Hrisi Bahar

Antimicrobial Resistance and β-Lactamase Production of Clinical Isolates of Prevotella and Porphyromonas Species

Background: This study determined the β-lactamase production and the antimicrobial resistance of 72 Prevotella species and 48 Porphyromonas species isolated from different clinical specimens. Methods: All strains were identified using API 32 ID. The β-lactamase production was determined by nitrocefin disks. E test strips of benzylpenicillin, ampicillin + sulbactam, cefoxitin, clindamycin, metronidazole and imipenem were tested for each strain. Results: Nineteen Prevotella melaninogenica, 18 Prevotella intermedia, 16 Prevotella denticola, 11 Prevotella loescheii and 8 Prevotella bivia strains were identified. Four wereclindamycin resistant. The highest β-lactamase production was found at a rate of 68.4% in P. melaninogenica species. Additionally, 33 Porphyromonas asaccharolytica and 15 Porphyromonas gingivalis strains were identified. None of them produced β-lactamase. Conclusion: In view of the emerging antibiotic resistance among anaerobes, the current local susceptibility profile of our Prevotella and Porphyromonas species will establish the basis for additional surveys tracing significant changes in the antimicrobial resistance of our clinical isolates.

Microbial Changes in Conjunctival Flora with 30-day Continuous-wear Silicone Hydrogel Contact Lenses

Purpose. To determine the effect of 30-day continuous-wear silicone hydrogel contact lenses on the conjunctival flora in asymptomatic wearers. Methods. The authors studied 29 eyes of 15 patients wearing Focus NIGHT & DAY silicone hydrogel contact lenses for up to 30 nights of continuous wear. The average age of the patients was 25.54 ± 8.98 years. Cultures of the inferior cul-de-sac were taken bilaterally from all eyes, before and after lens wear in asymptomatic patients. The isolation and identification of bacteria were made by standard clinical laboratory methods. Results. The number of eyes whose conjunctival cultures were sterile before using the lenses significantly decreased (P = 0.0005), and the number of eyes with a growth of coagulase-negative staphylococci and diphtheroid rods in their conjunctival cultures significantly increased after using these lenses (P = 0.001 and P = 0.031, respectively). Conversely, a statistically significant difference was not found in the number of eyes that carried Propionibacterium acnes and Fusobacterium nucleatum in their conjunctival cultures before and after using the 30-day continuous-wear silicone hydrogel lenses (P = 0.998 and P = 0.488, respectively). Conclusions. The results suggest that the sterility of the conjunctiva significantly decreased after using 30-day continuous-wear silicone hydrogel contact lenses. In addition, the number of bacteria of the normal conjunctival flora significantly increased after the use of these lenses. Contamination by the bacteria of the eyelids may be a possible colonization factor in this study group. Therefore, it is appropriate to examine the patients who wear these lenses more frequently.

The detection of occult HBV infection in patients with HBsAg negative pattern by real-time PCR method

AIM Diagnostic problems may be encountered in Hepatitis B virus (HBV) infections by serological tests and HBV DNA can be detectable in plasma and liver tissue while the HBsAg test is negative. This situation can be defined as occult or isolated Anti-HBc infections. Occult HBV infections may be divided into two categories by using hepatitis markers. One of them being that all hepatitis markers are negative and the other situation is having Anti-HBc +/- and Anti-HBs+patterns. These situations can be seen in isolated Anti-HBc cases. METHOD In this study, we aimed to detect the ratio of occult HBV infections by investigating HBV DNA in four different groups. These groups are: (1) 20 isolated Anti-HBc positive individuals, (2) 23 individuals naturally immune to HBV infection, (3) 20 individuals with seronegative hepatitis markers and high ALT levels, and (4) 23 vaccinated individuals against HBV. In order to detect HBV DNA the real-time PCR kit (QIAGEN, Artus HBV RG PCR Kit, Germany) with high analytical sensitivity (≤3.8IU/ml) was used. RESULTS The reliability of the molecular methods was assessed by increasing the quantitation standards of internal, external and also positive controls. No HBV DNA was detected in any of the 86 individuals consisting of four study groups. CONCLUSION In conclusion, we did not detect occult HBV infection in our four study groups by using a high sensitivity real-time (RT) PCR method, while occult HBV infections with various frequencies were detected in other large, serial international studies in which highly sensitive analytical molecular methods were used. Although we also used a high standard molecular kit to detect occult HBV infections, we suggest that the reason for the absence of detection of occult HBV infections may be due to the small number of cases included in this study. However, it was assumed that the use of a nucleic acid amplification technology (NAT) with high analytical sensitivity in blood banks to prevent HBV transmission by blood transfusion is controversial due to both costs and diagnostic efficacy and for this reason we suggest that it will be useful to perform large serial studies regarding occult HBV infections in the future.

