Comparison of polymerase chain reaction and conventional culture for the detection of legionellas in hospital water samples

A detection system for Legionella spp. based on the polymerase chain reaction (PCR) was used to assess the diagnostic value of PCR for the surveillance of contamination of man-made water systems by legionellas. A previously-published primer system was chosen to amplify a fragment of the 5S-ribosomal gene of Legionella spp. A total of 78 water samples from various sources were examined by PCR and culture on MWY Legionella selective agar. Fifty-seven of 78 water samples were positive by both test systems (73%), nine were positive by PCR only (11.5%), another nine were positive by culture but negative by PCR (11.5%), and three were negative by both techniques (3.8%). The PCR was inhibited when large amounts of rust were present in the samples. Culture failed to detect legionellas in samples that contained large numbers of other bacteria capable of overgrowing the legionellas. These results show that PCR is a rapid and sensitive technique for the detection of legionella contamination in water samples and that PCR and culture complement each other in monitoring of environmental water samples.     

Aerobic oral and rectal bacteria of free-ranging Steller sea lion pups and juveniles (Eumetopias jubatus) in Alaska

Bacteriologic cultures from oral, rectal, and lesion samples from free-ranging Steller sea lion (SSL, Eumetopias jubatus) pups and juveniles in Alaska (2001-2005) were examined to determine frequency of infection by a specific subset of common and pathogenic aerobic bacteria. Associations between isolated bacteria and age, sex, body condition, location, and sampling season were investigated. Salmonella spp. isolates were further evaluated to determine spatial clustering (n=48) and to identify serovars (n=13) and antimicrobial susceptibility patterns (n=11). We sampled 356 SSL pups (n=272) and juveniles (n=84), and identified 988 isolates of 13 bacterial genera of specific interest. Pasteurella spp. (43.8%), beta-hemolytic Streptococcus spp. (30.6%), and Mannheimia spp. (18.2%) were the most commonly isolated oral bacteria (n=499 isolates), whereas Escherichia coli (47.6%), beta-hemolytic E. coli (32.4%), Salmonella spp. (10.4%), and Campylobacter spp. (7.8%) were the most frequently isolated rectal bacteria (n=460 isolates). Salmonella was most commonly found in pups from western stocks and in samples collected during fall/winter seasons. A significant Salmonella cluster was detected at the Perry Island haulout. Five serovars were isolated: Enteritidis, Infantis, Newport, Reading, and Stanley. Pulsed-field gel electrophoresis provided evidence that Salmonella isolates were most likely being maintained within the SSL population in Alaska.     

Occurrence of Thermotolerant Campylobacter spp. on Eggshells: a Missing Link for Food-Borne Infections?

We analyzed the prevalence of thermotolerant Campylobacter spp. compared that of to Salmonella spp. in raw yolk and on eggshells. A total of 2,710 eggs were investigated for each bacterium. Viable bacteria were found in 4.1% (Campylobacter spp.) and 1.1% (Salmonella spp.) of the eggshell samples, whereas the egg yolk samples were negative for both bacteria.     

