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Background: Biomechanical analysis using cyclic testing for repaired flexor tendons is a clinically relevant method. The aim of this study was to evaluate the tensile properties of two six-strand suture techniques, the triple looped suture and Yoshizu #1 suture techniques using cyclic testing under simulating early active mobilization conditions., Methods: Twenty-five flexor digitorum profundus tendons harvested from fresh frozen human cadaver hands were repaired in zone 2 utilizing one of three repair techniques: the 2-strand modified Kessler (MK) technique as a control, the triple looped suture (TLS) and Yoshizu #1 suture (Y1) techniques. In each suture technique, 4-0 monofilament nylon sutures were used for core sutures and 6-0 monofilament nylon sutures for circumferential running sutures. Cyclic testing was performed using 20 N with 600 cycles at 1 Hz., Results: Five out of eight specimens in the MK group ruptured during cyclic testing. Thus, this group was excluded from analysis. On the other hand, all tendons in the TLS and Y1 groups tolerated cyclic testing. Average gaps of the TLS and Y1 groups were 0.5 ± 0.8 mm and 1.9 ± 2.2 mm, respectively. All tendons in the TLS group and six out of nine tendons in the Y1 group formed gaps less than 2 mm. Two tendons in the Y1 group formed a gap of 3.8 and 6.6 mm had breakage of peripheral sutures at the first cycle. Mean ultimate tensile force of the TLS and Y1 group measured after cyclic tensing, were 66.2 ± 9.0 N and 65.9 ± 13.1 N, respectively. No statistical difference between the two groups was found in gap and ultimate tensile forces., Conclusions: This study suggested that the TLS and Y1 techniques have tensile properties to allow early active mobilization. None of tendons repaired with the TLS technique had gaps more than 2 mm., Competing Interests: Declaration of competing interest None of authors declare conflicts of interest., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Pneumonia is a common disease among the aging population in Japan. Hence, it is important to elucidate the risks related to pneumonia mortality. Since Streptococcus pneumoniae is the most commonly observed pathogen, pneumococcal vaccination is recommended to older adults. Therefore, this study aimed to clarify the clinical features of pneumonia, including the status of pneumococcal vaccination, in hospitalized older adult patients in Japan., Methods: This single-centered retrospective study was conducted by reviewing the medical records of all patients with acute pneumonia at Fujisawa City Hospital in Japan from April 2018 to March 2019. Patients were divided into two groups based on their history of pneumococcal vaccination. The primary endpoint was in-hospital mortality, while the secondary endpoint was risk factors associated with mortality., Results: We included 93 patients with pneumonia in this retrospective study. Although the mortality rate was higher in the vaccinated group (15.8%) than in the unvaccinated group (9.1%), vaccination status was not identified as a significant risk factor for mortality after multivariable logistic regression (odds ratio: 2.71; 95% confidence interval: 0.667-11.02; p =0.16). In addition, the A-DROP score was identified as an independent risk factor (odds ratio: 2.64; 95% confidence interval: 1.22-5.72; p =0.008)., Conclusions: Our study suggested that the A-DROP score is a risk factor of mortality for pneumonia in older adults. In addition, pneumococcal vaccination history was related to increased mortality; however, the influence of the vaccination remains unclear because of the small sample size., Competing Interests: The authors declare no conflicts of interest regarding the publication of this paper., (Copyright © 2021 Nobuhiko Fukuda et al.)

In Japan, clinical and experimental studies addressing COVID-19 have been increasing in number since early February 2020, with many case reports being published. Concurrently, many notifications and guidelines have been issued from the government and academic societies. Taking optimal measures at the prefectural level as well as the national level is necessary to prevent the spread of COVID-19. Surveying and analyzing details of the incidences of infected persons in each prefecture is extremely important. This report describes the epidemiological characteristics of COVID-19 observed in Okayama Prefecture, followed by discussion of the direction of public health actions to be taken in the future. We reiterate the crucial importance of reinforcing and maintaining current public health measures, including rapid and detailed compilation of information related to infected persons and their surroundings, appropriate blocking of viral transmission, and early containment of infected persons, to minimize the spread of infection especially during the overlapping epidemic period of influenza in Okayama Prefecture., Competing Interests: The authors have no conflicts of interest to disclose., (2021, National Center for Global Health and Medicine.)

