Incidence, Clinical Manifestation, Treatment Outcome, and Drug Susceptibility Pattern of Nontuberculous Mycobacteria in HIV Patients in Tehran, Iran.

BACKGROUND: Nontuberculous mycobacterial (NTM) infections have radically increased worldwide due to the increase in HIV infections. The disease activity increases with progressive immunodeficiency. METHODS: A total of 216 HIV seropositive patients suspected of having mycobacterial infection were recruited for this study. Clinical samples were collected from each patient and cultured on Lowenstein-Jensen media. Detection and species identification were simultaneously done using Reverse Blot Hybridization Assay System. Also, the minimum inhibitory concentrations (MIC) for each isolate were determined in 7H9 broth media for 10 antibiotics. RESULTS: In this study, 4 rapid and 4 slow-growing NTM species were isolated and identified. Mycobacterium fortuitum was the most common NTM species, 3/8 (37.5%), followed by Mycobacterium kansasii, 2/8 (25%). The cases were identified as pulmonary disease, 5/8 (62.5 %), disseminated infection, 2/8 (25%), and skin abscess, 1/8 (12.5%). M. chelonae and Mycobacterium avium were isolated from patients diagnosed with disseminated infection with treatment failure. The skin abscess was caused by infection with M. simiae. The results of the MIC testing were as follows: M. kansasii and M. fortuitum were susceptible to amikacin (AMK); M. avium to clarithromycin (CLA); M. fortuitum 2/3 (67%) to ciprofloxacin (CIP); 1/2 (50%) of M. kansasii isolates to CLA, and M. chelonae to rifampin (RIF), linezolid (LIN), AMK, and CIP at medium and high concentrations. CONCLUSION: AMK showed incredible in vitro activity against M. kansasii and M. fortuitum. Also, M. avium was susceptible to CLA, whereas M. simiae and M. chelonae were resistant to the tested drugs in this study.

Ciprofloxacin and Clinafloxacin Antibodies for an Immunoassay of Quinolones: Quantitative Structure⁻Activity Analysis of Cross-Reactivities.

A common problem in the immunodetection of structurally close compounds is understanding the regularities of immune recognition, and elucidating the basic structural elements that provide it. Correct identification of these elements would allow for select immunogens to obtain antibodies with either wide specificity to different representatives of a given chemical class (for class-specific immunoassays), or narrow specificity to a unique compound (mono-specific immunoassays). Fluoroquinolones (FQs; antibiotic contaminants of animal-derived foods) are of particular interest for such research. We studied the structural basis of immune recognition of FQs by antibodies against ciprofloxacin (CIP) and clinafloxacin (CLI) as the immunizing hapten. CIP and CLI possess the same cyclopropyl substituents at the N1 position, while their substituents at C7 and C8 are different. Anti-CIP antibodies were specific to 22 of 24 FQs, while anti-CLI antibodies were specific to 11 of 26 FQs. The molecular size was critical for the binding between the FQs and the anti-CIP antibody. The presence of the cyclopropyl ring at the N1 position was important for the recognition between fluoroquinolones and the anti-CLI antibody. The anti-CIP quantitative structure⁻activity relationship (QSAR) model was well-equipped to predict the test set (pred_R² = 0.944). The statistical parameters of the anti-CLI model were also high (R² = 0.885, q² = 0.864). Thus, the obtained QSAR models yielded sufficient correlation coefficients, internal stability, and predictive ability. This work broadens our knowledge of the molecular mechanisms of FQs' interaction with antibodies, and it will contribute to the further development of antibiotic immunoassays.

Life-Threatening Atypical Case of Acute Generalized Exanthematous Pustulosis.