降雨对秦皇岛西浴场细菌总数和可培养菌群组成的影响

【目的】研究降雨条件对浴场细菌总数和优势菌群组成的影响。【方法】2014年8月强降雨前后采集秦皇岛西浴场3个站位的海水样品,采用荧光显微镜计数法和平板计数法分别对细菌总数和可培养细菌总数进行计数;对群落结构组成进行分析,并对可培养细菌进行鉴定。【结果】雨前3个站位细菌总数和可培养细菌总数平均值分别为5.6×10~9 CFU/L和8.3×10~7 CFU/L,雨后分别为9.2×109 CFU/L和2.1×10~8 CFU/L。在可培养菌群中,变形菌门(Proteobacteria,雨前占80%,雨后占73%)是主要的微生物类群,其次为拟杆菌门(Bacteroides,雨前占12%,雨后占13%)、厚壁菌门(Firmicutes,雨前占7%,雨后占11%)等;肠杆菌属(Enterobacter spp.,21株)、海杆菌属(Marinobacter spp.,13株)、弓形菌属(Arcobacter spp.,13株)、假单胞菌属(Pseudomonas spp.,10株)、芽孢杆菌属(Bacillus spp.,10株)和弧菌属(Vibrio spp.,6株)为雨前可培养细菌优势属,而雨后可培养细菌优势属为肠杆菌属(22株)、海杆菌属(21株)、芽孢杆菌属(14株)、不动杆菌属(Acinetobacter spp.,11株)、假单胞菌属(9株)和弓形菌属(5株)等。【结论】降雨对细菌总数有显著的影响,同时降雨后浴场微生物群落结构发生了改变。     

Evaluation of bio-aerosols at an animal feed manufacturing industry: A case study

Both total and biological particles (totalculturable bacteria, Gram negative bacteria,mold and actinomycetes) were measured at ananimal feed manufacturing industry. Suspendedparticle concentration ranged from 1.72 to2.3 mg m^–3 with a mean value of1.97 mg m^–3. Airborne microorganisms weredetected in lower concentrations than thoseassociated with suspended dust andfeed-materials. Bacterial concentrations weretwo to three times higher than concentrationsof mold and actinomycetes. Bacterialconcentrations averaged4.86 × 10³ cfu m^–3; 2.6 × 10⁴cfu m^–3 and 3.96 × 10⁷ cfu g^–1 inair, associated with suspended dust andfeed-materials, respectively, whereas moldconcentrations averaged 7.33 × 10²cfu m^–3; 1.97 × 10³ cfu m^–3 and7 × 10⁵ cfu g^–1 of the correspondingenvironments, respectively. Enterobacterspp and Klebsiella spp were the mostabundant Gram negative bacteria, whereas Bacillus species. were the most dominant Grampositive bacteria. Aspergllius niger,other Aspergillus species and Penicillium were the dominant mold isolates.Acremonium was only detected in feedmaterials, whereas Aspergillus fumigatuswas only detected in air. The animal feedindustry environment has a significantbio-contamination and many of microorganismsimplicated in respiratory problems weredetected in this environment.     

Efficacy of a commercial polymerase chain reaction-based assay for detection of Salmonella spp. in animal feeds

Salmonellosis is a cyclic problem in the food industry, to which animal feed has been contributory. Current conventional methods of Salmonella spp. detection require 96 h for detection and confirmation. With modern and just-in-time production schedules, a 96-h hold represents a significant expense in storage and decontamination. The commercially available assay, 'BAX for Screening/Salmonella' (BAX), is based on the principle of the polymerase chain reaction and may represent a significant decrease in assay time. Seven fresh feed formulations, two fresh feed ingredients, seven stored feeds and two stored feed ingredients were artificially contaminated with a primary poultry isolate of Salmonella typhimurium and analysed by conventional and BAX methodology. The results of BAX agreed with conventional plating results for 16 of 18 samples spiked with 1200 cfu 10 g(-1) of feed and 13 of 18 samples spiked with 40 cfu 10 g(-1) of feed. Indigenous Salmonella spp. were detected in five of eight samples of poultry diets by conventional methods. With BAX, Salmonella spp. could not be detected in any of the samples after only 7 h of enrichment but could be detected in two dietary samples after 13 h of enrichment and four dietary samples after 24 h of enrichment. Specific sequences of salmonella DNA that were extracted from poultry diets could be detected with BAX.     

