Enhancing chloramphenicol and trimethoprim in vitro activity by Ocimum sanctum Linn. (Lamiaceae) leaf extract against Salmonella enterica serovar Typhi

ObjectiveTo evaluate the antibacterial activity of Ocimum sanctum (O. sanctum) leaf extract, alone, and in combination with chloramphenicol (C) and trimethoprim (Tm) against Salmonella enterica serovar Typhi (S. typhi).MethodsThe antibacterial activity of ethanolic extract of tulsi, O. sanctum, leaf (TLE; 500 μg) for 23 S. typhi isolates was determined following agar diffusion. The C (30 μg) and Tm (5 μg) activity alone and in combination with TLE (250 μg) was determined by disk diffusion. The zone diameter of inhibition (ZDI) for the agents was recorded, and growth inhibitory indices (GIIs) were calculated.ResultsThe S. typhi isolates (n=23), which were resistant to both C (ZDI 6 mm) and Tm (ZDI 6 mm), had TLE (500 μg) ZDIs 16-24 mm. The ZDIs of C and Tm were increased up to 15-21 mm and 17-23 mm, respectively, when TLE (250 μg) was added to the C and Tm discs. The GIIs ranged 0.789-1.235 and 0.894-1.352, due to combined activity against S. typhi isolates, of C and TLE and Tm and TLE, respectively.ConclusionsThe data suggest that TLE, in combination with C and Tm, had synergistic activity for S. typhi isolates, and hence O. sanctum is potential in combating S. typhi drug resistance, as well promising in the development of non-antibiotic drug for S. typhi infection.     

Antimicrobial susceptibility profile of community acquired and nosocomial isolates of Escherichia coli from clinical blood culture specimens at a Nigerian university teaching hospital

ObjectiveTo ascertain the antibiotic susceptibility patterns of Escherichia coli recovered from blood culture specimens in Calabar, Nigeria.MethodsThe study was retrospective in nature and was carried out at University of Calabar Teaching Hospital (UCTH) Calabar. Data generated from blood culture specimens over a five year period (Feb. 2004-Feb. 2009) was compiled, relevant information such as age, sex, organism recovered and antibiotic susceptibility patterns were obtained from patients records. Samples were collected, transported, stored and processed using standard laboratory procedures. Data obtained was analysed using Epi Info 6 statistical software.ResultsEscherichia coli was responsible for 15.3% (31/203) of the blood infections being the third most common microorganism encountered. The community acquired (CA) isolates of the organism were significantly less resistant (P<0.05), compared to the nosocomial (NC) isolates against ampicillin, cloxacillin, amoxicillin, tetracycline, co-trimoxazole, chloramphenicol and erythromycin. The sensitivity of both the NC and CA isolates of Escherichia coli to amikacin, augmentin, ofloxacin, ciprofloxacin, ceftazidime, cefuroxime, ceftriaxone and rifampicin was generally high (80-100%) with no significant difference (P>0.05). Majority (>95.0%) of the NC isolates of Escherichia coli were resistant to six of the antibiotics tested.ConclusionsControl mechanisms for hospital acquired infections should be stepped up so as to limit the spread of the highly resistant bacterial strains. Also the sale and consumption of antibiotics by the public need to be regulated.     

Imported Enteric Fever: Case Series from the Hospital for Tropical Diseases,London, United Kingdom

Our current knowledge of the clinical characteristics of enteric fever is drawn mainly from population-based studies in disease-endemic countries, and there are limited data published on cases in returning travelers. We report the clinical characteristics of enteric fever in 92 travelers returning to London, United Kingdom. Salmonella typhi and S. paratyphi resulted in an almost indistinguishable clinical picture. Rose spots and relative bradycardia were found only in a few patients. A total of 91% of the patients had a normal leukocyte count, which was associated with a markedly increased level of alanine aminotransferase in 82%. A total of 57% of the S. typhi isolates had decreased susceptibility to ciprofloxacin and resistance to nalidixic acid; these isolates were from southern Asia. Thirty percent were multidrug resistant; all were from southern Asia and Nigeria. None of the paratyphoid isolates were multidrug resistant but rates of decreased susceptibility to fluoroquinolones were higher than in S. typhi (74%).     