Antibiotics are known to cause severe cutaneous adverse reactions, such as the rare acute generalized exanthematous pustulosis (AGEP). Unlike Stevens-Johnson syndrome or toxic epidermal necrolysis, AGEP is rarely life-threatening. Systemic involvement is not typical, and if present usually coincides with a mild elevation of the hepatic enzymes and a decrease in renal function. Hence, AGEP is known to have a good prognosis and to be life-threatening only in elderly patients or patients with chronic diseases. Herein, we report a case of AGEP in a young healthy male leading to systemic inflammatory response syndrome and to treatment in an intensive care unit after being treated with 5 different antibiotics. Initial symptoms were not indicative for AGEP and the patient's course of disease led promptly to critical cardiorespiratory symptoms and systemic inflammatory response syndrome. We assume that the administration of the 5 different antibiotics resulted in type IV allergy as well as secondary infection with Enterococcus faecium and Staphylococcus aureus, while the underlying periodontitis also contributed to the severity of this case.

Development of an immunochromatographic strip test for rapid detection of ciprofloxacin in milk samples.

A rapid, simple, and sensitive immunochromatographic test strip has been developed for testing residues of ciprofloxacin (CIP). A specific and sensitive monoclonal antibody (mAb) for CIP was generated by immunizing BALB/c mice with well-characterized CIP-Keyhole limpet haemocyanin. Under the optimized conditions, the cut-off limits of test strips for CIP were found to be 5 ng/mL in phosphate-buffered saline and 2.5 ng/mL in milk samples. Each test can be evaluated within 3 min. The cross-reactivities of the CIP test strip to enrofloxacin (ENR), norfloxacin (NOR), nadifloxacin (NDF), danofloxacin (DANO), pefloxacin (PEX), lomefloxacin (LOME), enoxacin (ENO), and sarafloxacin (SAR) were 71.4%, 71.4%, 66%, 50%, 33%, 20%, 12.5%, and 6.25%, respectively. The data indicate that the method is sensitive, specific, and has the advantages of simplicity and speed, therefore, this test strip is a useful screening method for the detection of CIP residues in milk samples.

Production of the broad specific monoclonal antibody against sarafloxacin for rapid immunoscreening of 12 fluoroquinolones in meat.

The objective of this study was to produce a generic antibody for immunoassay of fluoroquinolone drugs in meat. Two novel haptens of sarafloxacin were synthesized that were used to produce the monoclonal antibodies. The obtained monoclonal antibodies simultaneously recognized 12 fluoroquinolone drugs (sarafloxacin, diflocaxin, marbofloxacin, ofloxacin, ciprofloxacin, enrofloxacin, norfloxacin, pefloxacin, lomefloxacin, amifloxacin, enofloxacin and danofloxacin). After evaluation of different coating antigen/antibody combinations, a heterologous competitive indirect enzyme linked immunosorbent assay (ELISA) was developed to determine the 12 drugs. The crossreactivities to these analytes were in the range of 18%-113% and the limits of detection were in the range of 0.8-6.5 ng/mL depending on the compound. Eight fluoroquinolones licensed as veterinary drugs in China were fortified into blank chicken for ELISA analysis. The recoveries were in the range of 67.6%-94.6% with coefficients of variation lower than 12.4%. Therefore, this method could be used as a screen tool for routine monitoring of the residues of these fluoroquinolone drugs in animal derived foods.

Synthesis of novel haptens against ciprofloxacin and production of generic monoclonal antibodies for immunoscreening of fluoroquinolones in meat.

BACKGROUND: The residues of fluoroquinolone drugs in foods of animal origin are dangerous to the consumers. The objective of this study was to produce a generic monoclonal antibody for determination of fluoroquinolone residues in meat. RESULTS: Two novel haptens of ciprofloxacin containing a free amidogen group on the piperazinyl ring were synthesised that were used to produce the monoclonal antibodies. The antibodies obtained simultaneously recognised 12 fluoroquinolones (ciprofloxacin, enrofloxacin, norfloxacin, sarafloxacin, diflocaxin, danofloxacin, ofloxacin, marbofloxacin, pefloxacin, lomefloxacin, amifloxacin and enofloxacin). After evaluation of different coating antigen-antibody combinations, a heterologous competitive indirect ELISA was used to determine the 12 drugs. The cross-reactivities were in the range of 23-120% and the limits of detection were in the range of 1.0-4.5 ng mL(-1). Eight fluoroquinolone drugs licensed as veterinary drugs in China were fortified into blank chicken for analysis. The recoveries were in the range of 61.5-82.5% with coefficients of variation in the range of 7.5-15.2%. CONCLUSION: This method could be used as a rapid screening tool for routine monitoring the residues of these fluoroquinolone drugs in animal-derived foods.

