Urban fish as sentinels of public health water significant bacteria

[Peixes urbanos como sentinelas de bactérias aquaticas significativas para a saúde pública]

ABSTRACT

The bacteriological evaluation of the urban fish (Cichlidae) of Lake Pampulha (Belo Horizonte, Brazil) (Cichlidae) was determined at four sites of collection considered with the highest fishing activity. At each site, fish were sampled in triplicate (3 fish), and in total, 24 fish were examined. The samples were found to contain various species of bacteria of family Enterobacteriaceae, Gram-negative non-fermenting (GNNF) bacteria, as well as Aeromonas spp. and Flavobacterium spp. All fish fillets studied were considered of high sanitary risk for consumption. The treatment of fillets with lemon juice, a popular culinary technique employed by the communities, was evaluated for eventual antibacterial property, revealing ineffective. The bacterial taxonomies found, resulting of the high urbanization in the region, including sewage leak or clandestine drainage are of concern. The consumption of the fish of Lake Pampulha may represent a relevant risk to human health in poor communities.

Keywords:
Fecal coliform; total coliform; heat-resistant fecal coliform; Enterobacteriaceae; GNNF; Enterococcus spp; Aeromonas spp; Flavobacterium spp; water quality; Cichlidae; anthropogenic impact; domestic runoff; Pampulha Lake; Belo Horizonte

RESUMO

A avaliação bacteriológica dos peixes urbanos (Cichlidae) da Lagoa da Pampulha (Belo Horizonte, Brasil) (Cichlidae) foi determinada em quatro locais de coleta considerados de maior atividade pesqueira. Em cada local, os peixes foram amostrados em triplicata (3 peixes), e no total foram examinados 24 peixes. Descobriu-se que as amostras continham várias espécies de bactérias dos gêneros Aeromonas spp. e Flavobacterium spp. Todos os filés de peixe estudados foram considerados de alto risco sanitário para consumo. O tratamento dos filés com suco de limão, técnica culinária popular empregada pelas comunidades, foi avaliado quanto a eventual propriedade antibacteriana, revelando-se ineficaz. As taxonomias bacterianas encontradas, decorrentes da alta urbanização da região, incluindo vazamento de esgoto ou drenagem clandestina, são preocupantes. O consumo dos peixes da Lagoa da Pampulha pode representar um risco relevante à saúde humana em comunidades carentes.

Palavras-chave:
coliformes fecais; coliformes totais; coliformes fecais termorresistentes; Enterobacteriaceae; GNNF; Enterococcus spp; Aeromonas spp; Flavobacterium spp; qualidade da água; Cichlidae; impacto antropogênico; esgoto doméstico; Lagoa da Pampulha; Belo Horizonte

INTRODUCTION

Lake Pampulha (Belo Horizonte-Contagem, Brazil) is an artificial body of water constructed in 1938 with the initial objective of creating a reservoir to minimize the effects of heavy regional rain and to be used for recreation. During the subsequent years, it has been transformed into one of the tourist attractions of the city. The lake's drainage basin has an area of 97.91 Km², and geographically defined by the UTM coordinates 78079/77940 N and 5950/6087 E within the metropolitan region, with one part in Belo Horizonte (43.97 Km²), and another part in Contagem (53.94 Km²). The original capacity of the lake, starting from its reconstruction in 1954, was 18.0 x 10⁶ m³, currently reduced to 8.5 x 10⁶ m³, and occupying a surface of 2.08 Km² . The water depth is shallow due to siltation, reaching a depth of 14m close to the spillway. Although Belo Horizonte was planned to stay within the city limit of Avenida do Contorno, there has been an uncontrolled urban expansion towards the periphery around the lake, encroaching on its banks without preservation of its water sources. It drains into the Lake Pampulha, part of the Onça stream basin, one of the tributaries of the Rio das Velhas. The direct tributaries of the lake include the streams Olhos d’Água, Braúna, Água Funda, Tijuco, Mergulhão, Sarandi (Betim) and Ressaca (Contagem), with the last two being the principal ones, contributing 70.00% of the water volume. In 2002 a sewage treatment station for streams Ressaca and Sarandi was inaugurated to reduce the pollution uptake, but did not involve the stream Xangri-Lá, draining sewage of the surrounding homonymous neighborhood, and the portion of stream Sarandi draining sewage of about 3.9 thousand families of Contagem (Centro de Desenvolvimento da Tecnologia Nuclear, 2000; Friese et al., 2010).

