Evaluation of selective media for isolation and enumeration of vibrios from estuarine waters

We have compared the effectiveness of four media developed in the last years together with the medium GSTC(glucose-salt-tellurite-crystal violet), devised in our laboratory, for the recovery of vibrios from estuarine waters. In addition, a number of reference Vibrio and non-Vibrio strains have been tested for growth on the five media. TCBS and GSTC were the most selective media for reference strains of Vibrio spp. However, when the media were tested with samples of water from three different sites of an estuary, only TCBS was effective enough to recover vibrios inhibiting the growth of non-Vibrio populations. We also report here the usefulness of TCBS for isolation of the fish pathogen V. anguillarum, since a total of 81 strains isolated from diseased fish and water in various parts of the world grew on this medium. In conclusion, we consider the TCBS as the best medium to isolate Vibrio species pathogenic for humans and fish, and for recovery of vibrios from estuarine waters.     

A note on the enumeration of manganese-oxidizing bacteria in estuarine water and sediment samples

V ojak , P.W.L., E dwards , C. & J ones , M.V. 1985. A note on the enumeration of manganese-oxidizing bacteria in estuarine water and sediment samples. Journal at Applied Bacteriology 59, 375–379.
Media for the enumeration of manganese-oxidizing bacteria in estuarine water and sediment samples were compared. A peptone/yeast extract medium containing manganese sulphate and 30% (v/v) sea salts solution gave the highest percentage of manganese-oxidizers and high total viable counts. A survey of estuarine (River Tamar) and marine (English Channel) sites indicated that manganese-oxidizing bacteria comprise a significant but variable proportion (11–85%) of the total bacterial count.     

A method of the selective isolation and enumeration of marine Vibrionaceae

A noninhibitory medium and GasPack anaerobic culture system were employed for the selective enumeration and isolation of Vibrionaceae in seawater and marine sediments.Vibrio counts obtained by the new method for seawater and sediment samples were compared with vibrio numbers in the heterotrophic bacterial population appearing on a medium routinely employed in the laboratory for such counts. The ratio of the former to the latter counts ranged from 0.5 to 1.3, the average being 0.96. The seawater and sediment bacteria that grew and produced visible colonies on the medium under anaerobic conditions for 3 days at 20°C were almost exclusively vibrios.From the results reported here it is concluded that most of the vibrios present in seawater and sediment samples can be recovered by the new method developed in this study.     

Indicator organisms for estuarine and marine waters

Abstract The use of indicator organisms for estuarine and coastal waters has been reviewed. The natural flora of the environment must be considered in selecting an indicator organism, but, more importantly, recent work which shows a viable but non-recoverable stage of pathogens entering the marine environment demonstrates that the conventional detection of indicator microorganisms is misleading, if not inaccurate. Results suggest that the newly developed epifluorescent/immunofluorescent direct detection of pathogens in the environment may be the most reliable method for determining public health hazards in marine and estuarine waters.     

A note on the isolation and enumeration of bacteria which deposit and reduce ferric iron

Media and methods suitable for the isolation of iron-depositing and iron-reducing bacteria from aquatic habitats are described. Higher MPN estimates were obtained, and a greater variety of bacteria isolated, when the media were made up in a semi-solid form with a final agar concentration of 0.25%.     

Stability of human enteroviruses in estuarine and marine waters.

Studies of the effects of temperature and salinity on the survival of three enteric viruses (poliomyelitis type 1, echovirus-6, and coxsackievirus B-5) under controlled laboratory conditions and in situ indicate that temperature rather than salinity is the critical factor affecting their stability, in that the higher the temperature the more rapid was the loss of viral infectivity. In the laboratory studies, all three viruses were quite stable at 4 degrees C, with infectious virus still detectable after 46 weeks of incubation. In situ studies on virus survival in free-flowing estuarine or marine waters showed that, although the viruses were more labile in natural waters than in the laboratory studies, they persisted for several months, in some cases during the winter months. At all temperatures and salinities, coxsackievirus B-5 was the most stable, echovirus-6 was intermediate, and poliovirus 1 was the least stable of the viruses tested.     

Stability of human enteroviruses in estuarine and marine waters.

Studies of the effects of temperature and salinity on the survival of three enteric viruses (poliomyelitis type 1, echovirus-6, and coxsackievirus B-5) under controlled laboratory conditions and in situ indicate that temperature rather than salinity is the critical factor affecting their stability, in that the higher the temperature the more rapid was the loss of viral infectivity. In the laboratory studies, all three viruses were quite stable at 4 degrees C, with infectious virus still detectable after 46 weeks of incubation. In situ studies on virus survival in free-flowing estuarine or marine waters showed that, although the viruses were more labile in natural waters than in the laboratory studies, they persisted for several months, in some cases during the winter months. At all temperatures and salinities, coxsackievirus B-5 was the most stable, echovirus-6 was intermediate, and poliovirus 1 was the least stable of the viruses tested.     