HEMOGLOBIN AS A CAPTURE AGENT FOR LIPOPOLYSACCHARIDE ANTIGENS IN THE ENZYME IMMUNOASSAY OF GRAM NEGATIVE BACTERIA

Abstract The affinity of hemoglobin for lipopolysaccharides (LPS) was exploited in its use as an inexpensive capture agent for LPS antigens in the enzyme immunoassay (EIA) of Gram negative bacteria. Two EIA formats were examined. In one, the macroporous solid phase Polymacron ^TM coated with hemoglobin was used to capture cholate-heat extracted LPS antigens from broth cultures of representative Gram negative bacteria, including different Salmonella serotypes, which were then detected immunoenzymatically using specific antibodies. This provided a rapid, simple and inexpensive dot blot assay for these bacteria which minimized the requirement for laboratory equipment. In another format, a microtiter plate EIA was developed in which cholate-heat extracted Salmonella . LPS antigens were captured in hemoglobin-coated wells. The microtiter plate format is automatable and will therefore be useful in laboratories with high sample throughputs. While most of the results reported here focus on the detection of Salmonella spp., we also demonstrate the applicability of this system in the assay of Escherichia coli O157 LPS antigens .     

Microbiological quality of wheat flour consumed in Morocco

Cereal products (soft and hard wheat) are a basic staple food in the Moroccan diet. A total of 60 samples of two types of wheat flours used for human consumption were collected; 30 samples among this collection were obtained from various households using Moroccan varieties of wheat produced in traditional flour mills. The rest of the samples were purchased from retail wheat flour sources in the Rabat and Sale city markets. Standard plate counts (SPC), total and faecal coliforms, Clostridium, Salmonella spp., Shigella spp., Staphylococcus aureus, Listeria monocytogenes, yeast, lactic acid bacteria, and molds, were carried out to assess the microbiological quality of wheat flour. Microbiological interpretation of the criteria was performed according to standards implemented by the Codex Alimentarius Commission. Most frequent counts, in traditional and industrial wheat flour, were total aerobic mesophilic bacteria with an average 4 × 104 and 2.5 × 104 cfu/g, respectively. The results showed higher coliform and fungi counts in house than in commercial samples. Pathogenic flora as Salmonella spp., Shigella spp., S. aureus, L. monocytogenes, and Clostridium were not detected in all investigated samples. Bacterial strains isolated from both flours belong to the following genera: Enterobacter spp., Serratia spp., Klebsiella spp., Pantoea spp., Leclercia spp., Proteus spp. The most frequent genus of the investigated isolates was Aspergillus (81 %). Microbial counts were lower than the limit laid down in the Codex Alimentarius, attributing to these flours a satisfactory microbiological quality.     

Biofilm formation in an ice cream plant

The sites of biofilm formation in an ice cream plant were investigated by sampling both the production line and the environment. Experiments were carried out twice within a 20-day period. First, stainless steel coupons were fixed to surfaces adjacent to food contact surfaces, the floor drains and the doormat. They were taken for the analysis of biofilm at three different production stages. Then, biofilm forming bacteria were␣enumerated and also presence of Listeria monocytogenes was monitored. Biofilm forming isolates were selected on the basis of colony morphology and Gram’s reaction; Gram negative cocci and rod, Gram positive cocci and spore forming isolates were identified. Most of the biofilm formations were seen on the conveyor belt of a packaging machine 8 h after the beginning of the production, 6.5 × 10³ cfu cm⁻². Most of the Gram negative bacteria identified belong to Enterobacteriaceae family such as Proteus, Enterobacter, Citrobacter, Shigella, Escherichia, Edwardsiella. The other Gram negative microflora included Aeromonas, Plesiomonas, Moraxella, Pseudomonas or Alcaligenes spp. were also isolated. Gram positive microflora of the ice cream plant included Staphyloccus, Bacillus, Listeria and lactic acid bacteria such as Streptococcus, Leuconostoc or Pediococcus spp. The results from this study highlighted the problems of spread of pathogens like Listeria and Shigella and spoilage bacteria. In the development of cleaning and disinfection procedures in ice cream plants, an awareness of these biofilm-forming bacteria is essential for the ice cream plants.     