The lake is frequently subject to runoff from residential, industrial, and hospital sewage, contributing to an excessive amount of organic material. Consequently, the process of eutrophication has occurred, leading to a reduction of dissolved oxygen (DO) in the water, thereby creating a hostile environment for the flora and fauna, and giving rise to the proliferation of pathogenic microorganisms (Kishinhi et al., 2013) and the accumulation of heavy metals (Rietzler et al., 2001). The microbial content and water quality of the lake has a direct relationship to the health of aquatic organisms.

The disorganized urbanization, deforestation, mining and resultant erosion of headwater stream banks, poor waste disposal, underground sewage discharge into rivers, as well as other factors, have contributed to the gradual deterioration of Lake Pampulha. The excess of the nutrients N₂, P and K (nitrogen, phosphorus and potassium) has resulted in eutrophication that is reflected in the lake's organismal populations, including fish, as well as the sudden rise and proliferation of relatively common algae, bringing both a bad odor and higher fish mortality. In addition, mining in the tributary areas brings about the heavy metal elements as pollutants (Rietzler et al., 2001).

Equally concerning is the presence of pathogenic microorganisms in both the water and fish, due to the elevated levels of organic matter accumulation within the lake. Environments saturated with organic matter (N₂, P and K) are highly favorable for the development of bacteria in the water. Additionally, it has been shown that the normal bacterial flora of fish has a direct relationship with the flora found in the water where they live (Friese et al., 2010).

Fishing is generally practiced by low socio-economic classes, not properly aware of the minimum hygienic requirements during the catch, handling, storage, and consumption. The heat treatment by cooking, however, may not resolve for the presence of heat-resistant toxins (Standard…, 2005). The fish species of Lake Pampulha are members mainly of genus Oreochromis, which were initially introduced to help control of the population of water hyacinth. Oreochromis species can tolerate adverse water quality conditions and other stresses, representing a species of choice, although often succumb to the intense pollution of Lake Pampulha (Centro de Desenvolvimento da Tecnologia Nuclear, 2000; Friese et al., 2010).

The contamination of water basins by sewage discharge represents the main route of transmission of bacteria to fish, mollusks, crustaceans, amphibians and cephalopods, and may directly or indirectly compromise the quality of fish that serve as food for humans and animals. Enteric diseases were related to the consumption of fish-based foods either by improper handling or preexisting contamination from the aquatic environment, conditions which are present in Lake Pampulha, with several reports pointing to the consumption of fish-based food containing heat-resistant toxins (Friese et al., 2010; Muratori, 2000).

Fish contaminated by fecal coliform bacteria or by Escherichia coli may not present any detectable sign of their contamination to the consumer, and their identification can only be carried out by means of microbiological techniques (Muratori, 2000). Other potentially pathogenic bacteria such as Shigella, Aeromonas and Plesiomonas can also play an important role in fish contamination. Aeromonas hydrophila is the species most frequently associated with food-borne diseases and Plesiomonas shigelloides is related to gastroenteritis observed after consumption of fish. Hemorrhagic enteritis was observed inside the digestive tract of Oreochromis caused by Edwardsiella tarda, suggesting that there could be migration of this agent from the intestine to the meat of the fish (Germano et al., 1993; Muratori et al., 2001, 2007; Oliveira and Viegas, 2004). The sharp growth of the low-income population surrounding the region of Lake Pampulha has made fishing become a subsistence activity, a source of food. However, the consumption of fish grown in an unfavorable environment presents risks to consumers of these fish (Brasil, 2001), and to those who enter in contact with the water.

Considering that the bacteriological evaluation of fish meat may be indicative of potentially invasive or toxigenic bacteria, this study aims to determine the aerobic bacterial muscular content in captured fish in Lake Pampulha.

