Prevalence, clonal diversity, and antimicrobial resistance of hypervirulent Klebsiella pneumoniae and Klebsiella variicola clinical isolates in northern Japan.

OBJECTIVES: Hypervirulent Klebsiella pneumoniae (hvKp) and Klebsiella variicola (hvKv) cause hospital/community-acquired infections, often associated with antimicrobial resistance (AMR). This study aimed to investigate the molecular epidemiology of hvKp and hvKv in northern Japan. METHODS: A total of 500 K. pneumoniae and 421 K. variicola clinical isolates collected from August to December 2021 were studied. Prevalence of virulence factor-encoding genes, wzi sequence and associated K/KL type, sequence type (ST), and beta-lactamases and their types were characterized. RESULTS: Any virulence gene (rmpA, rmpA2, peg-344, iucA, iutA, and iroB) and/or magA was detected in 25% (n = 125) of K. pneumoniae and 1% (n = 5) of K. variicola. Among these hvKp/hvKv, 22 wzi types (18 and 4 types, respectively) and 24 STs (20 and 4 STs, respectively) were identified. Sequence types of hvKp were classified into some clonal groups (CGs), among which CG35, including six STs, was the most common (n = 59; 47%), followed by CG23, and CG65. ST268 (CG35) associated with wzi95-K20 or wzi720 was the dominant lineage (n = 43, 34%), while K1:ST23/ST249 and K2:ST65/ST86 accounted for 26% and 13% of hvKp, respectively. Extended-spectrum beta-lactamase (ESBL) genes (blaCTX-M-2, blaCTX-M-3, blaCTX-M-15, and blaCTX-M-27) were detected in only ST23 and CG35 (ST268 and ST412) hvKp. No isolate was resistant to carbapenems, without detection of the ESBL gene in K. variicola. Phylogenetically, wzi was differentiated into two main clusters of K. pneumoniae and K. variicola. A major clonal group CG347 was identified in K. variicola. CONCLUSION: Clonal structures were revealed for hvKp and hvKv clinical isolates with their AMR status in northern Japan.

Streptococcal Toxic Shock Syndrome in a Pediatric Patient With Intramuscular Venous Malformation in the Neck.

BACKGROUND: Streptococcal toxic shock syndrome (STSS) is diagnosed based on signs of shock with multiorgan system involvement, a generalized erythematous macular rash, and rapidly progressive and destructive soft tissue infection. CASE REPORT: The patient was a 2-year-old girl with intramuscular venous malformation in the neck in which an infection occurred, developing into STSS. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Group A streptococcal infections are common in children and usually have a mild clinical presentation, but may be life threatening in severe cases. Patients with venous malformations are known to have slow-flow anomalies with venous pooling, which can result in hypoxia and possible immune cell dysfunction. Thus, clinicians should be aware of STSS when a patient with venous malformation has a rapidly progressive infection.

Clonal diversity of Clostridium perfringens human clinical isolates with various toxin gene profiles based on multilocus sequence typing and alpha-toxin (PLC) typing.

OBJECTIVES: Clostridium perfringens is a common anaerobic pathogen causing enteritis/enterocolitis and wound infections in humans. We analyzed clonal diversity and toxin gene prevalence in C. perfringens clinical isolates from humans in northern Japan. METHODS: Prevalence of nine toxin genes was analyzed for 585 C. perfringens isolates from patients collected for 20-month period between May 2019 and December 2020 by molecular methods. Sequence type (ST) based on multilocus sequence typing (Xiao's scheme) and alpha-toxin (PLC) sequence type were determined for a total of 124 isolates selected in the present study along with those in our previous study (2017-2018). RESULTS: Toxinotypes A (68.2%) was the most frequent, followed by F (31.6%), and G (0.2%), while additional toxin genes encoding binary enterotoxin (BEC/CPILE) and beta2 toxin were identified in one and six isolates, respectively. Among the 124 isolates with various toxin gene profiles, 62 STs including 53 novel types were identified, revealing the presence of six clonal complexes (CCs) consisting of 27 STs. Most of enterotoxin gene (cpe)-positive isolates belonged to CC36, CC41, and CC117. Based on 22 key amino acids in alpha toxin sequence, four PLC types (I-IV) including 21 subtypes were classified, and their relation to individual STs/CCs was clarified. Two isolates harboring bec/cpile belonged to different STs (ST95, ST131) and PLC types (If, IVb), indicating distribution of this toxin gene to distinct lineages. CONCLUSIONS: The present study revealed the diversity in C. perfringens clones of human origin with various toxin gene profiles represented by ST/CC and PLC type.

A Novel Association between the 27-bp Deletion and 538G>A Mutation in the ABCC11 Gene.

