Clinically important resistance of fungal pathogens to azole antifungal drugs is most frequently caused by the over-expression of energy-dependent drug efflux pumps. These pumps usually belong to either the ATP-binding cassette (ABC) family or the Major Facilitator Superfamily (MFS) class of membrane transporter. Little is known about how these pumps work and there is an urgent need to develop pump antagonists that circumvent azole resistance. We have developed a protein hyper-expression system to facilitate functional analysis of efflux pumps based on a Saccharomyces cerevisiae host which has been deleted in seven major ABC transporters to reduce the background of endogenous efflux activity. Plasmid pABC3 was engineered to allow functional hyper-expression of foreign proteins in this host. The main advantages of the system include its ease of directional cloning and the use of homologous recombination to stably integrate single copy constructs into the host genome under the control of a highly active transcriptional regulator. The system has been used to clone and functionally hyper-express genes encoding drug efflux pumps from several pathogenic fungi. Furthermore, the protein hyper-expression system has been used to screen for pump inhibitors and study the structure and function of heterologous membrane proteins.

Cholera continues to be an important public health problem among many poorer communities. In order to determine the epidemiology of Vibrio cholerae in southeastern Iran, 3,594 patients with watery diarrhea, who were referred to the hospitals from Zabol city and 45 neighboring rural populations of Sistan-Blouchestan province, were investigated over a period of 6 years (1997 - 2002). V. cholerae strains were isolated from 362 samples (10.07%). Isolation of V. cholerae in this sample decreased from 22.47% in 1997 to 0% in 2002. Individuals of all ages and social and economic strata were affected. Among the patients with cholera in the present study, only 24 (6.6%) lived in an urban area; 270 (74.6%) of the patients had been referred from rural areas, and the remaining 68 (18.8%) were from neighboring Afghanistan. V. cholerae O1 Ogawa and NAG vibrios were found in 92.8 and 7.2% of patients, respectively. Among the 362 samples, 244 were collected from inpatients and 118 were from outpatients. Twelve of these patients died because of the severity of their disease, severe dehydration and electrolytes imbalance. The priorities for cholera control remain public health interventions through improved water and sanitation, improved surveillance and access to health care facilities, and further development of appropriate vaccines.

Activation of macrophages represents one of the initial events in innate immunity to intracellular infections. CD14 is expressed principally by cells of monocyte/macrophage lineage and plays a pivotal role in innate recognition of bacterial cell wall components, particularly lipopolysaccharides. We measured serum concentrations of soluble CD14 (sCD14) in serum samples obtained from 37 patients with brucellosis and 36 healthy controls. Serum levels of sCD14 were significantly increased in patients with brucellosis compared with those in healthy controls (P < 0.001). Re-analysis of serum samples after treatment in 25 patients demonstrated that treatment did not result in any significant decline in sCD14 levels. Despite a limited study population, these findings may implicate CD14 signaling as an important component of the initial anti-brucellar host response and suggest that activation of mononuclear phagocytic system is sustained even following effective treatment.

Although hepatitis B has been well studied, there are still aspects of its epidemiology that remain to be clarified. There are many regions with high seroprevalence, particularly in the developing regions of the world, and these regions are known to have different epidemiologic patterns. Nonetheless, there are currently no data on the differences in hepatitis B seroprevalence between urban and rural areas of Turkey. In the present study, therefore, we used 30-cluster sampling to determine and compare the prevalence of hepatitis B in the urban and rural areas of the least developed region of Turkey, the southeastern region. From 2,888 adults living in the region, blood samples were obtained from house visits, and screened for HBsAg, anti-HBs, and anti-HBcIgG. Factors associated with hepatitis B seroprevalence, particularly living in rural areas, were analyzed with multivariate methods. The seroprevalence of HBsAg was 8.2% in the rural and 6.2% in the urban areas. There was a statistically significant difference between urban and rural regions in terms of HBsAg positivity (crude OR: 0.74; 95% CI: 0.55 - 0.98). Exposure to hepatitis B virus (HBV) increased with age both in urban and rural areas. Lower education level was also an important risk factor for hepatitis B seropositivity in urban areas (adjusted OR: 1.66; 95% CI: 1.26 - 2.19) but not in rural ones (adjusted OR: 0.77; 95% CI: 0.36 - 1.69). Familial jaundice history was a statistically significant risk factor for HBsAg positivity in rural areas (adjusted OR: 2.15; 95% CI: 1.30 - 3.56) but not in urban ones (adjusted OR: 1.48; 95% CI: 0.96 - 2.27). This study shows that the prevalence of HBV infection in the southeastern region of Turkey is intermediate among the levels reported for the European region of the World Health Orgnization.