Control of foodborne pathogens during sufu fermentation and aging

Control of the foodborne pathogens Escherichia coli O157:H7, Salmonella typhimurium, Staphylococcus aureus, and Listeria monocytogenes during sufu fermentation was evaluated. Before fermentation, pathogens were inoculated onto tofu (substrate for sufu) at 5 log cfu/g or 3 log cfu/g, and starter culture (Actinomucor elegans) was inoculated at 3 log cfu/g. After 2 days of fermentation at 30 degrees C, the four pathogens reached 7 to 9 log cfu/g, and the mold count reached 6 to 7 log cfu/g. After fermentation, sufu samples were aged in a solution of 10% alcohol + 12% NaCl. After 1 month of aging, the total bacterial count was 6 to 7 log cfu/g, but all foodborne pathogens and mold were reduced to nondetectable levels. The total bacterial count decreased after aging for 2 months and 3 months, but the differences were not significant (P > 0.05) compared with the count after 1 month. Microorganism in experimental sufu from different aging periods and in commercial sufu were compared. A total of 270 isolates were purified and identified by the BBL Crystal Identification System. From the experimental sufu samples, 49 Bacillus spp. (20.4%), 167 Enterococcus spp. (69.6%), 6 Shewanella putrefaciens (2.4%), and 18 miscellaneous gram-negative bacilli (7.5%) were identified. From commercial sufu samples, 17 Bacillus spp. (56.7%), 2 Enterococcus durans (6.7%), 5 miscellaneous gram-negative bacilli (16.7%), 5 Corynbacterium aquaticum (16.7%), and 1 Shewanella putrefaciens (3.3%) were obtained. Although the longer aging period did not significantly decrease the total bacterial count, it may help in the development of sufu flavor. This study showed that sufu fermentation and aging can control common foodborne pathogens, so sufu is a safe product even though its preparation does not include pasteurization.     

Treatment of sanitary-important bacteria by bacteriocin substance V24 in cattle dung water

Quantification of sanitary-important bacteria (e.g. Enterobacteriaceae), as well as indicators of environmental contamination, was assessed in samples of cattle dung from 25 cattle farms in 15 north-eastern Slovakia districts. The inhibitory effect of crude bacteriocin extract CBE V24 from Enterococcus faecalis V24 against Listeria monocytogenes Ohio and Yersinia enterocolitica YE85 was examined in cattle dung water with the aim of finding a new way of eliminating the health risk of the animal slurry. The following bacterial groups were quantified: Salmonella spp., Shigella-like spp. , Proteus spp., Enterobacter spp., Citrobacter spp., Pseudomonas spp. , Escherichia coli, Listeria spp., staphylococci, streptococci and enterococci (the average count ranged from 102 up to 104 cfu ml-1). Antagonistic effect of the crude bacteriocin from Enterococcus faecalis V24 in the range of 100-600 Arbitrary units per ml (AU ml-1) was shown against the following bacteria: Enterobacter cloacae, Ent. asburiae, Proteus spp., Salmonella spp., Acinetobacter lwoffi, L. monocytogenes as well as Y. enterocolitica YE85. During tests performed to study the inhibitory effect of the crude bacteriocin CBE V24 (concentration 800, 1600 AU ml-1) against L. monocytogenes Ohio and Y. enterocolitica YE85 in experimentally contaminated cattle dung, a reduction of 2.03 and 1.44 log cfu ml-1, respectively, was already noted after 1 h after crude bacteriocin CBE V24 addition.     

