Category Archives: Aeromonas

Research – Bacterial biofilm reduction by 275 and 455 nm light pulses emitted from light emitting diodes

Wiley Online

Biofilm of antibiotic resistant bacteria. Rod-shaped and spherical bacteria. Escherichia coli, Pseudomonas, Mycobacterium tuberculosis, Klebsiella, Staphylococcus aureus, MRSA. 3D illustration


Eradication of biofilms from the food contact surfaces is a challenging task, owing to their increased resistance to sanitizers and regular cleaning practices. The treatment with the light pulses emitted from the light emitting diode (LED) is an emerging surface decontamination technology, that can produce the antibiofilm effect by photodynamic inactivation. The objective of this study was to understand the antibiofilm efficacy of the 275 (Ultraviolet-C [UV-C]) and 455 nm (Blue) light pulses emitted from the LEDs against single and dual-species biofilms of Salmonella Typhimurium ATCC13311 and Aeromonas australiensis 03-09 on stainless steel (SS) coupons formed at different time. The biofilm formation by S. Typhimurium was improved when grown with A. australiensis in dual-species culture. Both 275 and 455 nm light pulses showed significant antibiofilm activity against S. Typhimurium and A. australiensis in single and dual-species biofilms. For instance, the 275 nm LED treatment of surfaces of SS coupons with 1.8 J/cm2 dose on each surface, produced reductions of 4.24 and 3.9 log (CFU/cm2) in single (cell attachment) and dual-species biofilms of S. Typhimurium, and reductions of 4.45 and 4.99 log (CFU/cm2) in single and dual-species biofilms of A. australiensis. However, the susceptibility of A. australiensis toward 455 nm LED treatments was influenced by the presence of S. Typhimurium in the dual-species biofilm. The confocal laser scanning microscopy images revealed significant cell membrane damage in the dual-species biofilms by the LED treatments with 275 and 455 nm light pulses. Overall, several factors like surface temperature increase, strains used, treatment dose, treatment time, and incubation period of biofilms influenced the inactivation efficacy of the 275 and 455 nm LED treatments against the biofilms formed on SS coupons. This study provides an insight into the inactivation efficacy of LED light pulses against bacterial biofilms on food grade SS surfaces.

Research -Application of a novel phage ZPAH7 for controlling multidrug-resistant Aeromonas hydrophila on lettuce and reducing biofilms

Science Direct


Aeromonas hydrophila is an important pathogenic bacterium that causes foodborne illness worldwide. In this study, virulent phages from the sediment of a fish farm were propagated and isolated on a multidrug-resistant strain of A. hydrophila, ZYAH75. One phage, designated as ZPAH7, featured a unique turbid halo around a clear plaque on the bacterial lawn (indicative of potential depolymerase activity), and was selected for further analysis. ZPAH7 was classified as podophage by morphological and genomic methods. Further comparisons of genome nucleotide similarity, ratios of homologous proteins and phylogenetic relatedness among the terminase large subunit and major capsid proteins of similar phage deposited in GENBANK, led us to propose a new genus, ZPAH7virus, in the Autographivirinae subfamily of Podoviridae. ZPAH7 had an adsorption rate of 79% in 5 min, an eclipse period of 15 min, a latent period of 25 min, and a burst size of 148 ± 9 PFU/cell. Antimicrobial application experiments showed that ZPAH7 lead to significantly reduction on A. hydrophila on lettuce. Additionally, ZPAH7 was able to inhibit biofilm formation, as well as degrade and kill bacteria in established biofilms. Furthermore, lytic activity of ZPAH7 remained stable across a wide range of temperatures and pH measurements. These results suggest ZPAH7 could be used as a potential biological control agent against A. hydrophila on food and/or biofilms on food contact surfaces.

Research – Characterization of Microbiological Quality of Whole and Gutted Baltic Herring


There is growing interest in Baltic herring (Clupea harengus membras) and other undervalued, small-sized fish species for human consumption. Gutting or filleting of small-sized fish is impractical; hence, the aim of this study was to explore the suitability of the whole (ungutted) herring for food use. The microbiological quality of commercially fished whole and gutted herring was analysed with culture-dependent methods combined with identification of bacterial isolates with MALDI-TOF Mass Spectrometry and culture-independent 16S rRNA gene amplicon sequencing. Whole and gutted herring had between 2.8 and 5.3 log10 CFU g−1 aerobic mesophilic and psychrotrophic bacteria and between 2.2 and 5.6 log10 CFU g−1 H₂S-producing bacteria. Enterobacteria counts remained low in all the analysed herring batches. The herring microbiota largely comprised the phyla Proteobacteria, Firmicutes, and Actinobacteria (71.7% to 95.0%). ShewanellaPseudomonas, and Aeromonas were the most frequently isolated genera among the viable population; however, with the culture-independent approach, Shewanella followed by Psychrobacter were the most abundant genera. In some samples, a high relative abundance of the phylum Epsilonbacteraeota, represented by the genus Arcobacter, was detected. This study reports the bacterial diversity present in Baltic herring and shows that the microbiological quality was acceptable in all the analysed fish batches. View Full-Text

