Characterisation of staphylococci isolated from poultry

Coagulase-negative staphylococci (CoNS) as a significant etiological factor of laryngological infections: a review

This review article shows that coagulase-negative staphylococci (CoNS) are widely responsible for laryngological diseases. General characteristics of CoNS infections are shown in the introduction, and the pathogenicity in terms of virulence determinants, biofilm formation and genetic regulation mechanisms of these bacteria is presented in the first part of the paper to better display the virulence potential of staphylococci. The PubMed search keywords were as follows: CoNS and: nares infections, nasal polyps, rhinosinusitis, necrosing sinusitis, periprosthetic joint infection, pharyngitis, osteomyelitis of skull and neck bones, tonsillitis and recurrent tonsillitis. A list of laryngological infections and those related to skull and neck bones was presented with descriptions of the following diseases: rhinosinusitis, necrotizing sinusitis, nasal polyps, nares and nasal skin infections, periprosthetic joint infections, osteomyelitis, pharyngitis, and tonsillitis. Species identification and diagnostic problems challenging for diagnosticians are presented. Concluding remarks regarding the presence of CoNS in humans and their distribution, particularly under the effect of facilitating factors, are mentioned.

Bacterial chondronecrosis with osteomyelitis ('femoral head necrosis') of broiler chickens: a review

Bacterial chondronecrosis with osteomyelitis (BCO) in chickens was first reported in 1972 and is now recognized as an important cause of lameness in broiler chickens. Recent systematic studies of causes of lameness in birds reared in Northern Ireland have shown that it was the most common cause of lameness, being present in 17.3% of lame birds. Furthermore, it was also detected in birds presented as ''found dead''. Overall losses in male birds due to BCO were estimated to be 0.75% of all birds placed, which, in addition to welfare concerns, represents considerable economic loss. The disease has been seen in birds ranging from 14 to 70 days of age, but most cases occurred around 35 days old. It is most commonly caused by Staphylococcus aureus, but Escherichia coli, coagulase-negative staphylococci and Enterococcus spp. are sometimes involved, as are, rarely, other bacteria. The lesions are most commonly found associated with the growth plates of long bones, particularly the proximal growth plate of the femur and tibiotarsus, but other bones may also be affected. Since lesions were visible to the naked eye in only 40 to 67% of cases, histological examination is recommended where no lesions are visible macroscopically. As the lesion may be present in only one growth plate, and because histological examination is often not carried out, BCO is almost certainly underdiagnosed. The exact pathogenesis of the condition is unknown, but it is thought that adherence of blood-borne bacteria to exposed cartilage at the tips of metaphyseal blood vessels is fundamental. Under controlled experimental conditions, infection of birds with the immunosuppressive viruses chicken anaemia virus and infectious bursal disease virus increased the incidence of the disease, while restricting feed intake reduced the incidence of disease. S. aureus strains identical to, or closely related to, isolates recovered from naturally occurring cases of the disease (as determined by pulsed-field gel electrophoresis) have been recovered from fluff-debris in hatcheries, and also from the environment of breeding flocks, indicating that infection in the breeding farm and in the hatchery could be an important source of infection. It has also been shown that humans can carry poultry strains of S. aureus on their hands. There is a higher incidence of BCO in birds hatched from floor eggs. Thus, hygiene and management practice on breeder farms and in the hatchery may influence the occurrence of the disease. Bacteraemia is a prerequisite for BCO. Indeed, in some flocks suffering losses due to BCO, there are also losses due to staphylococcal septicaemia. Thus, appropriate treatment of affected flocks should reduce losses due to septicaemia. It should also reduce the occurrence of bacteraemia and the development of further cases of BCO. However, birds in which BCO has already developed, are unlikely to respond to treatment. Control of BCO by vaccination seems unlikely in the short term. Simple bacterins have not been effective and much basic research is needed to identify the important virulence factors. Furthermore, more than one type of bacterium is capable of causing the disease. Bacterial interference has been used successfully in humans and turkeys to prevent staphylococcal diseases, and warrants investigation for the prevention of BCO in chickens. This may have an advantage in that the interfering bacterium may also exclude some of the other bacteria that can cause BCO. The recent development of a disease model in which S. aureus is given by a natural route allows the potential for further investigation of the role of predisposing factors, and intervention strategies, including vaccination and bacterial interference, for the prevention of BCO.