Haemophilus influenzae type b antibodies in vaccinated and non‐vaccinated children

Background: Invasive Haemophilus influenzae type b (Hib) infection has a high morbidity among young children, but the burden of disease and rate of Hib are different in different regions. The aim of the present study was to investigate the levels of Hib antibodies and the oropharyngeal Hib prevalence in young children.

Pharyngeal Carriage and Antimicrobial Resistance of Haemophilus influenzae in Non-Type-b-Vaccinated Healthy Children Attending Day Care Centers in Turkey

Background: The true prevalence of Haemophilus influenzae carriage rates in Turkey is unknown. As surveillance of pharyngeal carriage of resistant strains is important for initiating adequate empirical antimicrobial therapy, with the present study, we aimed to determine the carriage rates and antimicrobial resistance patterns of H. influenzae isolated from healthy children attending day care centers (DCCs) in Istanbul, Turkey. Methods: A total of 195 healthy children were included from two DCCs. Pharyngeal swabs were cultured for H. influenzae which were identified according to standard microbiologic procedures. Antimicrobial susceptibility tests were performed by the agar dilution method in accordance with the guidelines of the National Committee for Clinical Laboratory standards. β-Lactamase production was determined by the nitrocefin disc test. Results: The average pharyngeal carriage rate of H. influenzae was determined as 48.7%: 7.2% type b, 7.6% other capsulated strains, 33.9% noncapsulated strains, with a carriage peak between 0 and 11 months (68.1%). The ampicillin resistance observed in 7.3% of H. influenzae isolates was associated with a presence of β-lactamase, except for one isolate which was interpreted as β-lactamase-negative ampicillin-resistant strain. The resistance of H. influenzae to sulbactam/ampicillin, cefuroxime, azithromycin, tetracycline and cotrimoxazole was 0.5, 1.5, 0.5, 2.9 and 28.6%, respectively. Cefotaxime, ceftriaxone, ciprofloxacin and imipenem resistance was not detected. Conclusion: Our data show that the upper respiratory tract of about 48.7% of children was colonized with H. influenzae. This high colonization rate indicates that there is a need for surveillance of pharyngeal carriage of resistant strains in healthy Turkish children attending DCCs.

Primary actinomycosis of the hand: A case report and literature review

A 35-year-old male was admitted to the hospital because of a 6-month history of increasing pain, swelling with erythema, and indurated nodules with intermittent discharge on the dorsum and palmar surface of his right hand. The swelling did not interfere with the normal use of his hand. The patient could not recall any specific incident prior to the onset of the swelling and had not taken antibiotics during this period. Results of the physical examination were normal except for dorsal and palmar swelling and erythema over the second, third, and fourth metacarpals of the right hand. There were three nodules associated with fluctuante surrounded by enduration (Figure 1). No lymphadenopathy in the relevant lymph drainage areas was detected. Results of laboratory investigations revealed a white blood cell count of 8.7 X 109/L; hemoglobin of 150 g/L; erythrocyte sedimentation rate of 10 mm/h (Westergren method); and a C-reactive protein of 3 mg/L (normal value: O-5 mg/L). Radiography and magnetic resonance imaging (MRI) of the right hand showed changes