Purpose: To compare 2 types of newly devised 8-strand quadruple-looped suture (QLS) techniques with a 6-strand triple-looped suture (TLS) technique; and to assess the effects of different core suture lengths (CSLs) (the length between 2 locking sites of a suture strand) within each suture row on tensile strength., Methods: We repaired 24 flexor tendons from 12 rabbits using the TLS and QLS techniques, with equal CSL (QLS) or unequal CSL (unequal QLS) among each suture row. The QLS was composed of 4 looped sutures on the anterolateral and posterolateral aspects of the tendon. The cross-sectional area of the locking portion of each thread in the QLS was equal to that in the TLS. In the QLS technique, the CSL on each aspect of the tendon was 13 mm. In the unequal QLS technique, the CSL on each aspect of the tendon was 13 and 17 mm. The load at 1- and 2-mm gaps, the maximum load until the 3-mm gap, and the ultimate load were compared among the 3 techniques., Results: The QLS was significantly stronger than the unequal QLS and the TLS for loads at 1-mm and 2-mm gaps, maximum load until 3-mm gap, and ultimate load. There was no significant difference between the unequal QLS and TLS techniques. The QLS technique showed an approximately 30% increase in gap resistance and ultimate strength compared with the TLS technique., Conclusions: The QLS technique showed an estimated increase in tensile strength proportional to the number of suture strands compared with the TLS technique. Our study suggests that a consistent CSL in each suture row provides the highest strength in multistrand sutures consisting of the same configuration of suture rows., Clinical Relevance: The QLS technique may reduce the risk for tendon rupture associated with early active mobilization after flexor tendon repair., (© 2020 The Authors.)

A 57-year-old man was diagnosed with IgA nephropathy. Hematuria and proteinuria were improved by tonsillectomy plus methylprednisolone pulse therapy. Lymphadenopathy, hypocomplementemia and pancytopenia were observed six years later, and urinalysis abnormalities recurred. A biopsy revealed mesangial proliferative glomerulonephritis with C3-dominant deposition. Human immunodeficiency virus (HIV) antibody demonstrated positive conversion. He was diagnosed with HIV-associated immune complex kidney disease (HIVICK). The hematuria, proteinuria and hypocomplementemia were improved by reducing the HIV viral load through antiretroviral therapy. When C3-dominant deposition is observed on a renal biopsy, HIVICK must be differentiated.

Background: The increase in the use of cardiac implantable electronic devices (CIEDs) has been associated with an increase in CIED-related infections. Transvenous lead extraction is safe and effective for patients with CIED-related infections; however, the mortality rate in these patients is high. The prognosis after transvenous lead extraction in Japanese patients, especially those with lead-related infective endocarditis, has not been evaluated. Then, the purpose of this study is to clarify the prognosis after transvenous lead extraction in Japanese patients with CIED-related infections at a single Japanese center., Methods: A total of 107 patients who underwent transvenous lead extraction were retrospectively reviewed. The patients were divided into a lead-related infective endocarditis group (n = 32) and a pocket infection group (n = 75). Procedure success rate and prognosis after lead extraction were evaluated between the two groups., Results: Procedure success rate was not significantly different between the groups. There were no deaths associated with the procedure or with infection. The survival rate was not significantly different at 1 year or at a median of 816 days (lead-related infective endocarditis vs pocket infection; 93.7% vs 94.7%, P  = 1.000; 78.1% vs 81.3%, P  = 0.791) Time to reimplantation and duration of hospital stay and antibiotics therapy were significantly longer for patients with lead-related infective endocarditis., Conclusion: In this study, the prognosis for patients with lead-related infective endocarditis after transvenous lead extraction was favorable. Thus, extraction should be strongly recommended, even if the general condition of the patient is poor., Competing Interests: Authors declare no conflict of interests for this article.