Nosocomial and community acquired uropathogenic isolates of Proteus mirabilis and antimicrobial susceptibility profiles at a university hospital in Sub–Saharan Africa

ObjectiveTo ascertain antimicrobial susceptibility profile of Proteus mirabilis (P. mirabilis) from clinical urine specimens at a university hospital in the spate of its recorded increasing resistance patterns.MethodsThe study was retrospective in nature. Data generated from urine cultures of patients at University of Calabar Teaching Hospital for a period of five years (2004–2009) were compiled. Relevant information obtained were age and gender of patients, organisms recovered and their antibiotic susceptibility patterns. P. mirabilis was identified using standard laboratory procedures.ResultsP. mirabilis showed the highest resistance against ampicillin, cloxacillin, amoxicillin, tetracycline, co-trimoxazole, erythromycin and chloramphenicol (100%–37.2%) while colistin, ofloxacin, ciprofloxacin, ceftriaxone, nalidixic acid and nitrofurantoin recorded the highest activity (59.1%–96.9%) with no drug recording 100% activity. The resistance of the nosocomial isolates of the organism were significantly higher than the community acquired isolates against that of the common antibiotics in use (P<0.05).ConclusionsExtreme caution should be exercised in antibiotic administration in hospital setting and the potential benefits adequately assessed while control of nosocomial infections be given a priority so as to limit the spread of resistant bacteria.     

Determining of antibiotic resistance profile in Staphylococcus aureus isolates

ObjectiveTo determine the pattern of antibiotic resistance among Staphylococcus aureus (S. aureus) isolates from clinical specimens and to identify community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) in specimens that have been collected from patients referring to one of the hospitals of Ahvaz.MethodsS. aureus isolates from a hospital in Ahvaz were screened for resistance to various antibiotics including methicillin. The susceptibility of the isolates was determined by Kirby-Bauer disc diffusion method. The MRSA was also treated with ethidium bromide to find the origin of resistance.ResultsAmong the bacterial isolates, all of 11 S. aureus were resistant to methicillin and cefixime, 2 were resistant to ciprofloxacine, 6 were resistant to tetracycline and the reminder were sensitive or intermediate to other antibiotics. The treated isolates were reminded resistant to methicillin and this suggested that the plasmid was not the origin of resistance in these isolates.ConclusionsThese results showed that infection due to MRSA is widespread in Ahvaz and with respect to the spread of vancomycin resistance among MRSA and appearance of overwhelming infections. It is necessary to identify continuously the profile of antibiotic resistance among S. aureus isolates in other regions and finding appropriate antibiotic for infection control and eradication.     

Prospective multi-region study on primary antibiotic resistance of Helicobacter pylori strains isolated from Chinese patients

BackgroundLarge-scale multi-region studies are urgently needed to provide comprehensive and up-to-date information on the antibiotic resistance of Helicobacter pylori that is critical for selecting the most optimal eradication regimens.AimsTo determine the resistance patterns of Helicobacter pylori strains isolated from dyspeptic patients.MethodsThis is a prospective, multicentre, cross-sectional, observational study. Helicobacter pylori cultures were successful in 600 patients (never receiving eradication therapy) from Northern, Eastern, Middle, and Southern regions between 2008 and 2012. Resistance to amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin was determined by Epsilometer test.ResultsThe overall resistance rate was highest for metronidazole (403, 67.2%), followed by clarithromycin (225, 37.5%), levofloxacin (201, 33.5%), rifampicin (85, 14.2%), amoxicillin (41, 6.8%), and tetracycline (21, 3.5%). There were 16.3% isolates susceptible to all tested antibiotics, followed by mono-resistance (34.2%), double resistance (27.0%), triple resistance (16.8%), quadruple resistance (4.7%), quintuple resistance (0.7%) and sextuple resistance (0.3%). Independent factors influencing antibiotic resistance were gender (to levofloxacin), age (to levofloxacin), and endoscopic finding (to clarithromycin, metronidazole, and levofloxacin). Among the clarithromycin-resistant isolates, 75.6% and 48.0% were also resistant to metronidazole and levofloxacin, respectively.ConclusionsHelicobacter pylori resistance to commonly used antibiotics in China is a very serious issue, due to the high resistance rate and general multiple resistance.     

