The usefulness of semi-solid medium in the isolation of highly virulent Leptospira strains from wild rats in an urban area of Fukuoka, Japan.

Leptospirosis is a worldwide zoonosis. The importance of urban leptospirosis is recognized in Japan: urban rats carry pathogenic leptospires and people acquire these pathogens through contact with surface water or soil contaminated by the urine of the infected animals. To determine the current Leptospira carriage rate in urban rats, 29 wild rats were trapped in the central area of Fukuoka and strains isolated from their kidneys and urine analyzed. When semi-solid Korthof's medium containing 0.1% agar was used for isolation, 72.2% and 30.8% of the kidney and urine cultures, respectively, were found to be Leptospira-positive. The isolates belonged to Leptospira interrogans, and were classified into two groups (serogroups Pomona and Icterohaemorrhagiae) based on the results of gyrB sequence analysis and microscopic agglutination testing (MAT). Strains belonging to serogroup Icterohemorrhagiae grew well in liquid medium. On the other hand, serogroup Pomona isolates multiplied very little in liquid medium, but did grow in a semi-solid medium. Although strains belonging to serogroup Pomona have not been recognized as native to Japan, this strain may be widely distributed in urban rats. Representative strains from each group were found to be highly pathogenic to hamsters. Our findings should serve as a warning that it is still possible to become infected with leptospires from wild rats living in inner cities of Japan. Furthermore, the use of semi-solid medium for culture will improve the isolation rate of leptospires from the kidneys of wild rats.

Molecular Identification of Mycobacterium leprae in the Leprosy Patients.

BACKGROUND: Several discoveries about leprosy indicate that Mycobacterium leprae transmission mainly occurs by inhalation, and the nose is a major port of entry and exit. Molecular probes have shown certain potential for the detection and identification of M. leprae in patients. The aim of this study was to identify M. leprae in nasal swab specimens using polymerase chain reaction (PCR)-based assays followed by gene sequencing methods. This observational study examines 64 anterior nasal swab samples taken from pretreatment leprosy patients, on-treatment and completed leprosy treatment in Bulukumba, South Sulawesi, Indonesia. METHODS: samples were analyzed by molecular detection methods according to the standard methods at the Clinical Microbiology Laboratory of Hasanuddin University. Descriptive statistics were utilized to summarize patient demographics and outcomes. RESULTS: This study uses PCR to detect the M. leprae deoxyribonucleic acid (DNA) from nasal swab specimens. Data were collected from 64 patients with a percentage of male patients 51.54%. Based on the age category, the group 45-46 years was the most frequent (39.05%). PCR detection proline-rich antigen gene of a 531 bp DNA fragment from M. leprae, was positive in eight patients, and they were multibacillary. Furthermore, PCR was positive in 5 (31.25%) of 16 new leprosy patients, 2 (8.69%) of 23 on-treatment patients, and 1 (4%) of 25 treatment completed patients. Based on the results of the phylogenetic tree and analysis of 8 positive results detected by M. leprae from leprosy patients, almost all samples have a level of similarity, except for sample Ua7. CONCLUSIONS: M. leprae cannot grow in vitro, so molecular diagnostic tools were used to confirm the disease. This study predominantly of males with the age above 45 years of age being the most common. Eight M. leprae were positive from nasal swab leprosy patients. The sequencing findings provide insight into the genetic diversity of the genus M. leprae, so it is necessary to consider the detection of whole-genome sequence.

Molecular identification of mycobacterial infections in nonsputum specimens.

Background: Mycobacterial infections can manifest in various anatomical sites, necessitating the analysis of nonsputum specimens for accurate diagnosis. The aim of this study was to identify the molecular cases of mycobacterial infections in nonsputum specimens using polymerase chain reaction based assays and gene sequencing methods. Methods: This observational study examined 161 nonsputum samples that have been stored in the Clinical Microbiology Laboratory at Hasanuddin University Hospital. Samples were analyzed by microscopy and molecular detection methods according to the standard methods at the Clinical Microbiology Laboratory of Hasanuddin University. Descriptive statistics were utilized to summarize patient demographics, infection characteristics, and outcomes. Results: The samples were collected from patients with an average age of 39.82 years. The anatomical sites of specimen collection varied, with musculoskeletal organs and eyes being the most common. Microbiological analysis revealed a predominance of Gram positive bacteria, with polymicrobial morphology observed. Methicillin susceptible Staphylococcus aureus were the most frequently isolated organisms. Acid fast bacilli were detected in 8.1% of samples. Phylogenetic analysis, based on 16S rRNA gene sequencing, revealed similarities between the samples and known mycobacterial species, including Mycobacterium parmense, Mycobacterium lacus, and Mycobacterium dioxanotrophicus. Conclusions: The findings highlight the microbial diversity observed in these infections. The study advocates for comprehensive diagnostic evaluations and targeted testing strategies based on both clinical and laboratory findings. This knowledge can contribute to improved diagnostic accuracy and optimized treatment strategies for mycobacterial infections.

A Streptococcus suis infection causing pneumonia in Indonesia: A case report.

Streptococcus suis (S. suis) is a zoonotic pathogen that causes pneumonia, sepsis, endocarditis, and meningitis. S. suis is primarily found in the upper respiratory tract of pigs. To our knowledge, the first case of S. suis infection has resulted in pneumonia in Indonesia. A 40-year-old woman suffered from shortness of breath last month. The complaint worsened one week ago. She also complained of a productive cough with thick white phlegm. She has a history of late-stage cervical cancer. The patient's vital signs were normal, except for tachypnea. Vesicular breath sounds, no wheezing, and coarse lung crackles were discovered during a physical examination. A chest x-ray showed patchy airspace opacities and interstitial thickening throughout both lungs. The following results were obtained from routine laboratory leukocytosis. Gram stain of the sputum showed a few Gram-positive cocci, mostly in pairs. We confirmed this finding by performing the blood agar, and chocolate agar revealed small α-hemolytic and catalase-negative colonies. The strain was positive for penicillin and ceftriaxone in antimicrobial susceptibility testing. A combination of penicillin and ceftriaxone intravenous was utilized for definitive treatment. After completing a 14-day course of oral antibiotic medication, the patient was discharged. Her symptoms had subsided. This case should remind physicians about the possibility of cancer associated with S. suis infected patient and no clear history of exposure to pigs or other animals.

Characterization of Leptospira infection in suckling and weaning rat pups.

Rats are known to be the most important reservoirs of Leptospira spp. However, the leptospiral dose and age at which rats become resistant to Leptospira infection are not yet well elucidated. Aimed to characterize leptospirosis in rat pups, we found that suckling pups (4-, 7-, and 14-day old) are susceptible to leptospires and resistance starts from the weaning age (23-day old). Susceptibility of rat pups was also affected by the infecting dose of the organisms. Jaundice, decrease in body weight, and neurological symptoms prior to moribundity was evident in infected suckling pups. However, 23-day-old infected pups did not manifest any pathological changes and were able to survive the infection similar to adult rats. Based on these results, we propose the suckling rat pup as a novel animal model of human leptospirosis to investigate pathogenesis, development of host resistance, and the mechanisms involved in rats becoming maintenance hosts for leptospires.