MATERIALS AND METHODS

The four sampling sites for the study of Lake Pampulha (Belo Horizonte, Minas Gerais, Brazil) were chosen considering the occurrence of fishing activity (Figure 1). Thus, every day, fishermen’s can be found in these sites.

Figure 1:
Sampling sites.

Fishes were obtained from local fishermen’s and the number of individuals per sampling was decided in a pilot study. The number of fishes per sampling considered the availability of fishes caught by fishermen and the time that the team took to carry out the microbiological analysis. The study was carried out during one hydrological cycle, i.e., fish were sampled in August and September 2008, and February and March 2009. Over the course of the study, a total of 24 fishes were collected, one triplicate set collected from each site during each sampling. The fish, after being anesthetized and euthanized by cold shock in frozen gel pack container, were placed in plastic bags and sent on ice to the laboratory.

The bacteriological analysis was carried out in the laboratory of Ictiosanidade (Fish Health Laboratory) of the Preventive Veterinary laboratory, Veterinary College, Universidade Federal de Minas Gerais, Brazil.

In the laboratory, fish were dissected in a laminar flow cabinet, for the collection of muscle tissue samples for bacteriology of Enterobacteriaceae, Pseudomonadales, Aeromonas and Gram-negative non-fermenting (GNNF) bacteria (Brasil, 2001; Hofer, 2006; Noga, 1996).

In the laminar flow cabinet, the skin was disinfected using sterile gauze soaked in a solution of 70% ethanol and 0.5% (v/v) iodine. Fillets were removed aseptically through an incision in the posterior dorsal through to the cranial-caudal direction without puncturing the coelomic cavity to avoid contaminating the contents of the digestive tract. Of the material collected, 25g muscle fragments were weighed out using an analytical balance (Sartorius, Germany) inside the laminar flow hood, to maintain the aseptic conditions (Vieira et al., 2004; Hofer, 2006; Agência..., 2001, 2011).

All bacteriological procedures to isolate Salmonella spp., Aeromonas spp., Enterobacteriaceae and GNNF were performed according to previously proposed standards. The protocols followed in this study, “Compendium of Methods for the Microbiological Examination of foods” and the “Bacteriological Analytical Manual” were utilized in accordance with the requirements of Brazilian law pertaining to microbiological exams of foods (Agência..., 2001, 2011; Brasil, 2003).

In the laminar flow cabinet, duplicate fillets were further evaluated to estimate the effect of lemon juice. The fish fillets (muscle tissue) were acidified with lemon juice (pH4.0), as the citric acid of lemon (Citrus aurantifolia) has been described as beneficial for the temporary conservation (Oboh et al., 1995), caused slight decrease in Salmonella Typhimurium as an immediate inhibitor, an effect which increased with time (Kişla, 2007), and such strategy has been used by popular culture in the absence of cold storage.

Enterobacteriaceae, Salmonella and GNNF. Muscle tissues were processed in accordance with the methodology previously described and with the protocols and isolation guidelines proposed by the Brazilian Health Regulatory Agency (Agência..., 2001; Brasil, 2001; Hofer, 2006).

To identify and isolate specific Salmonella spp. and other Enterobacteriaceae, a pre-enrichment technique described by Hofer (2006) was used, which consists of placing the 25 g sample into 100mL of culture medium, with a buffered saline solution of 0.85% NaCl, 1% peptone, homogenizing for 1 minute, and incubating at 37 ºC for 24 hours.

Colonies presenting H₂S production and absence of lactose metabolization (Lac -), suggestive of genus Salmonella, and colonies H₂S negative and Lac positive, suspected of other members of Enterobacteriaceae, were submitted to further biochemical tests and other complementary tests for identification (Hofer, 2006). The isolates classified as GNNF were identified using additional methodology (Schreckenberger, 2000), as described.