Multidrug-resistant and extended-spectrum beta-lactamase (ESBL)-producing Salmonella enterica (serotypes Typhi and Paratyphi A) from blood isolates in Nepal: surveillance of resistance and a search for newer alternatives.

OBJECTIVES: We evaluated the prevalence of multidrug resistance (MDR) and production of extended spectrum beta-lactamase (ESBL) by Salmonella enterica (serotypes Typhi and Paratyphi A) in a teaching hospital in Nepal. The MDR strains of S. enterica were also tested for susceptibility to newer antibiotics. METHODS: Blood cultures were obtained from 4105 patients with febrile illnesses. Isolates of S. enterica were serotyped and antibiotic susceptibility testing was carried out using disk diffusion (Kirby-Bauer) and E-tests. ESBL screening and phenotype confirmation were done following National Committee for Clinical Laboratory Standards (NCCLS) recommendations for Escherichia coli. RESULTS: A total of 541 isolates of S. enterica serotypes Typhi (47%) and Paratyphi A (53%) were grown. Twenty-eight isolates (5%) of S. enterica were resistant to two or more antibiotics (MDR isolates), with a greater prevalence among serotype Paratyphi A (7%). All ESBL producers (three isolates) were serotype Paratyphi A. Most of the MDR S. enterica showed reduced susceptibility to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, ofloxacin, and ciprofloxacin, and had good susceptibility to extended-spectrum cephalosporins and carbapenems. Among the fluoroquinolones, gatifloxacin demonstrated better in vitro activity compared to levofloxacin, ciprofloxacin, and ofloxacin. CONCLUSIONS: A greater prevalence of S. enterica serotype Paratyphi A with higher rates of multidrug resistance and ESBL production is concerning for natives as well as travelers in Nepal since the current typhoid vaccines do not provide protection against this serotype.     

Surveillance of infection status of drug resistant Staphylococcus aureus in an Indian teaching hospital

Objective

To access nosocomial and community accounts of multidrug resistant strains of Staphylococcus aureus (S. aureus) isolated by surveillance in a teaching hospital, over a period of 30 months.

Methods

Clinical samples from nosocomial sources, i.e., wards and cabins, intensive care unit (ICU) and neonatal intensive care unit (NICU) sources, as well as community or outpatient department (OPD) sources of a hospital were used for isolating strains of S. aureus resistant to methicillin/oxacillin and vancomycin, over a period, November 2009-April 2012.

Results

Of a total of 1 507 S. aureus isolates, 485 strains from community and 1 022 isolates were from nosocomial sources; Out of 485 (100%) OPD S. aureus isolates, 390 (80.41%) were MRSA strains. Similarly, from wards and cabins of 564 (100%) isolates, 461 (81.73%) strains were MRSA; whereas of 458 (100%) isolates obtained from ICU and NICU, 363 (79.25%) strains were MRSA. It was ascertained with χ²-tests of independence that MRSA strains were equally distributed in “community” or “wards and cabins” or “ICU and NICU” sources, alike rest other drug-resistant S. aureus strains. Antibiotic sensitivity patterns of isolated strains with 16 antibiotics were ascertained. Out of 390 (100%) MRSA strains isolated from OPD, 80 (20.51%) were vancomycin resistant (VRSA) and 173 (44.35%) strains were moderately sensitive to vancomycin or called, vancomycin intermediate strains (VISA). Similarly, from nosocomial sources, out of 461 (100%) MRSA isolates obtained from wards and cabins, 110 (23.86%) strains were VRSA and 208 (45.11%) were VISA strains, whereas out of 363 MRSA isolates obtained from ICU and NICU, 61 (16.8%) VRSA strains and 164 (45.17%) VISA strains were found. A progressive increase of percent values of drug resistance to 16 antibiotics used for antibiotic profiling revealed its subtle infection dynamics.