A new application of scanning electrochemical microscopy for the label-free interrogation of antibody-antigen interactions: Part 2.

Within this paper we describe the use of scanning electrochemical microscopy (SECM) to fabricate a dotted array of biotinylated polyethyleneimine which was then used to immobilise first neutravidin and then a biotinylated antibody towards a relevant antigen of interest (PSA, NTx, ciprofloxacin). These antigens were selected both for their clinical relevance but also since they display a broad range of molecular weights, to determine whether the size of the antigen used effects the sensitivity of this approach. The SECM was then used to image the binding of both complementary and non-complementary antigens in a label-free assay. Imaging of the arrays before and following exposure to various concentrations of antigen in buffer showed clear evidence for specific binding of the complementary antigens to the antibody functionalised dots. Non-specific binding was also quantified by control experiments with other antigens. This demonstrated non-specific binding across the whole of the substrate, thereby confirming that specific binding does occur between the antibody and antigen of interest at the surface of the dots. The binding of ciprofloxacin was investigated both in simple buffer solution and in a more complex media, bovine milk.

Influence of hapten density on immunogenicity for anti-ciprofloxacin antibody production in mice.

To generate antibodies against small molecules, it is necessary to couple them as haptens to large carriers such as proteins. However, the immunogenicity of the conjugates usually has no linear correlation with the hapten-protein ratio, which may lead to large variations in the character of the desired antibodies. In the present study, ciprofloxacin (CPFX) was coupled to bovine serum albumin (BSA) in five different proportions using a modified carbodiimide method. The conjugates were characterized qualitatively by spectrophotometric absorption and electrophoresis methods. Mass spectrometry and the trinitrobenzene sulfonic acid method were adopted to assay the density of conjugates quantitatively. As a result, CPFX-BSA conjugates with various hapten densities (21-30 molecules per carrier protein) were obtained. After immunization in mice, ELISA tests showed that the antisera titer increased gradually with the increase of hapten density. The antibody obtained from the mice showed high sensitivity toward CPFX. These results revealed the relationship between hapten density and immunogenicity as well as an optimized conjugation approach for immunization purposes.

Nonirritant intradermal skin test concentrations of ciprofloxacin, clarithromycin, and rifampicin.

BACKGROUND: Intradermal skin testing of the clinically important antibiotics ciprofloxacin, clarithromycin, and rifampicin in the case of suspected allergies to antibiotics is poorly standardized. For clinical practice, standardized procedures and protocols are desired. METHODS: Fifteen healthy volunteers were tested with different concentrations of the antibiotics as well as with appropriate controls. Test readings included wheal area measured by digital image analysis and blood flow increase measured by laser Doppler flowmetry (LDF). To reduce interpersonal variability, test results were normalized with the individual controls using a novel protocol. RESULTS: Nonirritating concentrations of the three antibiotics (ciprofloxacin ~0.0067 mg/ml, clarithromycin ~0.05 mg/ml, rifampicin ~0.002 mg/ml) could be defined for healthy volunteers. Laser Doppler flowmetry generates comparable results to wheal area measurement. Normalization of the test results is necessary and can be applied in a practical algorithm. CONCLUSIONS: Standardized skin testing to detect sensitization to broadly used nonbetalactam antibiotics was presented and should be applied in truly sensitized patients. This approach should help to minimize the inter- and intraindividual differences in reactivity.