The failure rate of intrasynovial tendon repair is high due to substantial elongation at the repair site and to the development of adhesions between the tendon's surface and the surrounding digital sheath. To minimize these complications, we sought to reduce the incidence of gapping and to facilitate the initiation of early motion by improving the time zero structural properties of repair. The Winters-Gelberman 8-strand repair technique was modified by adding surface lock loops and by using Fiberwire suture material. Forty-eight canine flexor digitorum profundus tendons were transected and repaired with one of three 8-strand techniques (Pennington modified Kessler, half hitch loops, or surface locking Kessler) using either 3-0 Supramid or 4-0 Fiberwire suture. Biomechanical testing was performed to determine the physiologic and failure mode properties of the repairs. The surface locking Kessler technique improved repair maximum load, load necessary to create a 2 mm repair site gap, and yield force compared to the modified Kessler and half hitch loop techniques. Fiberwire suture improved maximum load, the load necessary to create a 2 mm repair site gap, stiffness, and yield force compared to Supramid suture. Failure occurred by both suture pull out and by suture breakage in the modified Kessler, Supramid suture repair group. Failure occurred consistently by suture breakage in the surface locking Kessler, Supramid suture repair group. These results reveal that a novel locking Kessler repair is significantly stronger than the current state-of-the art flexor tendon suture repair technique. The use of a surface locking Kessler technique with Fiberwire suture markedly improves the mechanical properties of intrasynovial tendon repair by reducing the risk of post-operative gapping and rupture., Competing Interests: The authors have declared that no competing interests exist.

Although malaria is not a common disease in Japan, malaria can be a mortal illness. The malaria rapid diagnostic immune-chromatographic test (ICT) enables a more rapid and easier diagnosis of malaria.

The detection of infective endocarditis (IE) of oral origin has been previously discussed. However, there are few reports confirming this infection using molecular biological techniques. We herein describe the case of a 67-year-old man who developed IE. Blood culture samples and strains obtained from the gingival and buccal mucosa showed 100% identity to Enterococcus faecalis JCM 5803 on sequencing of 16S rRNA gene fragments. A random amplification of polymorphic DNA (RAPD) analysis showed the same pattern for these samples, thus confirming the identity of E. faecalis isolates in the blood and oral mucosa. Our observations provide novel information regarding the level of identity between IE pathogens and oral bacteria.

The effect of antibiotics during the perioperative period of percutaneous dilatational tracheostomy (PDT) is still controversial. A total of 297 patients who underwent the PDT procedure were divided into 2 groups:those administered antibiotics perioperatively and those not administered antibiotics. Wound infections were noted in 7 cases (incidence rate, 2.36%) and no death was recorded. Of the 69 patients without antibiotics, 5 developed wound infections (incidence rate, 7.25%), while only 2 of the 228 patients with antibiotics developed wound infections (incidence rate, 0.88%) (p＝0.002;risk ratio, 8.82;95% confidence interval, 1.67-46.6). Of the 7 cases of wound infection, 5 cases occurred during the early period after PDT (within 7 days). Collectively, the present results suggest that prophylactic administration of antibiotics may prevent the incidence of PDT-induced wound infection, especially in the early phase after the PDT procedures. The need for antibiotics in PDT should be reconsidered.

We conducted a study on molecular epidemiology and clinical implications of metallo-beta-lactamase (MBL)-producing Pseudomonas aeruginosa isolated from urine. Over a 10-year period from 2001 through 2010, a total of 92 MBL-producing P. aeruginosa urine isolates were collected from patients (one isolate per patient) who were admitted to 5 hospitals in Okayama Prefecture, Japan. When cross-infection was suspected in the hospital, pulsed-field gel electrophoresis was performed. In the resulting dendrogram of 79 MBL-producing P. aeruginosa urine isolates, no identical isolates and 7 pairs of isolates with >80% similarity were found. The biofilm-forming capabilities of 92 MBL-producing P. aeruginosa urine isolates were significantly greater than those of 92 non-MBL-producing urine isolates in a medium of modified artificial urine. The imipenem resistance transferred in 16 of 18 isolates tested, and these frequencies were in the range of 10⁻³ to 10⁻⁹. All of 18 isolates tested belonged to internationally spread sequence type 235 and had 3 gene cassettes of antimicrobial resistance genes in the class 1 integron. The strong biofilm-forming capabilities of MBL-producing P. aeruginosa urine isolates could be seriously implicated in nosocomial infections. To prevent spread of the organism and transferable genes, effective strategies to inhibit biofilm formation in medical settings are needed.

We herein present the case of a 69-year-old Japanese man who had unprotected sexual contact with a local commercial sex worker in an East Asian country and was diagnosed as having disseminated gonococcal infection (DGI). The organism was confirmed to be Neisseria gonorrhoeae based on 16S rRNA sequencing and positive results for the cppB gene. This case indicates that a diagnosis of DGI should also be considered in elderly individuals. DGI potentially causes many complications, and the pathogen has recently been reported to be resistant to various antibiotics. Physicians must therefore pay more attention to the possible occurrence of DGI in various clinical settings.