Bacterial concentrations in bedding and their association with dairy cow hygiene and milk quality

Comparison of bacterial counts (BCs) among common bedding types used for dairy cows, including straw, is needed. There is concern that the microbial content of organic bedding is elevated and presents risks for dairy cow udder health and milk quality. The objectives of this study were to investigate: (1) % DM and BCs (Streptococcus spp., all gram-negatives and specifically Klebsiella spp.) in different types of bedding sampled, and to investigate housing and farm management factors associated with % DM and BCs; (2) if bedding type was associated with hygiene of cow body parts (lower-legs, udder, upper-legs and flank) and housing and management factors associated with hygiene and (3) bedding types associated with higher BCs in cow milk at the farm level and bulk tank milk and management factors that were associated with highest BCs. Seventy farms (44 free-stall and 26 tie-stall) in Ontario, Canada were visited 3 times, 7 days apart from October 2014 to February 2015. At each visit, composite samples of unused and used bedding were collected for % DM determination and bacterial culture. Used bedding samples were collected from the back third of selected stalls. Data were analyzed using multivariable linear mixed models. Bedding classification for each farm were: new sand (n = 12), straw and other dry forage (n = 33), wood products (shavings, sawdust; n = 17) and recycled manure solids (RMSs)-compost, digestate (n = 8). In used bedding, across all bedding samples, sand was driest, compared to straw and wood, and RMS; higher % DM was associated with lower Streptococcus spp. count. Streptococcus spp. and all Gram-negative bacteria counts increased with increasing days since additional bedding was added. Gram-negative bacteria counts in used bedding varied with type: RMS = 16.3 ln colony-forming units (cfu)/mL, straw = 13.8 ln cfu/mL, new sand = 13.5 ln cfu/mL, and wood = 10.3 ln cfu/mL. Klebsiella spp. counts in used bedding were lower for wood products (5.9 ln cfu/mL) compared to all other bedding types. Mean cow SCC tended to be higher on farms with narrower stalls. Farms with mattress-based stalls had a higher prevalence of cows with dirty udders compared to those using a deep bedding system (often inorganic sand). Wider stalls were associated with lower bulk milk bacteria count. Lower % DM of used bedding was associated with higher bulk milk bacteria count. In conclusion, bedding management may have a profound impact on milk quality, bacterial concentrations in the bedding substrates, and cow hygiene.     

Climate patterns governing the presence and permanence of salmonellae in coastal areas of Bahia de Todos Santos, Mexico

Despite the importance of salmonellae as one of the major causes of food-borne infections worldwide, data regarding the presence of these organisms in the environment are limited. We investigated the presence of Salmonella spp. in Bahia de Todos Santos (Baja California, Mexico) and evaluated the environmental factors that affect the occurrence of Salmonella spp. in this arid region. A total of 1,331 samples collected from 21 sites along the coast during a period of 3 years were analyzed for Salmonella spp. Geographical and seasonal distribution of Salmonella spp. was evaluated in association with environmental parameters and with human infections in the area. The incidence of Salmonella bacteria throughout the study was 4.8%, with the highest incidence detected in wastewater (16.2%), followed by stream water (10.6%), mollusks (7.4%), and seawater (2.3%). Twenty different serotypes were identified among the 64 Salmonella isolates. The dominant serotype was Typhimurium (23.4%), followed by Vejle (6.2%). The presence of Salmonella spp. in coastal areas was mostly confined to rainy periods and areas of stream discharges, and runoff was identified as the predominant factor influencing the transport of Salmonella bacteria from source points to the sea via streams. Isolation of Salmonella spp. was negatively and significantly associated with temperature, probably because of the effect of solar radiation in the decline of permanence of Salmonella bacteria. Conversely, human infections prevailed during the warmest months and were negatively correlated with the presence of Salmonella spp. in the marine environment.     

