were recorded on Mi. oeconomus. B. microti infections in blood samples of hosts and in ticks collected from hosts were examined by PCR, followed by sequence analysis. The prevalence of B. microti in hosts from the fallow lands (Mi. arvalis and Mi. oeconomus) was much higher than that in hosts from woodland (A. flavicollis and My. glareolus). However, the overall prevalence of B. microti in ticks collected from rodents was quite low, and varied from 3.4% for larvae to 4.8% for nymphs of I. ricinus and 11.8% for larvae to 4.0% for nymphs of D. reticulatus. The present study revealed for the first time the presence of B. microti DNA in partly engorged immature I. ricinus, but also in partly engorged larvae and nymphs of D. reticulatus. Furthermore, our results suggest widely differing roles of various rodent host species from two different habitats in maintaining zoonotic transmission of B. microti.     

Molecular study on three morphotypes of Demodex mites (Acarina: Demodicidae) from dogs

Canine demodicosis is a severe and highly prevalent dermatologic disease in dogs. Pet dogs can be affected by three recognized Demodex species that can produce clinical effects. In this paper, three morphological types of Demodex mites have been isolated from Spanish dogs. A complete morphobiometrical study of each one has been carried out. Morphological and biometrical studies revealed three closely related populations with some distinctive characteristics and could be identified as Demodex canis, Demodex injai, and Demodex sp. “cornei.” Furthermore, one population of D. canis from China, different populations of Demodex folliculorum from human skin (Spain and China), D. folliculorum from human eyelashes (Spain), and Demodex brevis from human skin (China) were considered to find out the level of variation between different species and geographical origin. The aim of the present study is to assess the usefulness of mitochondrial DNA molecular markers in establishing phylogenetic relationships and resolve taxonomic questions in Demodex mites. Molecular studies based on the amplification and sequencing of the 16S rDNA and cytochrome oxidase I mitochondrial genes did not show clear differences between the three morphotypes considered. Furthermore, phylogenetic relationships in Demodex mites were analyzed. The resulting phylogenetic trees show that Demodex species from dogs were gathered together, and populations of D. folliculorum from humans appear together in a different branch; however, D. brevis from humans seemed to be more distant. Our results show that cytochrome oxidase I region is a useful tool to solve different taxonomic questions at the species and population level and to infer phylogenetic relationships in Demodex species. However, 16S mitochondrial rDNA seems a good marker for comparisons at an interspecies level, but not at a population level in this group of mites. Furthermore, from genetic distance and divergence data, we would suggest that D. canis, D. injai, and Demodex sp. cornei are polymorphisms of the same species.     

Regulation and expression of human Fabs under the control of the Escherichia coli arabinose promoter,PBAD

Background: The l-arabinose operon from E. coli contains an inducible promoter P_BAD which has been extensively studied for the control of gene expression. P_BAD has a number of potential advantages over P_lac, and has been used successfully to promote high level expression of recombinant proteins. Objectives: The aim of this study was to investigate P_BAD as an alternative system to P_lac for the bacterial expression of recombinant Fabs. Study design: The promoter P_BAD from the E. coli arabinose operon araBAD and the gene encoding the regulator of this promoter, were cloned into the phagemid expression vector MCO1. Expression of human recombinant tetanus toxoid (TT) and c-erb B2 Fabs under the control of P_BAD was compared at two induction temperatures with the same Fabs produced under the control of P_lac. Results: Expression of TT and c-erb B2 Fabs under the control of P_BAD was comparable to Fab expression from P_lac. However, highly expressed TT Fab under the control of P_BAD was localised to the soluble periplasmic fraction whereas under the control of P_lac, there was greater leakage of Fab into the culture supernatant. In addition, Fab expression from P_BAD could be more tightly repressed than from P_lac. Conclusion: P_BAD is a useful and cheaply inducible alternative to the more commonly used P_lac for the rapid expression of soluble recombinant human antibody fragments.     