Objective: The aim of this study was to determine the epidemiological characteristics of never-smoking patients with non-small cell lung cancer (NSCLC) detected with clinic-based screening programs, focusing on clinical risk factors and survival., Methods: The medical records of NSCLC patients (n=285) diagnosed at Fujisawa City Hospital between April 2000 and December 2010 with lesions that were originally detected with clinic-based screening programs in Fujisawa City were reviewed to identify the clinicopathological variables and survival outcomes., Results: Of the 285 NSCLC patients, 95 (33.3%) were never-smokers. A comparison between the never-smoking and ever-smoking patients revealed that the never-smokers included a significantly greater proportion of women and patients with adenocarcinoma (86.3% vs. 12.6%: p<0.001 or 94.7% vs. 55.8%: p<0.001, respectively). The overall survival rate of the never-smoking patients was significantly superior to that of the ever-smokers (p=0.004). In addition to smoking status, factors found to be significantly associated with the overall survival rate in univariate analyses were gender, stage, histology and first line treatment. A multivariate analysis revealed smoking status to be an independent prognostic factor in addition to stage and first line treatment., Conclusion: The differences in the clinicopathological factors and survival outcomes between never-smoking and ever-smoking patients with NSCLC detected with clinic-based screening programs suggest that persuading people to never start smoking is important.

A 27-year-old woman visited our hospital because of high fever. She had been diagnosed as 22q11.2 deletion syndrome (22q11.2DS) due to her cardiac history (tetralogy of Fallot), thymic hypoplasia and 22q11.2 deletion. She had a normal CD4/CD8 ratio, a slightly decreased lymphocyte count and normal serum immunoglobulin levels. Blood cultures were positive for Staphylococcus lugdunensis (S. lugdunensis). Infection route of S. lugdunensis in this case was unclear. The patient was successfully treated with several intravenous antibiotics. Infection should be considered when managing patients with 22q.11.2DS. regardless of whether their immune system is impaired.

Recently, the instance of beta-lactamase-negative ampicillin (AMP)-resistant (BLNAR) strains of Haemophilus influenzae has exhibited a marked increase in Japan. Our group determined the MICs of 160 clinical isolates of H. influenzae at a university hospital in Okinawa, the southernmost part of Japan, and found that 27 strains were BLNAR, while 24 strains were beta-lactamase-producing. Among the latter, 2 strains were resistant to AMP/clavulanic acid. BLNAR strains were shown to be more resistant to cephems than non-BLNAR strains. The competitive affinity assay using biotinylated AMP for penicillin-binding protein (PBP) showed that the binding of cefotiam to PBP 3A/3B of BLNAR strain C2163 was lower than that of the AMP-susceptible strain, while bindings to other PBPs were not changed. The sequences of ftsI, the gene encoding transpeptidase domain of PBP 3A and/or PBP 3B, were determined, and it was found that sequences of the ftsI gene of BLNAR strains were heterogeneous mutations. Deduced amino acid sequence analyses of BLNAR strains showed that three residues (Asn-526, Val-547, and Asn-569) were replaced with Lys, Ile, and Ser, respectively. In addition, some BLNAR strains had an additional three residues (Met-377, Ser-385, and Leu-389) in ftsI replaced with Ile, Thr, and Phe, respectively. Furthermore, changes from Asp-350 to Asn-350 and from Ser-357 to Asn-357 were also found in most BLNAR strains. These substitutions were located around the penicillin binding sites of PBP3. Multiple substitutions in the amino acid sequence seemed to be closely related with extended resistance against beta-lactams, including third-generation cephems. Randomly amplified polymorphism DNA fingerprinting of clinical isolates of BLNAR strains showed genetic heterogeneity of the strains, suggesting that the prevalence of BLNAR in this region was a result of the emergence of multiple clones of this phenotype.