Oropharyngeal flora changes after tonsillectomy

Objective: We aimed to investigate the effect of tonsillectomy on oropharyngeal flora in children who underwent tonsillectomy for chronic recurrent tonsillitis. Study Design and Setting: A prospective study was performed comprising patients with chronic recurrent tonsillitis who underwent tonsillectomy at the Department of Otolaryngology, Cerrahpasa Medical School. Incisional core biopsies of excised tonsils were also performed. Swabs and core biopsy specimens were transferred and maintained in Stuarts medium and sent to the Department of Microbiology and Clinical Microbiology at Cerrahpasa Medical School for microbiologic evaluation. Subjects and Methods: Oropharyngeal swabs and tonsillar core biopsy specimens from 31 patients operated on for recurrent tonsillitis were cultured. Follow-up oropharyngeal swabs were cultured one month after tonsillectomy. Results: There was no significant difference between the preoperative and postoperative isolation rate of the potentially pathogenic bacteria. Normal aerobic flora did not change significantly. However, the isolation rate of the Neisseria species dropped (P = 0.097) but did not reach statistical significance. Among anaerobes, Bacteroides fragilis, one of the major anaerobic bacteria, dropped significantly (P = 0.007). The Propionibacterium acnes isolation rate increased significantly (P = 0.009). Conclusion: Oropharyngeal anaerobic bacterial flora decreases after tonsillectomy in recurrent tonsillitis patients. The isolation rate for bacteria of the normal flora and potentially pathogenic bacteria does not change. Tonsils with recurrent infections may become a nidus for anaerobic bacteria. In patients with chronic recurrent tonsillitis, tonsillectomy may help change anaerobic bacterial oropharyngeal flora to the normal flora found in healthy individuals.

Microbiologic evaluation of frequent-replacement soft contact lenses

PURPOSE This article reports a microbiologic study of two kinds of monthly frequent-replacement daily wear soft contact lenses, with different amounts of water content, in asymptomatic contact lens wearers. METHOD We studied 35 lenses of 18 patients who wear frequent-replacement soft contact lenses with a water content of 38% and 40 lenses of 20 patients using frequent-replacement contact lenses with a water content of 55%. The lenses worn by patients regularly for 1 month were removed from their eyes in a sterile manner on the 30th day and were studied microbiologically to isolate pathogenic agents. RESULTS In the group of monthly frequent-replacement soft contact lenses with a water content of 38%, microorganisms were isolated at a rate of 91%; and in the group of monthly frequent-replacement soft contact lenses with a water content of 55%, microorganisms were isolated at a rate of 85%. When the two groups were compared, there was no statistically significant difference (P=0.31). Although coagulase-negative staphylococci, Corynebacterium spp, and gram-negative rods were detected in both groups, Staphylococcus aureus, non-hemolytic streptococci, Neisseriae spp, and Penicillium spp also were isolated in the group with the higher water content. CONCLUSION Bacteria spreading from the environment or from skin flora to the eyes showed more diversity in the group of frequent-replacement soft contact lenses with a high water content. Additionally, Penicillium spp also was isolated in this group. Therefore scrupulous attention to daily lens care is crucial for people who wear frequent-replacement soft contact lenses.

Lymphocyte subgroups and natural killer cell activity in recurrent herpetic stromal keratitis.

Purpose. Although the role of natural killer cells in the defense against certain viral infections has been published, little is known about the role of lymphocyte subgroups in recurrent herpetic stromal keratitis. Accordingly, serum levels of major immunoglobulins (IgG, IgA, and IgM) and IgG subgroups, the lymphocyte subgroups, and natural killer cell activity were investigated in patients with recurrent herpetic stromal keratitis. Methods. Eleven patients with recurrent herpetic stromal keratitis and 10 healthy subjects were included. A delayed-type hypersensitivity skin test was performed in addition to the determination of serum immunoglobulin levels, IgG subgroups, peripheral blood lymphocyte percentages, and natural killer cell activity in both groups. Results. The result of the delayed-type hypersensitivity skin test was positive in all patients with recurrent herpetic stromal keratitis and healthy subjects. No significant difference was obtained in serum immunoglobulin levels and IgG subgroups between the patients and healthy subjects. Among the cell surface antigens (CD3, CD4, CD8, CD16, CD19, and CD20), only CD8+ (i.e., cytotoxic) T-lymphocyte percentages were significantly increased (P=0.003), and the CD4:CD8 ratio was significantly decreased in the patients compared to the healthy subjects (P=0.021). There was no significant difference in the expression of CD16+ natural killer cells between both groups, despite a significantly lower natural killer cell activity in patients with recurrent herpetic stromal keratitis (P=0.011). Conclusions. These results indicate that human cytotoxic T cells show a difference in numbers and natural killer cell activity that may affect the prognosis of recurrent herpetic stromal keratitis.