Screening of genes encoding adhesion factors and biofilm formation in Staphylococcus aureus isolates from poultry

Staphylococcus aureus isolates recovered from poultry between 1970 and 1972 (90 old isolates) and in 2006 (81 recent isolates) were screened for the presence of bap, icaA and icaD genes associated with biofilm formation, and for bbp, cna, ebpS, eno, fib, fnbA, fnbB, clfA and clfB genes that encode microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). Most of the old isolates were collected from broiler breeders affected by staphylococcal tenosynovitis and arthritis, whilst nearly all recent isolates were derived from the nose and cloaca of healthy broilers. Ten recent isolates belonged to the animal-associated methicillin-resistant S. aureus (MRSA) ST398. All isolates were positive for clfA, clfB, eno and fnbA, and were negative for bap and bbp. All recent isolates were also positive for ebpS and cna, and all old isolates were positive for fib. The average number of genes encoding adhesins and biofilm-associated proteins in both groups was eight per isolate. All MRSA ST398 isolates in this study were positive for icaD, cna, ebpS, eno, fnbA, fnbB, clfA and clfB. No relevant differences were found between the presence of adhesin and biofilm formation genes in old and recent S. aureus isolates or in isolates from healthy compared with diseased chickens. From this study, there is no indication that the presence of these genes has changed over time and no specific association could be found between the presence of certain MSCRAMM or biofilm genes in poultry S. aureus isolates and the isolate's capacity to cause disease.

Antimicrobial resistance of old and recent Staphylococcus aureus isolates from poultry: first detection of livestock-associated methicillin-resistant strain ST398

The susceptibilities of 12 antimicrobial agents for two collections of Staphylococcus aureus, isolated in the 1970s and in 2006 from poultry, were determined. For eight antibiotics, the percentage of resistance was significantly higher in the recent isolates. Ten recent isolates were methicillin resistant and had spa types t011 and t567, belonging to multilocus sequence type 398. This is the first report of "livestock-associated" methicillin resistant S. aureus from healthy poultry.

Characterization of Staphylococcus aureus isolated from poultry meat in Spain

Ninety-six Staphylococcus aureus isolates from retail chicken carcasses in Spain were characterized using cultural and biochemical tests. The strains were phage typed with the international bacteriophage set for typing S. aureus of human origin. Eighty-eight (91.7%) strains were of the poultry ecovar. Strains of human ecovar were not found. These facts are congruent with findings of other authors. Ninety (93.7%) strains were phage typeable. Lysis by phages of Group III was the most frequent with 66 (68.7%) sensitive strains. Twenty-eight (29.2%) strains were sensitive at 100 routine test dilution (RTD) and only 16 (16.7%) at RTD. By using reversed phage typing, we managed to increase the number of phage typeable strains by 46 (47.9%). More than one S. aureus phage type was detected in 14 (35%) carcasses, which emphasizes the convenience of subtyping several S. aureus isolates from the same food sample in epidemiological studies. Two phage patterns (75/84 and 6/1030/ W57) were the most common. The S. aureus isolates were closely related, as 78 strains showed the most common or indistinguishable (<2 phage reaction differences) phage patterns.

Pathogenic staphylococci and staphylococcal infections in canaries

Staphylococcus aureus was isolated from six cases of bacterial infection in canaries, Staphylococcus hyicus from three and Staphylococcus intermedius from one case. Staphylococcus aureus was most often involved in outbreaks of septicaemia, with or without 'Megabacterium' proventriculitis. The other coccal species were mainly complicating disease caused by Atoxoplasma (Lankesterella), Chlamydia psittaci and canary pox.

Plasmid profiles as indicators of the source of contamination of Staphylococcus aureus endemic within poultry processing plants

A total of 530 strains of Staphylococcus aureus were isolated from the defeathering machinery of a chicken processing plant and from neck skin samples of carcasses at different stages of processing in two visits 4 weeks apart. Eleven different plasmid profiles were detected in the isolates, eight being common to both visits. The plasmid profiles of the strains forming the majority of the population on the freshly slaughtered birds were rarely present in the strains isolated from the pluckers (except at the entry to the first plucker) and were present in only a small proportion of the strains isolated from carcasses after plucking. However, the profiles from the strains isolated from the pluckers on both visits were different from those forming the majority of the population on the incoming birds but formed the major part of the carcass flora after plucking, suggesting that such strains were endemic. These strains were found as a small proportion of the isolates made from the incoming birds, suggesting that this was the route by which the endemic strains were introduced into the plant. Such endemic strains exhibited a clumping growth, even in liquid shake culture, which may have made it easier for them to become established on the pluckers and to resist cleaning and disinfection. This clumping phenotype was correlated with the presence of a 7.5-megadalton plasmid.