Antimicrobial susceptibilities of 156 Streptococcus pneumoniae strains isolated from 1994 through 2002 were studied. Of this total, 38.7, 26.3, 16.7, 8.9, and 9.6% were recovered from patients with bacteremia, pneumonia, otitis media, sinusitis, and meningitis, respectively. All S. pneumoniae strains were fully susceptible to amoxicillin-clavulanic acid and ampicillin, with 9.0 and 2.6% being resistant to penicillin and ceftriaxone, respectively. The ratios of resistant strains to tetracycline, co-trimoxazole, and chloramphenicol were 73.7, 69.3, and 63.5%, respectively. Approximately 90% of strains remain sensitive to erythromycin. A high prevalence of resistance to the penicillins and cephalosporins does not exist in Trinidad, although a trend toward such a pattern appears to be developing. The most frequent serotype was 14 (37.8%), followed by 6B (20.0%), 23F (10.3%), and 4 (6.4%), and all were recovered from children. The other serotypes accounted for <6% of the total isolates. All penicillin- and ceftriaxone-resistant strains belonged to serotype 14 (MIC ≥ 2 μg/ml and ≥ 4 μg/ml), respectively. Identifiable risk factors for resistant isolates included the prevalence of otitis media and sinusitis among children treated inadequately with oral cephalosporins; the ease of obtaining antibiotics without a prescription at many pharmacies; and the indiscriminate prescribing of antibiotics by general practitioners.

The high degree of polymorphism of human leukocyte antigen (HLA) genes has been suggested to result from natural selection against susceptibility to a variety of infectious pathogens, including malaria. HLA molecules are considered to play a crucial role in the defense of the host against malarial infection, and different HLA class I and class II alleles have been reported to be associated with reduced susceptibility to malaria or severity of malaria in different populations. To test for associations between HLA alleles and severity of malaria in a Thai population, polymorphisms of HLA-B and HLA-DRB1 genes were investigated in 472 adult patients in northwest Thailand with Plasmodium falciparum malaria. In this study, malaria patients were classified into three groups: mild malaria, non-cerebral severe malaria, and cerebral malaria. Our results revealed that the allele frequencies of HLA-B46, -B56, and -DRB1*1001 were statistically different between non-cerebral severe malaria and cerebral malaria (P = 0.005), between mild malaria and cerebral malaria (P = 0.032), and between mild malaria and non-cerebral malaria (P = 0.007). However, our results may be showing false positives due to multiple testing. Thus, further study with a larger sample size must be conducted to obtain conclusive evidence of the association of these HLA-B and DRB1 alleles with severity of malaria in Thailand.

A case of rarely encountered Salmonella Typhi septic arthritis of the hip in a child with no preexisting disease is reported. Salmonella etiology was not suspected in this case, and the diagnosis was made only after bacterial isolation. Arthrotomy was done as an initial mode of management, followed by intravenous ciprofloxacin therapy to which the child responded favorably.

Yersinia enterocolitica biotype 1A isolates are increasingly being associated with diarrhea. However, the mechanism of their pathogenicity is not well understood. In the present study interaction of Y. enterocolitica isolates with CHO cells, HEp-2 cells, and J774 mouse macrophages was studied. Y. enterocolitica biotype 1A strains of clinical origin invaded CHO and HEp-2 cells to a significantly higher degree than non-clinical isolates. However, among non-clinical isolates, Y. enterocolitica strains of swine origin showed significantly more invasion in CHO and HEp-2 cells than water isolates. Y. enterocolitica isolates from clinical samples exhibited a greater level of survival in macrophages than isolates from non-clinical sources. It may be construed that Y. enterocolitica biotype 1A isolates of clinical and swine origin have higher virulence potential than those from other sources.