Conclusions

This study revealed the appalling state of occurrence of MRSA and VRSA in a resource-limited setting. A progressive increase of percent values of drug resistance to 16 antibiotics used revealed its subtle infection dynamics.     

Carcinoma of the Gallbladder—Is It a Sequel of Typhoid?

Gallbladder diseases, including carcinoma, are common in the northern part of India and so are Salmonella typhi infection and typhoid carrier state. This study was aimed to find out the association of typhoid carrier state in patients with cholelithiasis, carcinoma of the gallbladder, and controls. The three groups are comparable in age and sex composition. This is the first study of its kind from an area of high endemicity for both typhoid infection and carcinoma of the gallbladder. A case–control study was carried out to detect typhoid carrier state among the patients with biliary diseases and healthy controls, using indirect haemagglutination assay measuring antibodies against highly purified S. typhi Vi polysaccharide antigen. A significantly high Vi positivity was observed in patients with gallbladder carcinoma (29.4%) compared to controls (5%) (² = 6.325, P < 0.004, OR = 7.19) and patients with cholelithiasis (10.7%) (² = 5.066, P < 0.01, OR = 3.86). There is 8.47 times more risk of developing carcinoma of the gallbladder in culture-positive typhoid carriers than the noncarriers. The present study suggests the typhoid carrier state to be one of the possible mechanisms of gallbladder carcinogenesis.     

PCR identification and automated ribotyping of Pseudomonas aeruginosa clinical isolates from intensive care patients

Nosocomial isolates of Pseudomonas aeruginosa exhibit high rates of resistance to antibiotics, and are often multidrug resistant. P. aeruginosa clinical isolates (n = 56) were obtained from ICU patients in a hospital in Pakistan over a 3-y period. Antimicrobial susceptibility of the 56 P. aeruginosa clinical isolates was investigated using 7 antibiotics and the resistance rates were as follows: aztreonam (68% resistant), ceftazidime (67%), imipenem (66%), ofloxacin (59%), amikacin (56%), gentamicin (44%), and piperacillin-tazobactam (27%) (p < 0.01). In addition, 55% of the P. aeruginosa clinical isolates were resistant to 4 or more antibiotics. Imipenem-resistant strains were frequently associated with ceftazidime, ofloxacin, aztreonam, and more strikingly, amikacin resistance (p < 0.05). PCR (using P. aeruginosa-specific primers VIC1 + VIC2 and P1 + P2, respectively) was highly specific and sensitive, and was positive for all 56 P. aeruginosa isolates tested. Automated ribotyping was used to investigate the clonal diversity of the 56 P. aeruginosa isolates. Automated ribotyping indicated that the clinical isolates were clonally related and could be clustered into 4 major ribogroups based on their similarity index, with ribogroup II being the dominant one. The P. aeruginosa isolates in ribogroup II were correlated with their antibiotic resistance pattern and, interestingly, there seemed to be a gradual acquisition of multiple antibiotic resistance associated with the isolates within this group over time. The ribotyping data, together with the antibiotic resistance profile, provide valuable molecular epidemiology information for the control of hospital-acquired P. aeruginosa infections.     

Antimicrobial resistance patterns and prevalence of class 1 and 2 integrons in <Emphasis Type="Italic">Shigella flexneri</Emphasis> and <Emphasis Type="Italic">Shigella sonnei</Emphasis> isolated in Uzbekistan

Background

Shigella is a frequent cause of bacterial dysentery in the developing world. Treatment with effective antibiotics is recommended for shigellosis, but options become limited due to globally emerging resistance. One of the mechanisms for the development of resistance utilizes integrons. This study described the antibiotic susceptibility and the presence of class 1 and 2 integrons in S. flexneri and S. sonnei isolated in Uzbekistan.