Isolation of Salmonella spp. from liquid and solid excreta prior to and following ensilage in ten swine farms located in central Mexico

A study was carried out to define selected bacteriological characteristics of residues from 10 swine farms, 5 with or without prior clinical enteric disease (PCED) and to determine the effect of ensilage on the bacteria present in the solid fraction. At each farm, samples were taken from the sedimentation basin (SB), the solid fraction (SF), and the liquid fraction (LF). For each sample, CFU/g for enteric bacteria were quantified; Salmonella spp. were isolated and typified. Solid phase samples from each farm were used to prepare the ensilage, with a mixture of solids (80%), sorghum (12%) and molasses (8%). The quantity of enteric bacteria was significantly greater in farms without PCED (P < 0.05). Salmonella enterica were isolated from 8/10 of the farms with and without PCED; in 8 from SB; in 6 from LF; and in 5 from SF. Enteric bacteria were not isolated from silage, therefore, ensilage may be an alternative treatment for excreta that allows the elimination of pathogens such as Salmonella spp.     

Detection of Legionella species in sewage and ocean water by polymerase chain reaction, direct fluorescent-antibody, and plate culture methods.

Legionella spp. are ubiquitous in most environmental water sources; however, sewage treatment plants have not been examined as potential environmental reservoirs for these bacteria. This study used polymerase chain reaction, direct fluorescent-antibody staining, and culture methods to examine raw and treated sewage, ocean-receiving waters, and nearshore coastal environments for the presence of Legionella pneumophila and other Legionella spp. The study concluded that Legionella spp. are present in all phases of sewage treatment and that population numbers do not significantly decline through the treatment process. Ocean-receiving waters located 5 miles offshore, where the treated sewage is discharged, were found to contain Legionella spp., but ocean water between the discharge site and coastal bathing beaches was negative. This suggests that the Legionella spp. from the ocean discharge site were not reaching the nearshore beach waters. A flood control channel and river that entered the ocean were found to contain Legionella spp., and a nearby beach swimming area was also found to be positive, suggesting that land runoff from the flood control channel and river were the source of the Legionella spp. in the beach water samples that tested positive.     

Microbiology of Nigerian Palm Wine with Particular Reference to Bacteria

The bacteria isolated from samples of wine produced by the fermentation of the saps of Elaeis and Raphia palms were identified as Micrococcus, Leuconostoc, Streptococcus, Lactobacillus, Acetobacter, Serratia, Aerobacter (Klebsiella), Bacillus, Zymomonas and Brevibacterium . The organisms occurring most frequently belonged to the first 5 genera. The change from c. pH 7 to c. pH 4.5 during fermentation appeared to be due to lactic acid bacteria and/or certain Gram negative bacteria, e.g. Serratia and Aerobacter (Klebsiella) spp. From about the 3rd day onwards, Acetobacter spp. were recovered.     

Retrospective and longitudinal study of salmonellosis in captive wildlife in Trinidad

Morbidity and mortality of captive wildlife at the Emperor Valley Zoo, Trinidad from 1993 to 1996 were analysed to determine involvement of Salmonella spp. A 6 mo longitudinal study was conducted to determine the frequency of isolation of Salmonella spp. from apparently healthy, sick and dead wild mammals, birds, and reptiles. The antibiograms of Salmonella isolates were determined using the disc diffusion method. Fecal samples randomly selected from animal enclosures and cloacal swabs of snakes were cultured for Salmonella spp. following enrichment in tetrathionate and selenite cystine broths. For the 1993-96 period, Salmonella spp. was implicated in 17 (12%) of 141 sick or dead animals and the predominant serotype was S. typhimurium. During the 6 mo prospective study in a mean animal population of 1,186, there were 20 (2%) and 14 (1%) animals that were sick and died respectively; Salmonella spp. was implicated in only one mortality. Overall, of 1,012 samples from apparently healthy wildlife cultured, 66 (7%) yielded 24 serotypes of Salmonella. The predominant serotype were S. seigburg (16 isolates), S. gaminara (6 isolates), and S. thompson (6 isolates). None of the samples yielded S. typhimurium. The frequency of isolation of Salmonella spp. in reptiles (14%) was significantly higher than found in either mammals (7%) or birds (3%). Sixty-five (99%) of 66 Salmonella spp. isolates exhibited resistance to one or more of the nine antimicrobial agents tested. Resistance was high to cephalothin (92%), moderate to streptomycin (35%) and tetracycline (29%), but significantly low to gentamicin (2%), chloramphenicol (0%), and sulphamethoxazole/trimethoprim (0%). The prevalence of asymptomatic infections by Salmonella spp. in zoo animals was high and the very high prevalence of antimicrobial resistance could be a problem when treating salmonellosis.     