We report the case of a 73-year-old female patient with diabetic nephropathy and cholelithiasis. She was admitted to our hospital with right upper abdominal pain, nausea, and vomiting. The patient had visited an outpatient clinic with the same complaints 2 days earlier, and had been prescribed antibiotics empirically (two doses ofloxacin orally). Blood cultures taken before the start of antibiotic treatment in our hospital were negative. The patient was treated with parenteral ampicillin/sulbactam + ciprofloxacin empirically. The empiric antibiotic treatment was discontinued after 7 days. Elective cholecystectomy was performed after her general condition improved. An aerobic chocolate agar culture of the cholecystectomy material yielded Haemophilus influenzae type b. On postoperative day 3 the patient developed fever again. The fluids collected after cholecystectomy were evaluated microbiologically. H. influenzae type b was isolated from the samples and blood cultures. The patient was diagnosed with H. influenzae cholecystitis, and recovered after10-day treatment with ampicillin/sulbactam + ciprofloxacin. The findings are discussed together with references for differential diagnosis. H. influenzae cholecystitis due to cholelithiasis, although rare, should be considered in elderly patients with a history of chronic diseases such as diabetes mellitus or nephropathy.

A rapid screen was developed for the detection of imipenem-resistant Acinetobacter baumanii (IRAb) following a recent outbreak in the Surgical Intensive Care Unit (SICU) of a hospital in Singapore. Antimicrobial solutions of imipenem ranging from 16 mg/L to 64 mg/L were prepared in-house. Each of the antimicrobial solutions was then incorporated singularly into MacConkey agar plates by two different methods. One of the methods involved preparing MacConkey agar plates in-house and then adding the antimicrobial solution before the agar solidified (AS method). In the second method, 1 ml of the antimicrobial solution was poured onto the surface of the agar plate (LAS method). Fifty hand-nutrient broth washes of medical staff working in the SICU, Medical Intensive Care Unit, Medical Rehabilitation Ward, and Surgical Rehabilitation Ward were inoculated onto the two types of agar media. Two strains of IRAb were isolated from the hands. The LAS plates showed faster bacterial growth of resistant pathogens by about 24 h, and their detection was easier because susceptible bacteria were inhibited by the antimicrobial. The LAS method incorporating imipenem at 32 mg/L is recommended for the rapid screening of resistant pathogens in the routine clinical laboratory.

The purpose of our study was to investigate the suitability of throat gargling with sterile saline as an alternative method to throat swabs for detection of group A beta-hemolytic streptococcus (GAS). Throat specimens were obtained from 601 cases belonging to different age groups. Sterile Dacron swabs and gargle residue were first streaked on the side of a 5% sheep blood agar plate to which a 0.04 U bacitracin disk had been applied, and then 1.25 mg trimethoprim and 23.75 mg sulphamethoxazole were added to the plate. After incubation, beta-hemolytic colonies were classified serologically by latex agglutination. GAS was detected in both throat swabs and throat gargle specimens in 49 cases, but GAS was also detected in 12 throat swabs from patients with culture-negative gargles and in 8 gargle specimens from subjects in whom throat swabs were culture negative. The strength of agreement was evaluated by calculating the kappa coefficient (K = 0.82, P = 0.000). The sensitivity, specificity, positive predictive value, and negative predictive value of throat gargle specimens were 80.3, 98.5, 85.9, and 97.8%, respectively. Although the conventional throat swab culture remains the gold standard, the throat gargle method is a quick, safe, and easy method for detection of GAS that serves as an effective alternative to throat swab culture.