Parasitic infections of the African dwarf crocodile (Osteolaemus tetraspis) and the ornate Nile monitor (Varanus ornatus) from Nigeria

The parasitic infections of market derived Osteolaemus tetraspis from the rainforest and Varanus ornatus from locations in the savanna-mosaic and the rainforest of southern Nigeria were investigated. Parasites recovered from O. tetraspis included members of the Pentastomida, Trematoda and Nematoda. An undescribed pentastomid belonging to the family Sebekidae was recovered from O. tetraspis. The same parasite was also found to parasitize V. ornatus from the rainforest. Other parasites found in O. tetraspis were Pseudoneodiplostomum thomasi, Dujardinascaris sp. and larva of a Camallanus sp. Varanus ornatus from the rainforest and the derived savanna had some parasites including Duthiersia fimbriata, an unidentified pseudophyllidean cestode and Tanqua tiara in common. Cosmocerca ornata and Oswaldocruzia hoepplii were restricted to hosts from the derived savanna while the unidentified trematode occurred only in lizards from the rainforest. The unidentified pseudophyllidean cestode bears a close resemblance to Probothriocephalus, a cestode previously reported only from deep water teleosts. Pseudoneodiplostomum thomasi and Duthiersia fimbriata are new locality records for Nigeria.     

Comparative analysis of macrophage migration inhibitory factors (MIFs) from the parasitic nematode Onchocerca volvulus and the free-living nematode Caenorhabditis elegans

The macrophage migration inhibitory factors (MIFs) from the filarial parasite Onchocerca volvulus (OvMIF) were compared to the MIFs from the free-living nematode Caenorhabditis elegans (CeMIF) with respect to molecular, biochemical and immunological properties. Except for CeMIF-4, all other MIFs demonstrated tautomerase activity. Surprisingly, OvMIF-1 displayed oxidoreductase activity. The strongest immunostaining for OvMIF-1 was observed in the outer cellular covering of the adult worm body, the syncytial hypodermis; moderate immunostaining was observed in the uterine wall. The generation of a strong humoral immune response towards OvMIF-1 and reduced reactivity to OvMIF-2 was indicated by high IgG levels in patients infected with O. volvulus and cows infected with the closely related Onchocerca ochengi, both MIFs revealing identical amino acid sequences. Using Litomosoides sigmodontis-infected mice, a laboratory model for filarial infection, MIFs derived from the tissue-dwelling O. volvulus, the rodent gut-dwelling Strongyloides ratti and from free-living C. elegans were recognized, suggesting that L. sigmodontis MIF-specific IgM and IgG1 were produced during L. sigmodontis infection of mice and cross-reacted with all MIF proteins tested. Thus, MIF apparently functions as a target of B cell response during nematode infection, but in the natural Onchocerca-specific human and bovine infection, the induced antibodies can discriminate between MIFs derived from parasitic or free-living nematodes.     

Occurrence and molecular characterization of Hysterothylacium aduncum (Nematoda: Anisakidae) from Merlangius merlangus euxinus and Trachurus trachurus off the Turkish coast of Black Sea

A total of 286 larval forms of Hysterothylacium aduncum were collected from Merlangius merlangus euxinus and Trachurus trachurus captured at different sites of the Black Sea coast of Turkey. Prevalence of H. aduncum in M. merlangus euxinus and T. trachurus was 37.4 and 29.3 %, respectively. The fourth-stage larvae from M. merlangus euxinus and T. trachurus of H. aduncum were characterized genetically using a molecular approach. The ribosomal DNA (rDNA) internal transcribed spacer (ITS) region (ITS-1, 5.8S subunit, ITS-2) was amplified and sequenced. Two isolates of H. aduncum obtained from M. merlangus euxinus and T. trachurus in Black Sea showed a 100 % nucleotide similarity. Pairwise comparison between the entire ITS fragment including ITS-1, 5.8S, ITS-2 sequences of the H. adumcum isolates of M. merlangus euxinus and T. trachurus from Black Sea (Turkey, JX413596-JX413597) and other H. adumcum isolates from Baltic Sea (Poland, AJ937672), North Sea (Denmark, HM598666), Mediterranean Sea (Tunisia, HQ270427), Japan Sea (Japan, AB277826), Adriatic Sea (Croatia, JQ934878), East Greenland Sea, English Channel, Bay of Biscay, Adriatic Sea, and North Sea showed differences ranging from 0.1 to 0.7 %. With the present study, larvae of H. aduncum infecting M. merlangus euxinus and T. trachurus caught off the Black Sea, Turkey were characterized for the first time by sequencing of the ITS rDNA.     