Slovakia – Report on zoonoses, foodborne diseases and waterborne diseases in the Slovak Republic in 2020



The protection of human and animal health can only be achieved through the active cooperation of experts in the field of control and research in the human and veterinary field. The report on zoonoses, foodborne diseases and waterborne diseases in the Slovak Republic for 2020 contains data from official inspections carried out in the field of agriculture and health care, as well as from research institutes and universities. The preparation of the report was coordinated by the National Contact Point for Scientific and Technical Cooperation with the European Food Safety Authority (EFSA EFSA), which is established at the Department of Food Safety and Nutrition of the Ministry of Agriculture and Rural Development of the Slovak Republic (MPRV SR).

The report serves as a basis for the EFSA NCB and scientific experts to set priorities and own national food safety risk assessments. At the same time, the report serves as one of the bases for the Community risk assessment carried out by the European Food Safety Authority (EFSA). Scientific risk assessment is the basis for risk management. The report describes the situation in  35 zoonotic agents, 5 foodborne diseases (ie foodborne diseases) without zoonotic potential and 4 waterborne pathogens. Of the 44 agents monitored, 23 are bacterial, 10 parasitic, 10 viral and prion.

It presents the summary results of examinations and tests performed in 2020 in the Slovak Republic and the evaluation of the national epidemiological situation in humans and animals with a focus on trends and sources of zoonotic and foodborne diseases.

The report presents the summary results of examinations and tests carried out in 2020 and an assessment of the national epidemiological situation in humans and animals , focusing on trends and sources of zoonotic and foodborne diseases . The number of monitored authors, cooperating organizations and experts is growing every year. A wide team of more than 70 experts from 24 scientific and control organizations in the Slovak Republic took part in its elaboration .

In 2020, 17,067 human diseases caused by the study agents were reported, with 29.1% related to campylobacteriosis, 20.9% to Clostridium dificille and 20.4% to salmonellosis. Rotavirus 11.6%, Norwalk virus 5.1%, Borrelia burgdorferi sl 5.6% and  Escherichia coli 1.2% also contributed to a higher percentage of diseases.

Seven of the study agents caused 380 human epidemics, of which 56.6% were salmonellosis, 23.2% were campylobacteriosis and 12.6% of epidemics were caused by rotavirus. Norwalk virus accounted for 5.5%, tick-borne encephalitis virus 1.3%, shigella and 0.5% and yersinia 0.3%.  

35,957 food samples were examined for the presence of 15 pathogens with a positive finding in 2.2% of samples. Higher percentages of positive findings were in  Yersinia spp. 48.1%, Enterococcus spp. 46.3% and  Vibrio spp. 31.8%.

The presence of 30 pathogens was monitored in 2,483,239 samples originating from livestock and wild animals, pets and zoos taken as part of official control, preventive monitoring, research, as well as from sick or dead animals. Positive findings accounted for 0.1% of samples. Higher percentages of positive findings were recorded for  Aeromonas spp. 59.3%, Clostridium spp. 55.4%, Francisella tularensis 50.4%, Babesia spp. 41.1%, Dirofilaria spp. 34.8%, Campylobacter spp. 18.3%, Yersinia spp. 18.3%, Staphylococcus aureus 18.1%, hepatitis E virus 14.1%, Listeria monocytogenes  11.8%, Toxocara spp. 10.5%.

Feed – 385 samples were examined for the presence of Salmonella spp. (1.5% positive samples), Escherichia coli (60.0% positive samples) and Clostridium spp.

(1.7% positive samples).

35,746 water samples were examined for the presence of 9 agents, of which 7.4% were positive, of which Legionella spp. 47.1% and Vibrio spp. 39.5%.

44,633 samples from the environment were examined for the presence of 8 pathogens, of which 2.3% were positive, of which Legionella spp. 36.0%, Vibrio spp. 6.8%,  E.coli 3.6% and  Enterococcus spp. 2.6%.

The report also includes the results of examinations for the resistance of microorganisms to antimicrobials, which has a growing trend worldwide and poses a real danger in the treatment of infections. Microbial resistance was monitored in Salmonella spp., E. coli , Campylobacter spp., Staphylococcus aureus and  Enterococcus spp.

The comprehensive report, which will be published as a publication, has a length of more than 130 pages, will be published in printed form, as a publication with an assigned ISBN. Summaries of individual chapters will be translated into English and published in an electronic version as a publication with an assigned ISBN.

See the appendices for more information.

Attachments (downloadable documents)


RASFF Alert – Aeromonas spp – Chilled Milk


RASFF -Aeromonas hydrophila and Aeromonas caviae in chilled milk from Germany in Germany