Results

We studied 31 isolates of S. flexneri and 21 isolates of S. sonnei isolated in Uzbekistan between 1992 and 2007 for the susceptibility or resistance to ampicillin (Am), chloramphenicol (Cl), tetracycline (Te), co-trimoxazole (Sxt), kanamycin (Km), streptomycin (Str), gentamicin (Gm), cefazolin (Czn), cefoperazone (Cpr), cefuroxime (Cur), ceftazidime (Ctz), nalidixic acid (NA) and ciprofloxacin (Cip). Am/Str/Cl/Te and Am/Str/Cl/Te/Sxt resistance patterns were found most frequently in S. flexneri. Single isolates were resistant to aminoglycoside, quinolones and cephalosporins. The resistance patterns were different in the two species. Integrons were detected in 93.5% of S. flexneri (29/31) and 81.0% of S. sonnei (17/21) isolates. In addition, 61.3% of S. flexneri (19/31) isolates and 19.0% of S. sonnei (4/21) isolates carried both classes of integrons. In 29.0% of S. flexneri (9/31) isolates, only class 1 integrons were identified. In S. flexneri isolates, the presence of class 1 integrons was associated with resistance to ampicillin and chloramphenicol. Only Class 2 integrons were present in 61.9% of S. sonnei (13/21) isolates.

Conclusions

Our study documents antibiotic resistance among Shigella spp. in Uzbekistan. Ninety percent of Shigella strains were resistant to previously used antibiotics. Differences among S. flexneri and S. sonnei isolates in patterns of antimicrobial resistance to routinely used shigellosis antibiotics were observed. The majority of S. flexneri were resistant to ampicillin, chloramphenicol, tetracycline and streptomycin. Class 1 and 2 integrons were widely present in these Shigella strains. Resistance to ampicillin/chloramphenicol was associated with the presence of class 1 integrons. Though several mechanisms are possible, the resistance of Shigella isolates to ampicillin/chloramphenicol may be associated with the expression of genes within class 1 integrons.

     

济宁地区淋球菌临床分离株对抗生素的耐药性检测

琼脂平皿稀释法测定临床收集的100株淋球菌对青霉素的耐药率为97.0%,对氧氟沙星、多西环素和阿奇霉素的耐药率分别为89.0%、87.0%和63.0%,对头孢曲松和壮观霉素的耐药率为9.0%和6.0%。表明济宁地区淋球菌对常用抗生素的耐药性较严重。     

Gallstones play a significant role in Salmonella spp. gallbladder colonization and carriage

Salmonella enterica serovar Typhi can colonize the gallbladder and persist in an asymptomatic carrier state that is frequently associated with the presence of gallstones. We have shown that salmonellae form bile-mediated biofilms on human gallstones and cholesterol-coated surfaces in vitro. Here, we test the hypothesis that biofilms on cholesterol gallbladder stones facilitate typhoid carriage in mice and men. Naturally resistant (Nramp1^+/+) mice fed a lithogenic diet developed cholesterol gallstones that supported biofilm formation during persistent serovar Typhimurium infection and, as a result, demonstrated enhanced fecal shedding and enhanced colonization of gallbladder tissue and bile. In typhoid endemic Mexico City, 5% of enrolled cholelithiasis patients carried serovar Typhi, and bacterial biofilms could be visualized on gallstones from these carriers whereas significant biofilms were not detected on gallstones from Escherichia coli infected gallbladders. These findings offer direct evidence that gallstone biofilms occur in humans and mice, which facilitate gallbladder colonization and shedding.     

Characterization of gyrA and gyrB mutations and fluoroquinolone resistance in Mycobacterium tuberculosis clinical isolates from Hubei Province, China

ObjectiveThe study aimed to investigate gyrA and gyrB mutations in Mycobacterium tuberculosis (MTB) clinical strains from 93 patients with pulmonary tuberculosis in Hubei Province, China, and analyze the association between mutation patterns of the genes and ofloxacin resistance level.ResultsAmong 93 MTB clinical isolates, 61 were ofloxacin-resistant by the proportion method, and 32 were ofloxacin-susceptible MDR-TB. No mutation in the gyrB gene was found in any MTB strains. In the 61 ofloxacin-resistant isolates, 54 mutations were observed in the gyrA gene. Only one mutation in the gyrA gene was found in ofloxacinsusceptible MDR-TB isolates. In this study, the mutation patterns of gyrA involved seven patterns of single codon mutation (A90V, S91P, S91T, D94N, D94Y, D94G or D94A) and two patterns of double codons mutation (S91P &; D94H, S91P &; D94A). The ofloxacin minimal inhibitory concentrations (MICs) of three patterns of single codon mutations in the gyrA gene (codons 94, 90 and 91) showed a statistically significant difference (p < 0.0001).ConclusionsThe gyrA mutations at codons 90, 91 and 94 constitute the primary mechanism of fluoroquinolone resistance in MTB, and mutations at codon 91 in the gyrA gene may be associated with low-level resistance to ofloxacin.     