Life cycles and distribution of atherinids in the marine and estuarine waters of southern Australia

New and published data have been collated for the biology and distribution of atherinid species abundant in the coastal saline waters of Australia below 30°S. This information has been used to determine whether these species typically spawn at sea or pass through the whole of their life cycle in estuaries, and in one case, also lagoons and saline lakes. Length-frequency data, gonadosomatic indices and distribution records indicate that in south-eastern AustraliaCraterocephalus honoriae andAtherinosoma microstoma typically reach total lengths less than 90 mm, have a one-year life cycle and breed within estuaries. This parallels the situation recently described forAtherinosoma elongata, Atherinosoma wallacei andAllanetta mugiloides in south-western Australia (Princeet al., 1982a; Prince & Potter, 1983). The marine speciesAtherinosoma presbyteroides, which reaches a similar size and has a one year life cycle in both south-western and south-eastern mainland Australia, only enters estuaries in large numbers in the former region. WhileAtherinomorus ogilbyi is also found in estuaries and typically breeds at sea, it reaches total lengths as great as 189 mm and has a longer life thanA. presbyteroides. The limited data forAtherinason esox andAtherinason hepsetoides demonstrate that both these marine atherinids can attain total lengths of 139 and 108 mm respectively and live for longer than a year but do not enter estuaries in large numbers. The latter species is unique amongst southern Australian atherinids in having a distribution which extends into deeper water. It is suggested that landlocking may have played a role in the evolution and success of the estuarine mode of lifesensu stricto ofA. wallacei, A. elongata, A. microstoma, A. honoriae andA. mugiloides in southern Australian waters.     

A note on a membrane filtration method for the concentration and enumeration of bacteriophages from water

A membrane filtration method is described for the recovery and enumeration of bacteriophage from water. The method is conveniently used in the field and requires no complex or expensive equipment.     

Comparative study of enrichment methods for the isolation of autotrophic nitrifying bacteria from soil, estuarine and marine sediments

Abstract A comparative study has been undertaken to determine the efficiency of methods for the enrichment and isolation of autotrophic nitrifying bacteria from soils and estuarine and marine sediments. Chemostat enrichments proved to be the most efficient means of isolating autotrophic NH⁺₄ oxidisers whereas NO⁻₂ oxidising bacteria were never successfully enriched by this method. In contrast, gel enrichment and traditional batch culture enrichments of nitrifying bacteria were comparatively time consuming procedures and the degree of enrichment obtained for NH⁺₄ oxidising bacteria never approached that obtained with continuous culture enrichments. Gel enrichments, however, because they have continuous physicochemical gradients provide qualitative advantages in that morphologically distinct types of nitrifying bacteria can be isolated from the same gel.     

A note on the isolation of psychrotrophic coliform organisms from faecal-polluted environments

The Simmons citrate salicin (SCS) medium was developed for the enrichment and isolation of presumptive psychrotrophic coliforms from polluted environments. The selectivity and resolution of the medium were tested with pure and mixed laboratory cultures. A procedure for the isolation of psychrotrophic coliforms from polluted environments using a lactose-bile broth and SCS medium is presented.     

A note on the isolation of psychrotrophic coliform organisms from faecal-polluted environments

The Simmons citrate salicin (SCS) medium was developed for the enrichment and isolation of presumptive psychrotrophic coliforms from polluted environments. The selectivity and resolution of the medium were tested with pure and mixed laboratory cultures. A procedure for the isolation of psychrotrophic coliforms from polluted environments using a lactose-bile broth and SCS medium is presented.     

A note on the isolation of Staphylococcus aureus from raw minced meat

Conventional Baird-Parker medium (BP) and three modified BP-type media were tested for their suitability to detect and to enumerate Staphylococcus aureus in raw minced meat. BP with pig plasma gave the most rapid results without the need for extensive confirmatory tests. A method which combined a liquid modification of BP medium with BP agar supplemented with acriflavine, polymyxin and sulphamezathine, was cheaper, more sensitive, and did not necessitate additional identification. Conventional BP incubated at 37 degrees and 43 degrees C yielded less satisfactory results.     

A note on the isolation of pathogenic aerobic actinomycetes from sudanese soils

A preliminary investigation of two methods of isolating pathogenic aerobic actinomycetes from a group of Sudanese soils was undertaken. By one method,Nocardia asteroides was isolated from 3 out of 4 soils. By the second method, two strains ofN. brasiliensis and three ofActinomadura madurae were recovered from 4 out of 10 soils. Both procedures seem to be advantageous for isolating pathogenic aerobic actinomycetes from soils.     

A note on the isolation of Staphylococcus aureus from raw minced meat

Conventional Baird-Parker medium (BP) and three modified BP-type media were tested for their suitability to detect and to enumerate Staphylococcus aureus in raw minced meat. BP with pig plasma gave the most rapid results without the need for extensive confirmatory tests. A method which combined a liquid modification of BP medium with BP agar supplemented with acriflavine, polymyxin and sulphamezathine, was cheaper, more sensitive, and did not necessitate additional identification. Conventional BP incubated at 37 and 43C yielded less satisfactory results.