The present study examined the use of antibiotics with respect to the rate of Chlamydia trachomatis positivity. Our subjects were 282 sexually active Turkish females between the ages of 15 and 42. Endocervical samples were investigated in 60 women with pelvic inflammatory diseases (PIDs), 90 infertile patients (IPs), 92 registered commercial sex workers (CSWs), and 40 intrauterine device (IUD) users. All samples were analyzed using direct immunofluorescence test techniques for the presence of C. trachomatis antigen, which was found in 12.7% of our subjects, with positive results as high as 26% in patients between 21 and 30 years of age. C. trachomatis positivity was found to be 16.6% in PID patients, 23.3% in IPs, and 5.4% in CSWs; however, it was not found among IUD users. The rate of positivity was highest in IPs, and lowest in registered CSWs (P < 0.05), who are periodically examined for the presence of sexually transmitted diseases, as required by Turkish authorities. Interestingly, the usage of therapeutic or prophylactic antibiotics such as tetracycline and ceftriaxon was found to be quite high among IUD users (90% use of tetracycline) and CSWs (100% use of both antibiotcs). Our results show that C. trachomatis positivity in the southeast region of Turkey is not significantly higher than that found in previous studies on sex workers of other countries. Additionally, our results indicate that the use of prophylactic antibiotics decreases the rate of chlamydial infection.

Fungal infections are among the major causes of morbidity in cancer patients. In order to optimize the treatment of such patients, it is critical to determine the type of fungus causing infection as well as its susceptibility to antifungals. This study was undertaken to the study resistance of Candida spp. isolated from blood cultures of cancer patients to ketoconazole (KET), fluconazole (FLU), amphotericin B (AmpB), and flucytosine (FCU). A modified NCCLS M 27-A method was used to evaluate the activity of the species. Of the 56 Candida albicans isolates, 7 (12.5%) were resistant to FLU (MIC ≥ 64 μg/ml), 6 (10.7%) were resistant to KET (MIC ≥ 64 μg/ml) and 3 (5.3%) were resistant to FCU (MIC ≥ 32 μg/ml). One (14.3%) of 7 C. parapsilosis isolates was resistant to FLU (MIC ≥ 64 μg/ml). One (33.3%) of 3 C. tropicalis isolates was resistant to KET (MIC ≥ 64 μg/ml). None of the C. guilliermondii or C. pelliculosa isolates was resistant to KET, FLU, AmpB, or FCU. Based on these results, AmpB is an effective antifungal agent that can be used against all Candida isolates.

Though generally curable, tuberculosis (TB) is becoming increasingly resistant to commonly used antibiotics. Drug-resistant and multidrug-resistant (MDR)-TB is a consequence of monotherapy, insufficient drug therapy and national TB control programs. The present study was designed to reveal the resistance to major antimicrobial drugs (isoniazid [INH], streptomycin [SM], ethambutol [EMB], and rifampicin [RIF]) of Mycobacterium tuberculosis isolated from the respiratory specimens of TB patients in Duzce, Turkey. A total of 62 TB patients (46 male, 16 female; age: 17 - 75 mean: 42 ± 15.9) were included in the study; 52 (83.8%) were new cases and susceptible to all anti-TB drugs, while 10 (16.2%) were previously treated cases. Antimicrobial susceptibility tests were performed by the proportion method in Löwenstein-Jensen medium. Fifty-two of the 62 (83.8%) isolated M. tuberculosis strains were found to be susceptible to all drugs, and 7 (11.3%), 5 (8%), and 3 (4.8%) were resistant to SM, INH, and RIF, respectively; 3 (4.8%) were MDR. There were no EMB-resistant strains. The results of this study show the presence of drug-resistant and MDR strains of TB at Duzce in the northwest part of Turkey.

To determine the bacterial etiology of lower respiratory tract infections (LRTIs) in Turkey, quantitative cultures of sputum were carried out. The major pathogens for LTRIs were found to be Haemophilus influenzae, followed by Streptococcus pneumoniae and Moraxella catarrhalis. Only 6.1% of the H. inlfuenzae and all strains of M. catarrhalis were β-lactamase producers. An E-test showed that 31.2% of the S. pneumoniae strains had an intermediate resistance to penicillin, and the remaining strains were susceptible; no fully resistant strains were detected.