Unlabelled: To examine the link between bone material properties and skeletal fragility, we analyzed the mechanical, histological, biochemical, and spectroscopic properties of bones from a murine model of skeletal fragility (SAMP6). Intact bones from SAMP6 mice are weak and brittle compared with SAMR1 controls, a defect attributed to reduced strength of the bone matrix. The matrix weakness is attributed primarily to poorer organization of collagen fibers and reduced collagen content., Introduction: The contribution of age-related changes in tissue material properties to skeletal fragility is poorly understood. We previously reported that bones from SAMP6 mice are weak and brittle versus age-matched controls. Our present objectives were to use the SAMP6 mouse to assess bone material properties in a model of skeletal fragility and to relate defects in the mechanical properties of bone to the properties of demineralized bone and to the structure and organization of collagen and mineral., Materials and Methods: Femora from 4- and 12-month-old SAMR1 (control) and SAMP6 mice were analyzed using bending and torsional mechanical testing of intact bones, tensile testing of demineralized bone, quantitative histology (including collagen fiber orientation), collagen cross-links biochemistry, and Raman spectroscopic analysis of mineral and collagen., Results: Intact bones from SAMP6 mice have normal elastic properties but inferior failure properties, with 60% lower fracture energy versus SAMR1 controls. The strength defect in SAMP6 bones was associated with a 23% reduction in demineralized bone strength, which in turn was associated with poorer collagen fiber organization, lower collagen content, and higher hydroxylysine levels. However, SAMP6 have normal levels of collagen cross-links and normal apatite mineral structure., Conclusions: Bones from SAMP6 osteoporotic mice are weak and brittle because of a defect in the strength of the bone matrix. This defect is attributed primarily to poorer organization of collagen fibers and reduced collagen content. These findings highlight the role of the collagen component of the bone matrix in influencing skeletal fragility.

The prevalence of hepatitis C virus (HCV) genotypes in Myanmar in comparison with the rest of Southeast Asia is not well known. Serum samples were obtained from 201 HCV antibody-positive volunteer blood donors in and around the Myanmar city of Yangon. Of these, the antibody titers of 101 samples were checked by serial dilution using HCV antibody PA test II and Terasaki microplate as a low-cost method. To compare antibody titers by this method and RNA identification, we also checked HCV-RNA using the Amplicor 2.0 test. Most high-titer groups were positive for HCV-RNA. Of the 201 samples, 110 were successfully polymerase chain reaction (PCR) amplified. Among them, 35 (31.8%) were of genotype 1, 52 (47.3%) were of genotype 3, and 23 (20.9%) were of type 6 variants, and phylogenetic analysis of these type 6 variants revealed that 3 new type 6 subgroups exist in Myanmar. We named the subgroups M6-1, M6-2, and M6-3. M6-1 and M6-2 were relatively close to types 8 and 9, respectively. M6-3, though only found in one sample, was a brand-new subgroup. These subtypes were not seen in Vietnam, where type 6 group variants are widely spread. These findings may be useful for analyzing how and when these subgroups were formed.

In studies of the pathogenesis of pancreatic fibrosis, pancreatic stellate cells (PSCs) have recently gained attention. In the present study, we established a new collagenase perfusion method through thoracic aorta cannulation to isolate PSCs, and we studied gene expression of TGF-beta1, type I collagen, and connective tissue growth factor using primary cultured PSCs. Our method facilitated PSC isolation, and by our new method, 4.3 +/- 1.2 x 10(6) PSCs were obtained from a rat. In comparing the expression of these genes with that of hepatic stellate cells (HSCs), we observed a similar pattern, although PSCs expressed type I collagen gene earlier than did HSCs. These results suggest that PSCs may play an important role in fibrosis of the pancreas, as HSCs do in liver fibrosis; in addition, PSCs may exist in a preactivated state or may be more easily activated than are HSCs. We also isolated the PSCs from a WBN/Kob rat, the spontaneous pancreatitis rat, and compared the gene expression with that from a normal rat.

The aim of this study is to explore the mechanisms of intratumoral cytogenetic heterogeneity (ICH) in pancreatic cancer. Using comparative genomic hybridization (CGH) analysis, we investigated interglandular variation in 20 primary invasive ductal adenocarcinomas of the pancreas. Three or four adjacent neoplastic glands were individually microdissected from a tumor specimen. Extracted DNA from each gland was amplified by degenerate oligonucleotide primed-PCR, followed by CGH. In addition, DNA index (DI) was measured by laser scanning cytometry in each case. CGH profiles displayed a wide variety of differences between glands within the same tumor in all cases, i.e., interglandular cytogenetic heterogeneity was distinct in pancreatic cancers. In this study, genetic changes detected in all regions of a tumor were classified as "region-independent" alterations, whereas changes seen in at least one, but not all regions were designated as "region-dependent" alterations, which resulted in ICH. The degree of ICH, which was manifested as the ratio of these two types of alterations, correlated closely with DI (Spearman rho = 0.842; P = 0.0002). Therefore, DI might be a surrogate marker for ICH. These results suggest that with tumor progression, ICH and DNA aneuploidy result from the successive appearance of region-dependent alterations attributable to chromosomal instability in tumor cells. Our data support a concept of individual cell heterogeneity in pancreatic cancer.