Allele-Specific PCR Method Based on pncA and oxyR Sequences for Distinguishing Mycobacterium bovis from Mycobacterium tuberculosis: Intraspecific M. bovis pncA Sequence Polymorphism

An allele-specific amplification method based on two genetic polymorphisms to differentiate Mycobacterium tuberculosis from Mycobacterium bovis was tested. Based on the differences found at position 169 in the pncA genes from M. tuberculosis and M. bovis, a PCR system which was able to differentiate most of the 237 M. tuberculosis complex isolates tested in one of the two species was developed. All 121 M. tuberculosis strains showed the expected base (cytosine) at position 169. Most of the M. bovis isolates had a guanine at the cited position. Nevertheless, 18 of the 116 M. bovis isolates, all of them goat isolates, showed the pncA polymorphism specific to M. tuberculosis. These results suggest that goat M. bovis may be the nicotinamidase-missing link at the origin of the M. tuberculosis species. Based on the polymorphism found at position 285 in the oxyR gene, the same system was used to differentiate M. tuberculosis from M. bovis. In this case, DNAs from all 121 M. tuberculosis isolates had the expected base (guanine) at this position. In addition, all 116 M. bovis isolates, including those from goats, showed the identical polymorphism (adenine). The oxyR allele-specific amplification method can differentiate M. bovis from M. tuberculosis, is rapid (results can be obtained in less than 3 h), and is easy to perform.     

Comparison of Genotypes and Enterotoxin Genes Between Staphylococcus aureus Isolates from Blood and Nasal Colonizers in a Korean Hospital

In this study, we investigated the genetic background of 70 Staphylococcus aureus isolates (36 methicillin-resistant S. aureus [MRSA] and 34 methicillin-susceptible S. aureus [MSSA]) obtained from blood at a Korean tertiary-care hospital, using spa typing, multilocus sequence typing, and SCCmec typing. In addition, the prevalence of enterotoxin (sea, seb, sec, sed, see, seg, seh, sei, and sek), tst, and pvl genes among the samples was assessed via polymerase chain reaction, and the results were compared with those of 95 isolates of S. aureus obtained from nasal swabs. All MRSA isolates from blood, except one, belonged to three major clones: sequence type (ST)5-MRSA-II, ST72-MRSA-II (or IVA), and ST239-MRSA-III, among which ST5-MRSA-II was the predominant clone. The prevalence of enterotoxin genes in the S. aureus isolates obtained from blood differed significantly from those from the nasal swabs for the sea, seb, sec, and seh gene. In particular, the seb and sec genes were detected exclusively in the MRSA isolates of ST5 or spa-CC002, thereby suggesting the co-adaptation of virulence genes with the genetic background and their contribution to biological fitness.     

Species-specific antibody responses to the recombinant 53-kilodalton excretory and secretory proteins in mice infected with Trichinella spp

The 53-kDa proteins in larval excretory and secretory (E-S) products were expressed from five Trichinella species (T. spiralis, T. britovi, T. nativa, T. pseudospiralis, and T. papuae), using the Escherichia coli expression system, and the antibody responses to the 53-kDa recombinant proteins in mice infected with Trichinella spp. were analyzed by Western blotting. The 53-kDa protein is conserved among the five Trichinella species, with >60% similarity in amino acid sequences. The 53-kDa recombinant proteins of T. spiralis and T. pseudospiralis reacted to sera from mice infected with T. spiralis and T. pseudospiralis at 8 days postinfection (p.i.), respectively. An antibody against the 53-kDa recombinant protein of T. spiralis recognized the 53-kDa protein in the crude extracts from adult worms and 30-day p.i. muscle larvae and E-S products from muscle larvae of T. spiralis but did not recognize any proteins from T. pseudospiralis. The sera from the mice infected with T. spiralis strongly reacted with the 53-kDa recombinant protein of T. spiralis but did not react with the 53-kDa recombinant proteins of T. britovi, T. nativa, T. pseudospiralis, and T. papuae. Similarly, the sera from mice infected with T. britovi, T. nativa, T. pseudospiralis, or T. papuae strongly reacted with the 53-kDa recombinant proteins of T. britovi, T. nativa, T. pseudospiralis, or T. papuae, respectively. These results showed that the 53-kDa recombinant proteins provide early and species-specific antibody responses in mice infected with Trichinella spp.     