A single nucleotide polymorphism in the ABCC11 gene, 538G>A (rs17822931), is known to determine human ear wax type. The G/G and G/A genotypes correspond to the wet type, while the A/A genotype corresponds to the dry type. Another earwax determinant, a 27-bp deletion (Δ27) downstream from the rs17822931 site, is a rare variant that leads to the dry phenotype. In a previous report, we found an individual with the G allele who unexpectedly showed the dry type of earwax, leading to the identification of Δ27. We also demonstrated that the Δ27 allele was present in individuals of Japanese, Thai, native North American, Andean, and Bolivian ancestry but absent in those of European and African ancestry. Here, we assessed the Δ27 allele frequency among Japanese and Ukrainian individuals and identified a novel association between the Δ27 and 538G>A mutations. The Δ27 allele frequency was 0.002 (3/1,520; one individual is heterozygous, and another is homozygous) among Japanese individuals and 0 (0/794) among Ukrainians. We also found a previously unreported homozygous genotype for both the Δ27 and A alleles. Our findings suggest that the Δ27 deletion may have occurred in an ABCC11 gene with the 538G>A mutation.

The availability of perifascial areolar tissue graft for deep cutaneous ulcer coverage.

Soft tissue defects or skin ulcers associated with tendon or bone exposure located distally on the extremities are always difficult to treat. The introduction of the vacuum-assisted closure (VAC) and dermal templates has led to major changes in ulcer treatment strategies. However, it is necessary to find an alternative method to treat these defects when VAC is not available. Perifascial areolar tissue (PAT) is the loose connective tissue on the deep fascia that could be a candidate for repairing soft tissue defects or skin ulcers. Grafting PAT on the exposed bone or tendon, including a wide coverage of well-vascularized tissue surrounding the granulation tissue, can prepare the wound to be subsequently closed by a skin graft. In this study, the PAT was used in various situations and its optimal usage and outcomes were evaluated. A total of 13 PAT grafts were performed and were especially useful for covering narrow ulcers with narrow tendon exposure and filling fistula areas. In comparison to other cases, covering the exposed cortical bone ulcers seemed to be more difficult to perform. However, an option for these ulcers could be the exposure of bone marrow and usage of intraosseous blood flow. It was also possible for the simultaneous engraftment of PAT and skin in narrow areas and could be an alternative in cases of small concave ulcers or fistulae. The PAT graft is a simple and minimally invasive procedure that can be a good alternative when VAC is not available.

Cylinder syringe suction: a simple and efficient technique for the evacuation of subcutaneous hematoma.

BACKGROUND: Subcutaneous hematoma is commonly caused by trauma or surgery. Proper treatment of the condition is needed to avoid severe complications. The present paper introduces a simple technique of hematoma evacuation, called cylinder syringe suction (CSS). Experiments were also performed to determine the detailed mechanism underlying its effectiveness. METHODS: The CSS procedure was performed as follows. A cylindrical plastic cylinder syringe was used. Either a few stitches were removed or a very small incision was made on the site of the hematoma. The edge of the syringe was compressed to the skin, which was covered by a thin hydrocolloid dressing. Vacuum aspiration was enforced at the site of the wound or incision, and the hematoma was gradually aspirated.For the experiment, house rabbits were used. Hematoma evacuation was performed in 4 different ways, including needle aspiration alone (group 1), needle puncture followed by CSS (group 2), and creation of a small wound (5 mm) followed by needle aspiration (group 3) or CSS (group 4). The amount of evacuated hematoma and the suction pressure created by each of the 4 methods were compared. RESULTS: Group 4 showed the highest suction pressure and the greatest evacuated amount of hematoma. High suction pressure was also obtained in group 1; however, the amount of evacuated hematoma was small as the other 2 groups. CONCLUSION: The CSS technique becomes effective mainly by creating high suction pressure, and the opening of a small wound enables the viscous coagula to pass through the skin.

Localization of acyl ghrelin- and des-acyl ghrelin-immunoreactive cells in the rat stomach and their responses to intragastric pH.

Acyl ghrelin has a 28-amino acid sequence with O-n-octanoyl acid modification at the serine 3 position, whereas des-acyl ghrelin has no octanoyl acid modification. Although these peptides exert different physiological functions, no previous studies have shown the different localization of acyl ghrelin and des-acyl ghrelin in the stomach. Here we have developed an antibody specific for des-acyl ghrelin that does not crossreact with acyl ghrelin. Both acyl ghrelin- and des-acyl ghrelin-immunoreactive cells were distributed in the oxyntic and antral mucosa of the rat stomach, with higher density in the antral mucosa than oxyntic mucosa. Immunofluorescence double staining showed that acyl ghrelin- and des-acyl ghrelin-positive reactions overlapped in closed-type round cells, whereas des-acyl ghrelin-positive reaction was found in open-type cells in which acyl ghrelin was negative. Acyl ghrelin-/des-acyl ghrelin-positive closed-type cells contain obestatin; on the other hand, des-acyl ghrelin-positive open-type cells contain somatostatin. We measured the release of acyl ghrelin and des-acyl ghrelin in vascularly perfused rat stomach by ELISA, and the effects of different intragastric pH levels on the release of each peptide were examined. The release of des-acyl ghrelin from the perfused stomach was greater at pH 2 than at pH 4; however, the release of acyl ghrelin was not affected by intragastric pH. The present study demonstrated the differential localization of acyl ghrelin and des-acyl ghrelin in the rat stomach and their different responses to the intragastric pH.