For the isolation of Aeromonas spp., muscle samples were inoculated into BHI broth and incubated at 28-30ºC for 24 hours. The BHI growth was plated onto ADE (ampicillin, dextrin, and ethanol) agar plates with strong selection, as is indicated for samples from water polluted by sewage to reduce competing microorganisms. All plates were incubated (28-30ºC / 24 hours) aerobically. ¹⁴ After 18 to 24 hours of growth, the typical yellow colonies, with fermentation of dextrin were selected and plated onto Miller-Hinton (MH) agar for oxidase, catalase, Gram stain tests, and subcultured in OF (oxidation-fermentation) medium, growth in SIM medium (production of H₂S, indole formation, and motility), IAL, LIA (Lisina Iron Agar), TSI (Triple Sugar Iron), and some carbohydrate media (Hugh and Leifson, 1953; Krieg et al., 1984; Imziln et al., 1997; Janda and Abbott, 2010).

RESULTS AND DISCUSSION

The genus/species of fish (PISCES: CICHLIDAE) sampled included Oreochromis spp. (Linnaeus, 1758) Aphia ID: 313195, Cichla ocellaris (Bloch and Schneider, 1801) Aphia ID: 280183 or peacock bass and Geophagus brasiliensis (Quoy and Gaimard, 1824) Aphia ID: 280831, according to the International Code of Zoological Nomenclature (ICZN). The collected fish had a normal appearance indicating apparently healthy. The fish genus/species were all invasive to Lake Pampulha (List, 2024). The genus Oreochromis spp. is originally from Africa and Middle East and became the most cultivated fish genus in aquaculture worldwide, being competitive against native fish fauna to which it may hybridize. Cichla ocellaris is also a locally invasive species, although not negatively impacting the equilibrium of species, original from the Branco River of the Amazon basin in Guiana and Brazil. Geophagus brasiliensis is native to the Argentina, Brazil, Paraguay and Uruguay encounter region in the Parana basin. Figure 2 illustrates the average distribution of different species/genera of bacteria isolated from the fish fillets.

Figure 2
Average distribution of isolates obtained from fillets of cichlids (Cichlidae: Oreochromis spp., Cichla ocellaris and Geophagus brasiliensis) captured from Lake Pampulha in 2008 and 2009.

The highest isolation frequency (37.50%), higher than any of the other isolated bacteria, was obtained for genus Aeromonas spp. (Aeromonadaceae). A large diversity of coliform bacteria (Enterobacteriaceae) was also found in the fillets, mostly identified as E. coli (25%) and Citrobacter spp. (16.67%), in agreement to previous studies (Dufour, 1977; Muratori et al., 2001; Canabarro, 1991; Fatal et al., 1993). The isolation of E. coli and Aeromonas spp. were similar to previous findings in fish grown in tanks with untreated wastewater, with infected muscle tissue, and included Enterococcus spp., even when the MPN was less than 10⁴ CFU/100mL. Other studies with similar results with the isolation of Enterobacteriaceae in muscle were described (Canabarro, 1991; Vieira et al., 2000; Novotny et al., 2004). Aeromonas hydrophila in fresh and ready-to-eat fish with risk for public health may be a major threat (Abd-El-Malek, 2017). However, an environmental benefit by Aeromonas spp. may locally occur, as metal polluted water environments may favor resistant populations of Aeromonas sobria, which absorb and accumulate Cu, Ni and Zn, and could be a promising candidate for heavy metal bioremediation in polluted areas (Qurbani et al., 2022), a condition previously described for Lake Pampulha, being iron and steel industries the probable sources for Fe, Cr, and Ni (Rietzler et al, 2001). Escherichia coli detection in fish meat was considered an indicator of contamination of cooked (23,5%) and uncooked (13.8%) fish in Ethiopia (Yohans et al., 2022). In humans, Aeromonas spp. can cause food infection, gastroenteritis, diarrhea, abdominal pain, ocular infection, infection of the respiratory and urogenital tracts and septicemia (Janda and Abbott, 1996; Imziln et al., 1997; Noga, 1996; Vieira et al., 2004). The muscular infection of fish by Aeromonas spp. may pose a risk for both consumption and handling of the fish (Novotny et al., 2004; Batra et al., 2016). However, the current legislation does not include Aeromonas spp. as indicative of contaminated water or aquatic organisms (Agência…, 2001, 2011; Brasil, 2001). Citrobacter freundii was identified as the cause of a systemic disease characterized by high mortality in rainbow trout (Jeremić et al., 2003) and silver catfish (Bandeira Junior et al., 2018), indicating that its presence in fish muscle may be a result of infection and eventual disease.