Comparative genomic hybridization (CGH) analysis of microscopic tumor samples is allowed by universal DNA amplification using degenerate oligonucleotide primed-PCR (DOP-PCR). To evaluate the reliablity of DOP-PCR CGH, we performed DOP-PCR CGH and standard CGH in parallel using DNAs extracted from 10 malignant tumors of the hepatobiliary tract and pancreas. Similar results were obtained by both methods with a few exceptions, indicating that DOP-PCR CGH provides cytogenetic information equivalent to that obtained from standard CGH. We also investigated the sensitivity of DOP-PCR CGH using sequential dilutions of DNA from microdissected tumor cells. DOP-PCR using 100 to 800 pg of template DNA yielded successful CGH results. However, less than 50 pg of template DNA was not suitable because of the small amount of generated DNA. These findings suggest that DOP-PCR CGH is applicable for CGH analysis of tiny specimens which are too small for standard CGH. Accordingly, DOP-PCR CGH analysis may become a useful method in clinical laboratory examination.

Antimicrobial susceptibility testing revealed among 150 clinical isolates of Streptococcus pneumoniae 4 pneumococcal isolates with resistance to fluoroquinolones (MIC of ciprofloxacin, >/=32 microgram/ml; MIC of sparfloxacin, >/=16 microgram/ml). Gene amplification and sequencing analysis of gyrA and parC revealed nucleotide changes leading to amino acid substitutions in both GyrA and ParC of all four fluoroquinolone-resistant isolates. In the case of strains 182 and 674 for which sparfloxacin MICs were 16 and 64 microgram/ml, respectively, nucleotide changes were detected at codon 81 in gyrA and codon 79 in parC; these changes led to an Ser-->Phe substitution in GyrA and an Ser-->Phe substitution in ParC. Strains 354 and 252, for which sparfloxacin MICs were 128 microgram/ml, revealed multiple mutations in both gyrA and parC. These strains exhibited nucleotide changes at codon 85 leading to a Glu-->Lys substitution in GyrA, in addition to Ser-79-->Tyr and Lys-137-->Asn substitutions in ParC. Moreover, strain 252 showed additional nucleotide changes at codon 93, which led to a Trp-->Arg substitution in GyrA. These results suggest that sparfloxacin resistance could be due to the multiple mutations in GyrA and ParC. However, it is possible that other yet unidentified mutations may also be involved in the high-level resistance to fluoroquinolones in S. pneumoniae.

We developed a new simple assay for the quantitation of the activities of drugs against intracellular Legionella pneumophila. The cells of a murine macrophage-like cell line (J774.1 cells) allowed the intracellular growth and replication of the bacteria, which ultimately resulted in cell death. The infected J774.1 cell monolayers in 96-well microplates were first treated with antibiotics and were further cultured for 72 h. The number of viable J774.1 cells in each well was quantified by a colorimetric assay with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and an enzyme-linked immunosorbent assay reader. The number of growing bacteria in each well was also determined by counting the numbers of CFU on buffered charcoal yeast extract-alpha agar plates. Viable J774.1 cell counts, determined by the colorimetric assay, were inversely proportional to the number of intracellular replicating bacteria. The minimum extracellular concentrations (MIECs) of 24 antibiotics causing inhibition of intracellular growth of L. pneumophila were determined by the colorimetric assay system. The MIECs of beta-lactams and aminoglycosides were markedly higher than the MICs in buffered yeast extract-alpha broth. The MIECs of macrolides, fluoroquinolones, rifampin, and minocycline were similar to the respective MICs. According to their intracellular activities, clarithromycin and sparfloxacin were the most potent among the macrolides or fluoroquinolones tested in this study. Our results indicated that the MTT assay system allows comparative and quantitative evaluations of the intracellular activities of antibiotics and efficient processing of a large number of samples.

The presence of Legionella spp. in cooling tower water was investigated by using the polymerase chain reaction. Total Legionella spp. detection was performed with 20-mer 5S rRNA complementary DNA sequence primers, and specific Legionella pneumophila detection was performed with 20-mer and then 21-mer macrophage infectivity potentiator gene sequence primers. Of 27 cooling tower water samples, 25 were positive for Legionella spp., and 14 of these contained L. pneumophila.