Salmonella enterica serovar Typhi plasmid pRST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy

ObjectivesPlasmid pR_ST98 is a hybrid resistance-virulence plasmid isolated from Salmonella enterica serovar Typhi (S. typhi). Previous studies demonstrated that pR_ST98 could enhance the virulence of its host bacteria. However, the mechanism of pR_ST98-increased bacterial virulence is still not fully elucidated. This study was designed to gain further insight into the roles of pR_ST98 in host responses.MethodsHuman-derived macrophage-like cell line THP-1 was infected with wild-type (ST8), pR_ST98-deletion (ST8-ΔpR_ST98), and complemented (ST8-c-pR_ST98) S. typhi strains. Macrophage autophagy was performed by extracting the membrane-unbound LC3-I protein from cells, followed by flow cytometric detection of the membrane-associated fraction of LC3-II. Intracellular bacterial growth was determined by colony-forming units (cfu) assay. Macrophage cell death was measured by flow cytometry after propidium iodide (PI) staining. Autophagy activator rapamycin (RAPA) was added to the medium 2 h before infection to investigate the effect of autophagy on intracellular bacterial growth and macrophage cell death after S. typhi infection.ResultsPlasmid pR_ST98 suppressed autophagy in infected macrophages and enhanced intracellular bacterial growth and S. typhi-induced macrophage cell death. Pretreatment with RAPA effectively restricted intracellular bacterial growth of ST8 and ST8-c-pR_ST98, and alleviated ST8 and ST8-c-pR_ST98-induced macrophage cell death, but had no significant effect on ST8-ΔpR_ST98.ConclusionsPlasmid pR_ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy.     

Identifying and elucidating the resistance of Staphylococcus aureus isolated from hospital environment to conventional disinfectants

BackgroundStaphylococcus aureus is a nosocomial pathogen, detection and elucidation of its resistance mechanisms to conventional disinfectants may aid in limiting its spread on environmental surfaces in health care settings. In the current study, disinfectant susceptibility of S. aureus strains isolated from the hospital environment as well as possible associations between the presence of disinfectant-resistance genes and reduced susceptibility to disinfectants was investigated.MethodsA total of 245 samples were collected from the hospital environmental surfaces. The minimum inhibitory (MIC) and bactericidal concentrations (MBC) of disinfectants against S. aureus isolates were determined using the micro-broth dilution method. The qac genes (qacA, qacE, and qacΔE1) were detected by PCR and confirmed by sanger sequencing.ResultsA total of 47 S. aureus strains were isolated, with more than 85% of them showing methicillin resistance. The qacA, qacE, and qac?E1 genes were found in 23.4%, 29.7%, and 4.2% isolates respectively. All the isolates with qac genes had higher MIC and MBC values to selected disinfectants.ConclusionsSignificant methicillin resistant S. aureus (MRSA) contamination in the hospital environment was detected. Furthermore, higher qac gene frequencies were found in MRSA isolates that also correlated with higher MIC/MBC values to different disinfectants. The study proposes that hospitals should develop policies to determine disinfectant MICs against the common environmental isolates to contain the spread of resistant strains.     

Molecular basis of virulence in clinical isolates of Escherichia coli and Salmonella species from a tertiary hospital in the Eastern Cape, South Africa

Background

Apart from localized gastrointestinal infections, Escherichia coli and Salmonella species are major causes of systemic disease in both humans and animals. Salmonella spp. cause invasive infections such as enteric fever, septicemia, osteomyelitis and meningitis while certain types of E. coli can cause systemic infections, including pyelonephritis, meningitis and septicemia. These characteristic requires the involvement of a myriad of virulence factors.