The lack of Salmonella isolation may be associated to the large diversity and load of coliform bacteria. Enteric pathogens, such as E. coli and Proteus spp., produce colicins, substances that inhibit the growth of Salmonella, including the species S. Tennessee, S. Newport, S. Enteritidis and S. Schottmuelleri (Paratyphoid B) as well as Shigella spp., results also detected by Frederic and Levine, (1947) and Levine and Tanimoto, (1954). The inability to isolate Salmonella spp. in this study could be related to competition between enteric pathogens (Frederic and Levine, 1947). Levine and Tanimoto, 1954), such as E. coli and Proteus spp., which were found with a high frequency (25% and 8.33%, respectively) in the samples examined. However, in the fish industry, Salmonella spp. may be present in farmed fish feed ingredients and may account for 2% of clinical isolates in Norway (Lunestad et al., 2007).

Escherichia coli is antagonistic and may persist longer than other intestinal bacteria, considered opportunistic pathogens (Hofer, 2006). Considering the current regulations on food microbiological parameters, the presence of coliforms, such as E. coli, Citrobacter spp., Proteus spp. H₂S (-), Enterobacter spp. and Klebsiella spp., is indicative of improper for consumption. (Agência…, 2001 Brasil, 2003; Agência…, 2011). Furthermore, from a sanitation and epidemiological standpoint, this creates a precedent to question the protocols for microbial analysis of food, principally the lack of parameters for the occurrence of other bacterial agents such as Aeromonas spp. The elevated counts of Citrobacter spp., Proteus spp. and E. coli (additionally Enterobacter spp. and Klebsiella spp.) indicate the potential implications to human health (Germano et al., 1993; Vieira et al., 2004).

The bacteria found in the fillets contribute to the deterioration of the fish, in the initial degradation of proteins. After rigor mortis, the number of bacteria increases and, consequently, the enzymes produced accelerate the process of putrefaction by means of decarboxylation and deamination of several amino acids. For example, decarboxylation of lysine and production of cadaverine (by Citrobacter), deamination of tryptophan in putrefaction (by Pseudomonas, E. coli), and the transformation of histidine to histamine (Proteus), which can provoke allergic reactions (Dufour, 1977; Krieg et al., 1984; Hobbs and Roberts, 1999; Schreckenberger, 2000; Hofer, 2006;).

The complete bacteriological analysis of free water bacteria of Lake Pampulha was previously carried out (Fernandes, 2011). In addition to water, the author also analyzed organs, such as the gills and the kidneys, and feces, with occurrences associated with the environmental water. The microbial content of the water is directly related to the health of the aquatic organisms and has a potential public health significance. This study reveals an alarming condition for lower income people eating fish from the lake. The 12.5% occurrence of P. shigelloides in the evaluated fish fillets was similar to the 12.93% findings of Canabarro (1991), investigating fish species sampled at polluted sites in Rio Grande do Sul.

All collected fish were normal and apparently healthy. One direct observation of the study is the apparent lack of association of these bacteria with morbidity of the fish. The bacteriological results may also be relevant exactly due to the lack of an association to a clinical condition. Clearly, these fish can be a source of food poisoning. There is both a direct and indirect risk with consumption, as people in cohabitation may indirectly be challenged (Novotny et al., 2004).