Staphylococcus aureus isolated from poultry in Australia. II. Epidemiology of strains associated with tenosynovitis

Bacteriophage typing of Staphylococcus aureus from different outbreaks of tenosynovitis in broiler breeder replacement chickens showed that, although a mixture of phage types was present on affected farms, there was a predominant phage type isolated from lesions of affected chickens. The predominant phage type isolated from chickens in different outbreaks was variable. The source of S. aureus associated with tenosynovitis appeared to be a resident population present on the skin.

Staphylococcus aureus isolated from poultry in Australia. I. Phage typing and cultural characteristics

The phage typing and cultural characteristics of 574 strains of S. aureus of poultry origin in Australia were examined. With the avian phage set of Shimizu (1979) it was possible to type 74.2% of strains. A number of significant variations in the phage typing patterns of Australian strains compared to those reported from Japan and Europe were observed. A lower proportion of Australian strains were of avian phage group I and a higher proportion of group III. A high proportion of strains were of mixed lytic groups. No locally isolated phages were able to increase significantly the percentage of typeable strains, although four local phages appeared to be of greater value for phage typing poultry strains of S. aureus than some other phages of the avian phage set. The international (human) phage set was of limited value in typing Australian strains of poultry origin although four strains were identified which were indistinguishable from strains of human origin. Using cultural characteristics of the strains in conjunction with phage typing, the Australian strains of S. aureus were assigned to one of three major groups and nine subgroups. A list of typing phages considered to be valuable for use on Australian poultry strains of S. aureus is given.

A comparison of methods used for testing staphylokinase (fibrinolysin) production in staphylococcus strains

Different nutrient bases, fibrinogen or heated plasma preparations and plasminogen sources were compared in tests for staphylokinase production by Staphylococcus aureus and other staphylococcal species. Media containing a nutrient base, bovine fibrin and dog plasma or serum proved to be more sensitive than the other substrates or combinations of substrates tested. Comparative testing on plates wih and without dog plasminogen or with plasmin inhibitors, was found to be necessary for the differentiation of staphylokinase from protease effects. Staphylokinases were produced by S. aureus, S. hyicus, S. simulans, S. sciuri and S. xylosus strains.

The use of a new phage set for typing poultry strains of Staphylococcus aureus obtained from seven countries

1. Eighty per cent of poultry strains of Staphylococcus aureus tested from French, Belgian, English, West German, Japanese and Argentinian sources were typable using a set of typing phages isolated in this laboratory. Strains from Bulgaria, however, with few exceptions were not typable with this phage set. 2. Strains isolated from lesions generally resembled those from apparently healthy poultry. 3. The existence of two distinct Staph. aureus biotypes on poultry was confirmed by isolates from six of the countries; one of these biotypes closely resembled Staph. aureus variety gallinae as described by Witte et al. (1977).

The identification of staphylococci in clinical and food microbiology laboratories

A comprehensive review of the methods which have been utilized for the identification of staphylococci is presented. Biochemical characteristics which have assisted in the primary isolation of staphylococci, such as pigmentation, hemolytic activity, the egg yolk phenomenon, and deoxyribonuclease and coagulase production, are also analyzed. The potential applicability of advanced techniques to identify staphylococci, such as the detection of enterotoxin production, base ratio analysis, cell wall analysis, phage typing, and serology, is discussed. The following procedures are recommended for routine use: Idnetification of Staphylococcus sp. (clinical laboratories): microscopic observation, catalase activity, coagulase production, lysostaphin sensitivity, and (optional) facultative growth in thioglycolate medium. Identification of Staphylococcus aureus (food laboratories): microscopic observation, catalase activity, coagulase production, thermonuclease production, and (optional) lysostaphin sensitivity.

Quantitative aspects of the Staphylococcus aureus flora of poultry

Important populations of Staphylococcus aureus were found to be present on the body surfaces of live poultry originating from flocks without history of staphylococcal disease. Their sized increased considerably until approximately the seventh week of life after which time they were maintained at equally high levels. Significant correlations were found between the populations recovered from superficial wash samples and skin-tissue samples. Similarly the numbers isolated from the nasal cavities were correlated with other surface counts. Low numbers were present in the intestinal tract. Birds with staphylococcal synovitis had higher numbers in all sampling regions. The counts were very high in subjects suffering from staphylococcal dermatitis. Higher rates of positive birds and higher numbers of staphylococci were detected with a whole body sampling method than with a nasal swab technique. The isolates obtained in this study belonged to the S. aureus biotype B which is associated with poultry and pigs.