Home About us Contact
|
Home About us Contact | ||
|
|
||
Culture Negative (culture + negative)
Selected AbstractsInfectious keratitis related to orthokeratologyOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 2 2006Xuguang Sun Abstract Purpose:, To report 28 cases of infectious keratitis related to orthokeratology lens overnight wear in China. Methods:, From March 2000 to August 2001, 28 cases of infectious keratitis related to overnight orthokeratology lens wear were diagnosed in Beijing Institute of Ophthalmology. These were retrospectively reviewed with regard to the pathogens isolated, duration of wear, the time since onset of symptoms, and age. Cultures of corneal scrapes for bacteria, fungus and Acanthamoeba were performed in all of the 28 cases. Results:, All cases were students, including 10 males and 18 females, average age was 16 years (range 10,21 years). The duration of orthokeratology overnight wearing was from 2 weeks to 2 years. Uncorrected visual acuity (UCVA) on initial examination in our institute was from 20/200 to light perception. Of 28 isolates, 24 were culture positive (including 11 bacteria, 11 Acanthamoeba and two fungi), and four were culture negative. In two of the four culture negative cases, Acanthamoeba cysts were detected in the corneal stroma with the confocal microscope. Acanthamoeba and Pseudomonas aeruginosa accounted for 75% (21 of 28) of the cases of infectious keratitis. Conclusion:, Infectious keratitis is a severe complication associated with overnight orthokeratology lens wear. Ophthalmologists should pay more attention to this complication in practice. [source] Persistence of borrelial DNA in the joints of Borrelia burgdorferi -infected mice after ceftriaxone treatmentAPMIS, Issue 9 2010HETA YRJÄNÄINEN Yrjänäinen H, Hytönen J, Hartiala P, Oksi J, Viljanen MK. Persistence of borrelial DNA in the joints of Borrelia burgdorferi -infected mice after ceftriaxone treatment. APMIS 2010; 118: 665,73. We have earlier shown that Borrelia burgdorferi -infected and ceftriaxone-treated mice have viable spirochetes in their body, since immunosuppressive treatment allows B. burgdorferi to be detected by culture. However, the niche of the persisting spirochetes remained unknown. In the present study, we analyzed the tissues of B. burgdorferi -infected and ceftriaxone-treated mice by culture and PCR to reveal the foci of persisting spirochetes. C3H/HeN mice were infected via intradermal needle injection with B. burgdorferi s.s. N40. The mice were treated as follows: (i) short (5 days) and (ii) long (18 days) course of ceftriaxone at 2 weeks of infection and killed after either 10 or 30 weeks, or (iii) the mice received ceftriaxone for 5 days at 18 weeks of infection and were killed 21 weeks after the treatment. All samples of ceftriaxone-treated mice were culture negative, whereas all untreated controls were culture positive. Importantly, B. burgdorferi DNA was detected in the joints of 30,100% of the treated mice. In conclusion, these results combined with earlier results suggest that the joint or a tissue adjacent to the joint is the niche of persisting B. burgdorferi in ceftriaxone-treated mice. [source] Topical application of acidified nitrite to the nail renders it antifungal and causes nitrosation of cysteine groups in the nail plateBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2007M.J. Finnen Summary Background, Topical treatment of nail diseases is hampered by the nail plate barrier, consisting of dense cross-linked keratin fibres held together by cysteine-rich proteins and disulphide bonds, which prevents penetration of antifungal agents to the focus of fungal infection. Acidified nitrite is an effective treatment for tinea pedis. It releases nitric oxide (NO) and other NO-related species. NO can react with thiol (-SH) groups to form nitrosothiols (-SNO). Objectives, To determine whether acidified nitrite can penetrate the nail barrier and cure onychomycosis, and to determine whether nitrosospecies can bind to the nail plate. Methods, Nails were treated with a mixture of citric acid and sodium nitrite in a molar ratio of 0·54 at either low dose (0·75%/0·5%) or high dose (13·5%/9%). Immunohistochemistry, ultraviolet-visible absorbance spectroscopy and serial chemical reduction of nitrosospecies followed by chemiluminescent detection of NO were used to measure nitrosospecies. Acidified nitrite-treated nails and the nitrosothiols S-nitrosopenicillamine (SNAP) and S-nitrosoglutathione (GSNO) were added to Trichophyton rubrum and T. mentagrophytes cultures in liquid Sabouraud medium and growth measured 3 days later. Thirteen patients with positive mycological cultures for Trichophyton or Fusarium species were treated with topical acidified nitrite for 16 weeks. Repeat mycological examination was performed during this treatment time. Results, S-nitrothiols were formed in the nail following a single treatment of low- or high-dose