No significant reduction in the bacterial diversity was noted by acidifying with lemon juice (pH4.0), comparing treated and non-treated fish fillets. The citric acid of lemon (Citrus aurantifolia) (2-hydroxypropane-1,2,3-tricarboxylic acid) is the food additive INS 330 and neutralizes amines in the meat, converting into non-volatile forms of ammonia (Kişla, 2007). The treated fillets contained Escherichia coli, Citrobacter spp., GNNF, Alcaligenes faecalis and Aeromonas spp., indicating that acidification was not effective, except for a few taxonomies. Untreated fillets contained, in addition, Enterobacter spp., Klebsiella spp., Proteus spp., P. shigeloides and Pseudomonas spp. However, the utilization of citric extracts was previously employed with satisfactory results, against Gram-negative and Gram-positive bacteria, with lower counts for treated as compared with untreated fillets (Oboh et al., 1995; Adedeji et al., 2007).

The consumption of fish of Lake Pampulha by part of the population, despite the prohibition of fishing, is to be considered a public health issue, especially considering that cooking may not destroy the thermoresistant toxins.

CONCLUSIONS

The fish of Lake Pampulha had a diverse and elevated bacterial occurrence in muscle, in all collection points and in all samplings, reaffirming the sewage pollution, condition which may constitute a public health risk. Considering bacteria, lemon juice was shown not to be efficient for the conservation of fillets prior to cooking. The diverse enteric pathogens found recommends for the need of education and the provision of alternative protein to poorer families by the public agencies. Fish sampling may be a strategy for the prospective evaluation of potentially invasive bacteria of public health significance.

ACKNOWLEDGEMENT

Tico² and Black Bruno for the technical support.