Antigenic Studies of Oral and Nonoral Black-Pigmented Bacteroides Strains

Antigens of several oral and nonoral strains of Bacteroides asaccharolyticus (proposed classification of oral B. asaccharolyticus, Bacteroides gingivalis), Bacteroides melaninogenicus subsp. intermedius, B. melaninogenicus subsp. melaninogenicus, and B. melaninogenicus subsp. levii were identified in soluble preparations obtained by sonication, autoclaving, and NaOH treatment of whole bacterial cells. The sonicate preparations contained the most complete representation of soluble antigens using antisera to the whole organism in gel precipitation tests. Among strains of B. melaninogenicus subsp. intermedius many common antigens were detected, and no consistent antigenic differences were seen between strains from oral and nonoral sites. None of the antigens of B. melaninogenicus subsp. intermedius reacted with sera raised to several strains of oral or nonoral B. asaccharolyticus, nor did antigens prepared from the latter strains react with antisera to B. melaninogenicus subsp. intermedius. At least one common antigen was shared by strains of B. melaninogenicus subsp. intermedius and strains of B. melaninogenicus subsp. melaninogenicus; however, subspecies-specific antigens were also found. Antigens from and antisera to oral and nonoral strains of B. asaccharolyticus did not react with sera to and antigens from B. melaninogenicus subsp. melaninogenicus. Strains of B. asaccharolyticus isolated from the oral cavity were antigenically distinct from strains of B. asaccharolyticus obtained from nonoral sites and lesions. This lack of cross-reactivity between the oral and nonoral strains of B. asaccharolyticus together with recent findings of marked genetic differences between oral and nonoral strains of B. asaccharolyticus suggest that these groups of organisms may represent different species.     

First data on the genetic diversity of avian haemosporidians in China: cytochrome b lineages of the genera Plasmodium and Haemoproteus (Haemosporida) from Gansu Province

A total of 76 birds belonging to 23 species and 14 families was examined for the presence of Plasmodium spp. and Haemoproteus spp. Birds were trapped at four localities in Gansu Province, China, in June–July 2011. DNA was isolated from blood samples and parasite detection, and identification was based on PCR assays and sequences of 479 bp of cyt b gene. The total prevalence of haemosporidians was 21.0 %. Haemoproteus spp. were detected in 14 birds (prevalence 18.4 %). The lineage CYAPIC1 from Cyanopica cyanus, Parus major, Passer montanus and Pyrrhocorax pyrrhocorax was new; it is genetically distinct and probably represents a new species of the genus Haemoproteus. Three lineages represented known species: RBS4 (from Lanius tephronotus), a lineage of Haemoproteus lanii; COLL2 (from Turdus mupinensis), a lineage of Haemoproteus pallidus and TURDUS2 (from Turdus rubrocanus), a lineage of Haemoproteus minutus. The lineage RBS5 (from Lanius cristatus and L. tephronotus) differs by 1.4 % from RBS4 and probably represents an intraspecific entity of H. lanii. The lineages TUCHR1 (recorded from T. mupinensis), WW1 (recorded from Upupa epops) and YWT2 (recorded from Motacilla flava) have not been linked to any known species for the moment. Only one bird was positive for Plasmodium (prevalence 1.4 %), i.e. P. major infected with the lineage GRW4 of Plasmodium relictum. The latter lineage has been considered by previous studies as typical for migratory birds and having transmission in tropical areas only; its record in a sedentary bird in China suggests its transmission in temperate latitudes.     