sodium nitrite and citric acid. Repeated exposure to high-dose acidified nitrite led to additional formation of N-nitrosated species. S-nitrosothiol formation caused the nail to become antifungal to T. rubrum and T. mentagrophytes. Antifungal activity was Cu2+ sensitive. The nitrosothiols SNAP and GSNO were also found to be antifungal. Topical acidified nitrite treatment of patients with onychomycosis resulted in > 90% becoming culture negative for T. rubrum. Conclusions, Acidified nitrite cream results in the formation of S-nitrosocysteine throughout the treated nail. Acidified nitrite treatment makes a nail antifungal. S-nitrosothiols, formed by nitrosation of nail sulphur residues, are the active component. Acidified nitrite exploits the nature of the nail barrier and utilizes it as a means of delivery of NO/nitrosothiol-mediated antifungal activity. Thus the principal obstacle to therapy in the nail becomes an effective delivery mechanism. [source] Community-acquired Pneumonia in North American Emergency Departments: Drug Resistance and Treatment Success with ClarithromycinACADEMIC EMERGENCY MEDICINE, Issue 7 2007Brian H. Rowe MD Background:Limited information on antibiotic resistance of Streptococcus pneumoniae (SP) exists for patients discharged from emergency departments with community-acquired pneumonia. Objectives:Using a standardized collection process, this study examined sputum microbiology in outpatient community-acquired pneumonia. Methods:This was a multicenter, prospective cohort study conducted in North American emergency departments between December 2001 and May 2003. Thirty-one emergency departments enrolled patients older than 18 years with a Pneumonia Severity Index of I to III. All patients received oral clarithromycin and were followed up for four weeks. SP resistance to macrolides and penicillin was determined by a central laboratory. Results:Among the 317 cultured sputum samples, 116 (37%; 95% confidence interval [CI] = 32% to 42%) grew an identifiable organism; 74 (23% of cultured cases; 95% CI = 19% to 28%) grew non-SP organisms and 42 grew SP organisms (SP positive; 13% of cultured cases; 95% CI = 10% to 17%). A total of 13 resistant organisms (4% of cultured cases; 95% CI = 2% to 6%) were identified. Resistance to macrolides occurred in nine patients (3% of cultured cases [95% CI = 1% to 5%]; 24% of SP-positive cases [95% CI = 11% to 37%]); and resistance to penicillin occurred in nine patients (3% of all sputum-positive cases [95% CI = 1% to 5%]; 21% of SP-positive cases [95% CI = 9% to 34%]). The four-week cure rates were similar in both groups. Conclusions:Among outpatients with community-acquired pneumonia, half produced adequate sputum samples and most were culture negative. SP resistance was similar to rates from large national databases, and results were of little (if any) consequence. In low-risk Pneumonia Severity Index cases, sputum cultures should not be collected routinely. [source] Endophthalmitis in the western Sydney region: a case-control studyCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 6 2001Somsak Lertsumitkul FRACO ABSTRACT Background: A retrospective case-control study was conducted to investigate risk factors for endophthalmitis following routine intraocular surgery. Methods: A review was performed of consecutive cases of endophthalmitis from three teaching hospitals in the western Sydney region and matched controls from the same institutions between 1996 and 1998. Results: There were 31 cases and 66 controls. Eighty procedures were phacoemulsification, 15 conventional extracapsular cataract extraction, and two were penetrating keratoplasties. Of the 80 patients who had phacoemulsification surgery, 50 had a clear corneal incision, and 26 had a scleral incision (four were unknown). Logistic regression showed an increased risk of endophthalmitis with surgical complications (P = 0.002) and clear cornea temporal incisions (P = 0.007). Risk of endophthalmitis was reduced with use of subconjunctival injections (P = 0.008). The yield for the Gram stain was 47% and for culture was 67%. Anterior chamber tap in addition to vitreous biopsy alone did not increase the yield for microorganism (P = 0.78). Mean visual acuity on presentation was hand movement with 13 patients (50%) showing visual improvement following intravitreal injections of antibiotics (P = 0.003). Visual prognosis did not correlate with presenting visual acuity but appeared to be better in those who grew Staphylococcus epidermidis or were culture negative. Conclusions: Although this study is unable to draw definite conclusions regarding risk of endophthalmitis in clear corneal temporal cataract surgery, sufficient data suggest the importance of incision type and location. Surgical complication is an important risk factor for endophthalmitis. Use of subconjunctival antibiotic injections at the conclusion of the procedure is recommended. [source] | ||||||||||