We report a fatal bacteremia caused by Klebsiella pneumoniae in a 60–70-year-old patient from Brazil. The genomic analysis of three isolates (from blood culture, nasal and anal swabs) showed that the bacteremia was caused by a KPC-2 producing extensively drug-resistant K64-ST11 hypermucousviscous K. pneumoniae (hmKP) harboring several virulence and antimicrobial resistance genes. Although the isolates did not present virulence markers associated with hypervirulent K. pneumoniae (hvKP), they showed invasion and toxicity to epithelial Hep-2 cells; resistance to cell microbicidal mechanisms; and blood and human serum survival, evidencing their pathogenic potential. This study highlights the risk of infection caused by hmKp strains not characterized as hvKP as well as the clinical implications and difficulty of treatment, especially in elderly or immunocompromised patients.

Klebsiella variicola is mainly associated with opportunistic infections and frequently identified as Klebsiella pneumoniae. This misidentification implies a wrong epidemiology result as well as incorrect attribution to K. pneumoniae as the etiology of some severe infections. Recently, huge efforts have been made to study K. variicola, however, the biological aspects of this species are still unclear. Here we characterized five K. variicola strains initially identified as K. pneumoniae, with a Vitek-2 System and 16S rRNA sequencing. One-step multiplex polymerase chain reaction and Whole Genome Sequencing (WGS) identified them as K. variicola. Additionally, WGS analysis showed that all the strains are closely related with K. variicola genomes, forming a clustered group, apart from K. pneumoniae and K. quasipneumoniae. Multilocus sequence typing analysis showed four different sequence types (STs) among the strains and for two of them (Kv97 and Kv104) the same ST was assigned. All strains were multidrug-resistant (MDR) and three showed virulence phenotypes including invasion capacity to epithelial cells, and survival in human blood and serum. These results showed the emergence of new K. variicola clones with pathogenic potential to colonize and cause infection in different tissues. These characteristics associated with MDR strains raise great concern for human health.

The objective of the study is to evaluate a new proposal for a coating based on corn starch (CS) enriched with basil essential oil (BEO) to overcome the rapid deterioration of quail eggs under nonrefrigerated conditions. One hundred and seventy-one quail eggs were divided into treatments of uncoated eggs (control), eggs coated with CS, and eggs coated with CS/BEO, and analyzed over four weeks at room temperature. The CS/BEO coating reduced the growth of total aerobic mesophilic bacteria, Enterobacteriaceae, molds, and yeasts on the surface of eggshells to <2 log₁₀ CFU/mL compared to the control treatment at week four storage. The average Haugh unit (HU) of the four weeks of storage of the CS/BEO treatment was notably higher compared to the control. There was no significant difference between the sensory parameter scores of coated eggs and control treatment. Based on the findings, the CS/BEO coating can be used to mitigate the contamination of quail eggs and preserve their internal quality when stored in an environment without temperature and humidity control.

The aim of this study was to evaluate the effects of a coating formulation involving whey protein isolate (WPI) and garlic essential oil (GEO) on the internal quality and microbiological and sensory attributes of quail eggs stored for 28 days at room temperature. Unwashed quail eggs (171) were divided into treatments of uncoated eggs (UE), WPI-coated eggs and WPI/GEO-coated eggs and analyzed during the study period. Eggs coated with WPI/GEO had 1.51 log₁₀ CFU/mL⁻¹ less aerobic mesophilic bacteria, 2.02 log₁₀ CFU/mL⁻¹ less Enterobacteriaceae and 1.34 log₁₀ CFU/mL⁻¹ less molds and yeasts on the eggshell when compared to UE. The Haugh unit (HU) in the range of 0–28 days of storage was significantly higher for WPI/GEO- (88.26 ± 4.83, grade AA) coated eggs than WPI-coated (86.55 ± 6.20, grade AA) and UE (85.94 ± 6.46, grade AA). The new coating formulation (WPI/GEO) can be an option to preserve the quality of quail eggs.