[Development of specific antibodies against ciprofloxacin].

AIM: To prepare specific antibodies against ciprofloxacin (CIP) and characterize the antibodies properities with ELISA, then lay the foundation for development of CIP rapid detection kit. METHODS: New Zealand white rabbits and BALB/c mice were immunized with CIP-cBSA conjugate, CIP-nOVA and CIP-cOVA serving as coating antigen were used to screen antisera, indirect (competitive) ELISA was developed to determine the titer and specificity of the antisera. RESULTS: Seven antisera against CIP were obtained, two of them were high specific to CIP with IC(50); 1 µg/L, the titer of which was 4 000 and 2 000, respectively.The antisera had some degree cross-reactivity with ENR, NOR and OFL, but had hardly cross-reactivity with PEN, KAN and QEN. CONCLUSION: The antibodies with high specificity developed in this study can be used to develop CIP detecting kit.

Preparation of high-affinity rabbit monoclonal antibodies for ciprofloxacin and development of an indirect competitive ELISA for residues in milk.

A convenient competitive enzyme-linked immunosorbent assay (ELISA) for ciprofloxacin (CPFX) was developed by using rabbit monoclonal antibodies (RabMAbs) against a hapten-protein conjugate of CPFX-bovine serum albumin (BSA). The indirect competitive ELISA of CPFX had a concentration at 50% inhibition (IC(50)) of 1.47 ng/ml and a limit of detection (LOD) of 0.095 ng/ml. The mAb exhibited some cross-reactivity, however, not so high with enrofloxacin (28.8%), ofloxacin (13.1%), norfloxacin (11.0%), fleroxacin (22.6%), and pefloxacin (20.4%). And it showed almost no cross-reactivity with other antibiotics or sulfonamides evaluated in this study. The competitive ELISA kit developed here could be used as a screening tool to detect and control illegal addition of CPFX in food products. This kit had been applied to milk detection and the recovery rates from samples spiked by CPFX were in a range of 63.02%-84.60%, with coefficients of variation of less than 12.2%.

Development of an immunoassay for ciprofloxacin based on phage-displayed antibody fragments.

The widespread use of ciprofloxacin in human, animal and plant health has raised an environmental problem, paralleled by several other antibiotics. The aim of this work is the development of a rapid and sensitive ELISA assay for ciprofloxacin, which can constitute an alternative to time-consuming HPLC methods. For this purpose, we worked with antibody fragments, instead of whole antibodies, and used magnetic beads as solid support. Ciprofloxacin was successfully immobilized onto this support with a carbodiimide-mediated reaction. A library of phage particles that express human single-chain antibodies at their surface was then screened with an optimized protocol. Several positive fragments were isolated and identified as being V(L) fragments. These were then fully characterized. A reproducible competitive ELISA was developed using the magnetic beads - ciprofloxacin as support and the phages displaying the V(L) fragment as recognition entity. This assay showed limits of detection and quantification of 9.3 nM and 33 nM, respectively. Also, competitive ELISAs with ciprofloxacin homologues and other molecules showed cross-reactivities lower than 12%.

Impedimetric immunosensor based on a polypyrrole-antibiotic model film for the label-free picomolar detection of ciprofloxacin.

This paper describes the construction of an impedimetric immunosensor for the label-free detection of ciprofloxacin, an antibiotic belonging to synthetic fluoroquinolones. A poly(pyrrole-N-hydroxysuccinimide) film was electrogenerated onto electrodes and then used for the reagentless covalent binding of a fluoroquinolone model bearing an amino group. The resulting electrodes were utilized to immobilize a layer of anticiprofloxacin antibody onto the polymer surface by immunoreaction. In presence of ciprofloxacin, the antibody was displaced in solution inducing marked changes in the impedance of the sensor electrodes. These phenomena were detected and characterized by electrochemical impedance spectroscopy allowing the selective detection of extremely low ciprofloxacin concentration, namely, 1 x 10(-12) g mL(-1) or 3 pmol L(-1). Sensors exposed to ciprofloxacin showed a decrease in the sum of the interfacial resistances with the increase in ciprofloxacin concentration from 1 x 10(-12) to 1 x 10(-6) g mL(-1).