REFERENCES

• ABD-EL-MALEK, A.M. Incidence and virulence characteristics of Aeromonas spp. in fish. Vet. World, v.10, p.34, 2017.
• ADEDEJI, G.B.; FAGADE, O.E.; OYELADE, A.A. Prevalence of pseudomonas aeruginosa in clinical samples and its sensitivity to citrus extract. Afr. J. Biomed. Res., v.10, p.183-187, 2007.
• AGÊNCIA NACIONAL DE VIGILÂNCIA SANITÁRIA. Resolução RDC nº 12, de 2 janeiro de 2001, da Agência Nacional de Vigilância Sanitária - ANVISA. Regulamento técnico sobre padrões microbiológico para alimentos. Diário Oficial da República Federativa do Brasil, 2 janeiro de 2001.
• AGÊNCIA NACIONAL DE VIGILÂNCIA SANITÁRIA. Microbiologia clínica para o controle de infecção relacionada a assistência à saúde. Brasília: ANVISA, 2011. Disponível em: HTTP://www.anvisa.gov.br/faqdinamica/index.asp?Secao=Usuario&usersecoes=28&userassunto=40). Acessado em: 11 fev. 2011.
  » HTTP://www.anvisa.gov.br/faqdinamica/index.asp?Secao=Usuario&usersecoes=28&userassunto=40
• BANDEIRA JUNIOR, G.; SANTOS, A.C.; SOUZA, C.F. et al. Citrobacter freundii infection in silver catfish (Rhamdia quelen): hematological and histological alterations. Microb. Pathog., v.125, p.276-280, 2018.
• BATRA, P.; MATHUR, P.; MISRA, M.C. Aeromonas spp.: an emerging nosocomial pathogen. J. Labor. Physicians, v.8, p.1-4, 2016.
• BRASIL. Ministério da Agricultura Pecuária e Abastecimento (MAPA). Manual de métodos analíticos oficiais para análise microbiológica para controle de produtos de origem animal e água - Instrução Normativa nº 62, de 26 de agosto de 2003.
• CANABARRO, T. Isolamentos de bactérias e vírus em peixes de águas do município de Santa Maria e arredores. Santa Maria, RS. 1991. 81f. Dissertação (Mestrado em Zootecnia) - Curso de Pós-Graduação em Zootecnia, Universidade Federal de Santa Maria, RS.
• Centro de Desenvolvimento da Tecnologia Nuclear (CDTN). Levantamento Eco-Batimétrico da Lagoa da Pampulha: Relatório Técnico. Belo Horizonte, 2000.
• DUFOUR, A.P. "Escherichia coli: the fecal coliform," bacterial indicators/ health hazards asssociated with water. Am. Soc. Testing Mater., Nesp.65, p.48-58, 1977.
• FATAL, B.; DOTAN, A.; PARPARI, L.; TCHORSH, Y.; CABELLI, V.J. Microbiological purification of fish grown in fecally contaminated commercial fishpond. Water Sci. Technol., v.27, p.303-311, 1993.
• FERNANDES, A.A. Estudo bacteriológico da água e de peixes da Lagoa da Pampulha. 2011. 49f. Dissertação (Mestrado em Ciência Animal) - Escola de Veterinária, Universidade Federal de Minas Gerais, MG.
• FREDERIC, P.; LEVINE, M. Antibiotic interrelationships among the enteric group of bacteria. J. Bacteriol., v.54, p.785-792, 1947.
• FRIESE, K.; SCHMIDT, G.; LENA, J.C.; NALINI JR., H.A.; ZACHMANN, D.W. Anthropogenic influence on the degradation of an urban lake-The Pampulha reservoir in Belo Horizonte, Minas Gerais, Brazil. Limnologica, v.40, p.114-125, 2010.
• GERMANO, P.M.L.; OLIVEIRA, J.C.F.; GERMANO, M.I.S. O pescado como causa de toxinfecções bacterianas. Hig. Aliment., v.7, n.28,1993.
• HOBBS, B.C.; ROBERTS, D. Toxinfecções e controle higiênico-sanitário de alimentos. São Paulo: Varela, 1999. 376p.
• HOFER, E. Noções sobre a identificação de bactérias Gram negativas não fermentadoras de importância clínica. Rio de Janeiro: Instituto Oswaldo Cruz Fiocruz, 2006. 10p.
• HUGH, R.; LEIFSON, E. The taxonomic significance of fermentative versus oxidative metabolism of carbohydrates by various Gram negative bacteria. J. Bacteriol., v.66, p.24-26, 1953.
• IMZILN, B.; LAFDAL, O.M.Y.; BARAKATE, M. et al. Pril-ampicillin-dextrin-ethanol agar for the isolation and quantification of Aeromonas spp. from polluted environmental waters. J. Appl. Microbiol., v.82, p.557-566, 1997.
• JANDA, J.M.; ABBOTT, S.L. Human pathogens: the Genus Aeromonas. Clin. Microbiol. Rev., v.7, p.47-55, 1996.
• JANDA, J.M.; ABBOTT, S.L. The Genus Aeromonas: taxonomy, pathogenicity, and infection. Clin. Microbiol. Rev., v.23, p.35-73, 2010.
• JEREMIĆ, S.; JAKIĆ-DIMIĆ, D.; VELJOVIĆ, L.J. Citrobacter freundii as a cause of disease in fish. Acta Vet., v.53, p.399-410, 2003.