Detection of Legionella species in reclaimed water and air with the EnviroAmp Legionella PCR kit and direct fluorescent antibody staining.

Reclaimed water is an important resource for areas with inadequate water supplies. However, there have been few studies on the variety of microorganisms found in this type of water, since typically reclaimed water is examined only for the presence of coliform bacteria. Many microorganisms, including the legionellae, are known to be more resistant to chlorine than are coliform bacteria. Previously, we detected > 10(3) Legionella cells per ml in primary and secondary sewage effluents and observed no significant reduction in population numbers throughout the treatment process. In this study, we detected Legionella spp. in chlorinated effluent by using an EnviroAmp Legionella PCR kit and direct fluorescent antibody (DFA) staining. However, we were not able to isolate Legionella spp. from either natural or seeded reclaimed water samples. This suggests that the Legionella spp. detected by the PCR and DFA methods may be injured or viable but nonculturable after exposure to the high residual chlorine levels typically found in this type of water source. The numbers of coliform bacteria were low (< 2 cells per 100 ml) in most reclaimed water samples and were not correlated with the presence or absence of Legionella spp. We also collected air samples from above a secondary aeration basin and analyzed them by using the PCR, DFA, and plate culture methods. Legionella spp. were detected in the air obtained from above the secondary basin with all three methods. We concluded that the PCR was superior to the culture and DFA methods for detecting Legionella spp. in environmental water samples.     

Taxonomy of bacteria isolated from a coastal, marine fish-rearing unit

Phenetic data on almost 600 aerobic, heterotrophic bacteria from a marine fishrearing unit were collected and analysed using numerical taxonomic techniques. Reference strains, representing 42 taxa were included in the analyses. At similarity levels of 85% or above, with analyses prepared from the simple matching coefficient (S_SM), 81% of the isolates were recovered in eight major and 43 minor phena. Five of the major phena were equated with Acinetobacter calcoaceticus, Photobacterium phosphoreum and Vibrio spp. (three groups); the three unidentified phena contained Gram negative rods with polar flagella which were considered to be intermediate between Cytophaga/Flexibacter and Flavobacterium (two phena), and Gram variable rods. The surface of healthy turbot ( Scophthalmus maximus L. ) was populated by a diverse array of bacteria, including Alcaligenes faecalis, Bacillus firmus, Photobacterium angustum,'Photobacterium logei' and Pseudomonas fluorescens. Taxa, isolated as pure culture growth from within the lesions of moribund animals, included Alteromonas haloplanktis and unidentified Gram negative, budding bacteria. Vibrio anguillarum was not recovered from any turbot suspected of suffering from 'vibriosis'.     

Salmonella spp. in the working environment of sewage treatment plants in Oslo, Norway.

The presence of Salmonella spp. was investigated at three sewage treatment plants in Oslo, Norway. Salmonella bacteria were isolated from floor surfaces and areas with hand contact in the treatment plant, from floor surfaces and areas with hand contact in the treatment plant, from floor surfaces in the changing rooms, and in one case from floor surfaces in an eating room. The sewage sludge contained from 140 to 140,000 Salmonella spp. per 100 g dry weight. Raw and treated sewage contained an average of 130 and 3 of these bacteria per 100 ml, respectively. There was poor correlation between the pattern of serotypes isolated from the sewage works and the patterns of those which were registered among the population of Oslo during the investigation. Neither enteropathogenic bacteria nor parasite eggs were found in fecal samples from employees at the plant. The health significance of the presence of Salmonella spp. in the environment of sewage workers is discussed.