Detection of fluoroquinolone antibiotics in milk via a labeless immunoassay based upon an alternating current impedance protocol.

This paper describes the construction of a labeless immunosensor for the antibiotic ciprofloxacin in milk and its interrogation using an ac impedance protocol. Commercial screen-printed carbon electrodes were used as the basis for the sensor. Polyaniline was electrodeposited onto the sensors and then utilized to immobilize a biotinylated antibody for ciprofloxacin using classical avidin-biotin interactions. Antibody loaded electrodes were exposed to solutions of antigen in milk and interrogated using an ac impedance protocol. The faradaic component of the impedance of the electrodes was found to increase with increasing concentration of antigen. Control samples containing a nonspecific IgG antibody were also studied but were found to display large nonspecific responses, probably due to the antibody binding some of the large number of components found in milk. Control sensors could, however, be fabricated using antibodies specific for species not found in milk. Calibration curves could be obtained by subtraction of the responses for specific and control antibody-based sensors, thereby eliminating the effects of nonspecific adsorption of antigen. Sensors exposed to ciprofloxacin in milk gave increases in impedance whereas ciprofloxacin in phosphate buffer led to decreases, indicating the possibility of developing sensors which can both detect and differentiate between free and chelated antigen.

Resistência da Neisseria gonorrhoeae a antimincrobianos em Manaus: período 2005-2006 / Neisseria gonorrhoeae antimicrobial resistance in Manaus: 2005-2006 period

Introdução: em 1998, a Fundação Alfredo da Matta, de Manaus, iniciou estudos para avaliar a resistência de isolados de N. gonorrhoeae aos antibióticos recomendados para o tratamento das uretrites e cervicites gonocócicas. Objetivo: verificar a resistência de isolados de Neisseria gonorrhoeae aos antibióticos penicilina, tetraciclina, azitromicina, ceftriaxona e ciprofloxacino no Laboratório de Bacteriologia Clínica da Fundação Alfredo da Matta, Manaus - Amazonas - Brasil. Métodos: neste estudo, avaliou-se a resistência de 110 gonococos à penicilina, à tetraciclina, à azitromicina, à ceftriaxona e ao ciprofloxacino pelo método de difusão com discos. Resultados: após os testes, verificou-se que 14,5% foram betalactamase positivos (PPNG) e a resistência à penicilina foi de 21,8%. Para a tetraciclina, 80,0% foram resistentes com 12,7% TRNG. Em relação à azitromicina, 8,2% dos isolados foram resistentes e não se detectou resistência ao ciprofloxacino e à ceftriaxona, porém 6,4% apresentaram sensibilidade reduzida ao primeiro e 5,5% diâmetro inferior a 33mm ao segundo. Conclusão: ao final, conclui-se que os altos percentuais de resistência à penicilina e tetraciclina são semelhantes aos observados em outros estudos realizados com cepas da região e sugerem que ainda há elevada pressão seletiva desses antibióticos sobre os gonococos. Os índices de resistência à azitromicina inviabilizam sua utilização como opção terapêutica. Tanto o ciprofloxacino quanto a ceftriaxona foram eficazes "in vitro", mas as taxas de sensibilidade reduzida de ciprofloxacino e os valores abaixo de 35 mm de diâmetro no antibiograma para a ceftriaxona, são indicativos da necessidade do monitoramento clínico e laboratorial constante desses medicamentos.

Fixed eruption caused by ciprofloxacin without cross-sensitivity to norfloxacin.

We report the case of a female patient who presented fixed exanthema following administration of ciprofloxacin. To our knowledge, only one case of fixed exanthema in response to this agent has appeared in the literature, and it was associated with cross-sensitivity to norfloxacin.