• KISHINHI, S.S.; TCHOUNWOU, P.B.; FARAH, I.O. Molecular approach to microbiological examination of water quality in the grand Bay National Estuarine Research Reserve (NERR) in Mississippi, USA. Environ. Health Insights, v.7, p.33-41, 2013.
• KIŞLA, D. Effectiveness of lemon juice in the elimination of Salmonella Typhimurium in stuffed mussels. J. Food Protect., v.70, p.2847-2850, 2007.
• KRIEG, N.E.; HOLT, J.G.; MURRAY, R.G.E.; et al. Bergey's manual of systematic bacteriology. Baltimore: Williams and Wilkins, 1984. 964p.
• LEVINE, M.; TANIMOTO, R.H. Antagonisms among enteric pathogens and coliform bacteria. J. Bacteriol., v.67, p.537-541, 1954.
• LIST of freshwater fishes reported from Brazil. 2024. Available in: https://www.fishbase.de/country/CountryChecklist.php?showAll=yes&what=list&trpp=50&c_code=076&cpresence=Reported&sortby=alpha2&ext_CL=on&vhabitat=fresh Accessed in: 28 Apr. 2024.
  » https://www.fishbase.de/country/CountryChecklist.php?showAll=yes&what=list&trpp=50&c_code=076&cpresence=Reported&sortby=alpha2&ext_CL=on&vhabitat=fresh
• LUNESTAD, B.T.; NESSE, L.; LASSEN, J. et al. Salmonella in fish feed; occurrence and implications for fish and human health in Norway. Aquaculture, v.265, p.1-8, 2007.
• MURATORI, M.C.S. Consórcio suíno-peixe: riscos ambientais e sanitários. Proposta alternativa para descontaminação. 2000. 71f. Tese. (Doutorado em Medicina Veterinária Preventiva) - Escola de Veterinária, Universidade Federalde Minas Gerais, MG.
• MURATORI, M.C.S.; MARTINS, N.E.; PEIXOTO, M.T.D. et al. Mortalidade por "septicemia dos peixes tropicais" em tilápias criadas em consorciação com suínos. Arq. Bras. Med. Vet. Zootec., v.53, p.658-662, 2001.
• MURATORI, M.C.S.; NEVES, R.A.; COSTA, A.P.R. Metodologia alternativa para contagem de bactérias heterotróficas em mãos de manipuladores. Rev. Hig. Aliment., v.21, p.148-149, 2007.
• NOGA, E.J. Fish disease: diagnostic and treatment. St. Louis: Mosby, 1996. 367p.
• NOVOTNY, L.; DVORSKA, L.; LORENCOVA, A.; BERAN, V.; PAVLIK, I. Fish: a potential source of bacterial pathogens for human beings. Vet. Med. Czech, v.49, p.343-358, 2004.
• OBOH, P.A.; AGBONLAHOR, D.E.; EKUNDAYO, A.O.; OWHE-URUGHE, U.B. Antibacterial activity of Citrus arantifolia (Lime) juice against some Gram positive and negative bactéria. Nigerian J. Nat. Appl. Sci., v.2, p.1-9, 1995.
• OGBONDEMINU, F.S.; OKOYE, F.C. Microbiological evaluation of an untreated domestic wastewater aquaculture system. J. Aquacult. Trop., v.7, p.27-34, 1992.
• OLIVEIRA, E.R.; VIEGAS, E.M. Qualidade do pescado. In: RANZANI, P.; TAKEMOTO, R.; LIZAMA, M.A.P. Sanidade de organismos aquáticos. São Paulo: Varela, 2004.
• QURBANI, K.; KHDIR, K.; SIDIQ, A. et al. Aeromonas sobria as a potential candidate for bioremediation of heavy metal from contaminated environments. Sci. Rep., v.12, p.21235, 2022.
• RIETZLER, A.C.; FONSECA, A.L.; LOPES, G.P. Heavy metals in tributaries of Pampulha reservoir, Minas Gerais. Braz. J. Biol., v.61, p.363-370, 2001.
• SCHRECKENBERGER, P.C. Pratical approach to the identification of glucose-nonfermenting Gram-negative bacilli. A guide to identification. 2.ed. Chicago: University of Illinois College of Medicine at Chicago, 2000.
• STANDARD methods for the examination of water and wastewater. 21.ed. Washington, DC: APHA, 2005. 1450p.
• VIEIRA, K.V.M.; MAIA, D.C.C.; JANEBRO, D.I.; VIEIRA, R.H.S.F. Influência das condições higiênico-sanitárias no processo de beneficiamento de tilápia (Oreochromis niloticus) em filés congelados. Hig. Aliment., v.14, p.37-40, 2000.
• VIEIRA, R.H.S.F.; RODRIGUES, D.P.; BARRETO, N.S.E. et al. Microbiologia higiene e qualidade do pescado teoria e prática. São Paulo: Varela, 2004. 380p.
• YOHANS, H.; MITIKU, B.A.; TASSEW, H. Levels of Escherichia coli as bio-indicator of contamination of fish food and antibiotic resistance pattern along the value chain in northwest Ethiopia. Vet. Med., v.13, p.299-311, 2022.

• FUNDING
  Authors are indebted to support by CAPES, FAPEMIG, CNPq and INCT/IGSPB Informação Genética Sanitária da Pecuária Brasileira.

Publication Dates

• Publication in this collection
  28 Apr 2025
• Date of issue
  May-Jun 2025

History

• Received
  13 Dec 2023
• Accepted
  18 June 2024