New records and new species of mites of the subfamily Harpirhynchinae (Acariformes: Harpirhynchidae) infesting birds in Manitoba, Canada

Five new species and one new genus of the subfamily Harpirhynchinae (Acariformes: Harpirhynchidae) are described from birds in Canada: Harpyrhynchoides heatherae sp. nov. from Junco hyemalis (Passeriformes: Emberizidae), H. botaurus sp. nov. from Botaurus lentiginosus (Pelecaniformes: Ardeidae), H. phalaropus sp. nov. from Phalaropus lobatus (Charadriiformes: Scolopacidae), Neharpyrhynchus loxia sp. nov. from Loxia curvirostra (Passeriformes: Fringillidae), and Fainharpirhynchus contopus gen. nov., sp. nov. from Contopus cooperi (Passeriformes: Tyrannidae). Additionally, 3 species were recorded in Canada (Manitoba) for the first time: Harpyrhynchoides tracheatus (Fritsch, 1954) from Buteo jamaicensis (Accipitriformes: Accipitridae) (new host), H. modestus (Fain, 1976) from Columba livia (Columbiformes: Columbidae) (new host), and Neharpyrhynchus pilirostris (Berlese et Trouessart, 1889) from Passer domesticus (Passeriformes: Passeridae).     

Bartonella tamiae sp. nov., a newly recognized pathogen isolated from three human patients from Thailand

Three strains of a novel Bartonella species (Bartonella tamiae) were isolated from human patients from Thailand. Sequence analysis of six chromosomal regions (16S rRNA, gltA, groEL, ftsZ, rpoB, and the intergenic spacer region) and phenotypical analysis supported the similarity of the three strains and placed them within the genus Bartonella separately from previously described species.     

Development of a PCR technique specific for Demodex injai in biological specimens

The identification of Demodex injai as a second Demodex species of dog opened new questions and challenges in the understanding on the Demodex–host relationships. In this paper, we describe the development of a conventional PCR technique based on published genome sequences of D. injai from GenBank that specifically detects DNA from D. injai. This technique amplifies a 238-bp fragment corresponding to a region of the mitochondrial 16S rDNA of D. injai. The PCR was positive in DNA samples obtained from mites identified morphologically as D. injai, which served as positive controls, as well as in samples from three cases of demodicosis associated with proliferation of mites identified as D. injai. Furthermore, the PCR was positive in 2 out of 19 healthy dogs. Samples of Demodex canis and Demodex folliculorum were consistently negative. Skin samples from seven dogs with generalized demodicosis caused by D. canis were all negative in the D. injai-specific PCR, demonstrating that in generalized canine demodicosis, mite proliferation is species-specific. This technique can be a useful tool in the diagnosis and in epidemiologic and pathogenic studies.     

Molecular types and genetic profiles of Staphylococcus aureus strains isolated from bovine intramammary infections and extramammary sites

Staphylococcus aureus isolates collected from sites of intramammary infection during a 10-month period and from extramammary sites (dairy cow teat skin, teat canals, and skin lesions; milking liners; and hands and nostrils of milking personnel) at two separately managed Finnish dairy herd establishments were analyzed to study the sources and reservoirs of bovine S. aureus intramammary infection. Selected isolates were subjected to pulsed-field gel electrophoresis (PFGE) typing and PCR analysis for genes encoding hemolysins (hla to hlg), leukocidins (lukED and lukM), superantigens (sea, sec, sed, seg to seo, seu, and tst), adhesins (fnbA and fnbB), and penicillin and methicillin resistance (blaZ and mecA). S. aureus was found throughout the herds in 94% of the cows. Nine PFGE types were found, with the herds each having their own predominant type and sharing one type. The degree of diversity of PFGE types in herd II, which integrated foreign heifers, was higher than that in herd I. For both herds, the majority of the PFGE-typed isolates both from milk and from extramammary sites represented the predominant PFGE types. In isolates from herd I, the most prevalent genes were hla-hlg, lukED, and fnbA; in those from herd II, they were hla, hld, hlg, lukED, and fnbA. The other genes were pulsotype linked within the herds. The predominant PFGE types carried both fnbA and fnbB; only fnbA was detected in the other PFGE types. No connection between specific virulence genes and the origins of isolates was found. The results suggest that for the two herds, most S. aureus isolates from extramammary sites were indistinguishable from the isolates infecting the mammary gland and that those sites can thus act as origins and reservoirs of intramammary infections. However, contamination in the opposite direction cannot be excluded.