Co-transmission of Rahnella aquatilis between hospitalized patients

Microbial Safety of Smoothie Drinks from Fresh Bars Collected in Slovakia

Among the many consumers in Slovakia, smoothies are nowadays gaining popularity. Smoothie drinks are prepared from raw fruits and vegetables. Therefore, their microbiological safety depends on hygiene standards. The aim of this work was to monitor and quantify selected sensitive and antibiotic-resistant microorganisms present in collected smoothies. Twenty analyzed smoothie samples were collected from six food service establishments (fresh bars) in the capital city of Slovakia, Bratislava. Antibiotic-resistant bacteria were found in at least one of each fresh bar. Antibiotic-resistant coliform bacteria prevailed, especially in green smoothies or juices containing more vegetable ingredients. Resistance to ampicillin, ciprofloxacin, tetracycline, chloramphenicol, and gentamicin was observed in the case of coliform bacteria. More than half of the smoothie drink samples did not contain resistant enterococci. On the other hand, vancomycin-resistant enterococci were detected in 20% of samples. The most frequently isolated antibiotic-resistant strains belonged to the Enterobacter spp. or Klebsiella spp. genus. In the last part of the work, the pretreatment effect of smoothie components on the selected microorganisms' counts in the final product was investigated. Washing ingredients with an aqueous solution of a biocide agent containing silver and hydrogen peroxide proved to be the most effective way to decrease bacterial counts.

Game animals as a reservoir of rarely recorded opportunistic bacteria

In Poland, the population of game animals, including wild boars, roe and deer, is constantly increasing. The tonsils of wild game animals are a place of large variety of microorganisms. The pathogenic bacteria present in them, such as E. coli, Y. enterocolitica and Salmonella sp. are the most common source of meat infection. The opportunistic bacteria R. aquatilis, P. fluorescens, S. liquefaciens, S. fonticola and S. plymuthica also play an important role in public health. S. liquefaciens may be an opportunistic pathogen and in people causes sepsis and inflammation of the cornea. The protease, nuclease, phospholipase A, flagella, elastase and toxins haemolysin and proteolysin are responsible for its ability to cause disease symptoms. S. plymuthica, a rod commonly found in the environment, produces a red dye. It is most often isolated from soil, water and food. In humans, it causes infections of burn wounds, soft leg tissue as well as post-operative wounds and bacteraemia. Typically, the environmental rod S. fonticola differs from other Serratia sp. by the lack of extracellular enzymes. It causes wound infections and bacteraemia resulting from urinary tract infections. Bacteria from the genus Serratia sp. show a natural resistance to glycopeptides, rifampicin and erythromycin. The aquatic rod R. aquatilis in humans causes opportunistic infections of the urinary tract, wounds, bacteraemia and endocarditis. It exhibits natural resistance to antibiotics from the group of cephalosporins, penicillins and macrolides and quinolones. It is conditioned by the presence of class 1 integrons and class A β-lactamases. The virulence factors of R. aquatilis are also LPS and adhesin. P. fluorescens in humans is responsible for bacteraemia. It also exhibits resistance to human serum thanks to outer membrane proteins and has T3SS, which effectively infects the host.

Use of MALDI-TOF MS to identify the culturable midgut microbiota of laboratory and wild mosquitoes

Mosquitoes are responsible for transmitting many pathogens to humans and Aedes aegypti, Aedes albopictus and Culex quinquefasciatus are important vectors in the world. The microbiota plays an important role in developmental studies that involve impacts on the biological cycle of mosquitoes and vector control strategies. In this study, the aim was to understand the environment plays in the microbiota culturable diversity of Aedes aegytpi, Aedes albopictus and Culex quinquefasciatus. Midgut of studied mosquitoes (laboratory-reared and wild) were dissected and analyzed by MALDI-TOF MS to identify the microbiota. Most of the bacteria identified in the microbiota of mosquitoes from the laboratory and field belong to the phylum Proteobacteria. We reported on the microbial diversity among the mosquito species studied where Cx. quinquefasciatus and Ae. albopictus show greater bacterial similarity. The genus Rahnella was present in all mosquito species studied, both in those from the laboratory and those from the wild. Bacillus, Ewingella, Microccocus, Klebsiella and Pantoea are genera was predominant among the mosquitoes studied. The difference of microbiota diversity between mosquitoes laboratory-reared and wild shows that the environment plays an important role in the acquisition of bacteria, mainly in Ae. aegypti and Cx. quinquefasciatus.

Hexadecane biodegradation of high efficiency by bacterial isolates from Santos Basin sediments

The aim of the study was the investigation of bacterial diversity from sediments collected at Santos Estuarine System, regarding to their abilities for hexadecane biotransformation. Hexadecane is a medium-chain linear alkane, considered as a model molecule for hydrocarbon biodegradation studies. It is a component from aliphatic fraction of crude petroleum, commonly related to environmental contamination by diesel oil. Santos Basin is an area with historical petroleum contamination. In the present work, sediment samples from this area were inoculated in artificial seawater (ASW), containing hexadecane as carbon source. Six bacterial isolates were selected as resistant to hexadecane. Chromatographic results showed biodegradation indexes above 97%. After 48 h of culture, five of them could degrade >80% of the initial hexadecane added. These isolates were characterized by 16S rDNA gene sequencing analysis. The following species were found: Bacillus amyloliquefaciens, Staphylococcus epidermidis, Micrococcus luteus, Nitratireductor aquimarinus, and Bacillus pumilus.