Methods

This study investigated the virulence factors of Escherichia coli and Salmonella species in clinical specimens from patients with diarrhoea presenting to health care centres in Oliver R. Tambo District Municipality, Eastern Cape Province, Republic of South Africa. Microbiology analysis involved the use of cultural and molecular techniques.

Results

Out of a total of 315 samples screened, Salmonella isolates were obtained in 119 (37.8%) of cases and these comprised: S. choleraesuis (6%), S. enteritidis (4%), S. eppendorf (1%), S. hadar (1%), S. isangi (8%), S. panama (1%), S. typhi (52%), S. typhimurium (25%) and untyped Salmonella spp. (2%). Among the Salmonella species 87 (73.1%) were invasive. Using molecular diagnostic methods, diarrheagenic E. coli were detected in 90 cases (28.6%): the greater proportion of this were enteroaggregative E. coli (EAEC) 37 (41.1%), enteropathogenic E. coli (EPEC) 21 (23.3%) and enterohemorrhagic E. coli (EHEC) 21 (23.3%). The predominant virulence gene among the diarrheagenic E. coli was EAEC heat-stable enterotoxin astA genes while the virulence genes identified in the Salmonella strains were 15 (12.6%) flic and 105 (88.2%) inv genes. The amino acid identity of the representative genes showed 95-100% similarity to corresponding blast searched sequence.

Conclusions

This study showed the diversity of virulence gene expression in two major enteric pathogens. S. typhi and enteroaggregative E. coli were the predominant enteropathogens in our study area with an indication that EAEC is endemic within our study population. It was observed among other things that some diarrheagenic E. coli isolated from apparently asymptomatic subjects expressed some virulence genes at frequency as high as seen in diarrheagenic cases. This study underlines the importance of understanding the virulence composition and diversity of pathogens for enhanced clinico-epidemiological monitoring and health care delivery.     

Paratyphoid fever– Emerging problem in South India

ObjectiveTo review the clinical profile and drug susceptibilities of Salmonella paratyphi A in a tertiary care hospital.MethodsRetrospective analyses of 113 patients with paratyphoid fever and 101 culture proven Salmonella paratyphi A infection were included in the study. The study extended over a period of 3 years (2006-2008). Diagnosis of patients were based on clinical features, serology and blood culture. The drug susceptibility testing of the isolates were performed by the disc diffusion method. Clinical presentation, laboratory parameters, susceptibility patterns of isolates, treatment and clinical response were studied.ResultsOf the 113 cases, 77 (68.4%) were males and 36 were females (32.8%), which included 2 pediatric patients. Fever was the most common symptom (100.0%) followed by loose stools (37.2%), headache (35.4%), myalgia (31.9%), pain abdomen (29.2%), dry cough (19.5%) and vomiting (13.3%). All patients were clinically cured. Majority of the isolates (46%) were resistant to cotrimoxazole in 2006, however they became 100% sensitive in 2007 and 2008. whereas the strains became 100% sensitive to ampicillin and chloramphenicol only in 2008. In 2006 the sensitivity of organisms to ciprofloxacin was 89% but in 2007 and 2008 there has been an increasing resistance to ciprofloxacin (46% and 86%) respectively. Surprisingly 3 isolates (8.1%) were resistant to ceftriaxone in 2006, showed 100% sensitivity in 2008. Common drugs used were ceftriaxone in 100 cases (88.4%) and ciprofloxacin in 13 cases (11.6%). One patient had relapse of paratyphoid fever after treatment with ciprofloxacin which responded to ceftriaxone.ConclusionsParatyphoid fever A is one of the emerging infections and a significant problem in India. An increasing resistance to fluoroquinolones is noted. Continuous monitoring of drug susceptibilities is mandatory in instituting appropriate therapy.     

江苏奶牛空肠弯曲菌和结肠弯曲菌流行状况及耐药性分析

目的了解江苏省奶牛空肠、结肠弯曲菌流行及耐药状况。方法采用多重PCR方法对10个奶牛场的产奶牛、育成牛和饲养环境进行空肠弯曲菌和结肠弯曲菌流行状况调查,采用琼脂扩散法测定分离株的耐药性。结果1531份样品中,119份空肠弯曲菌阳性,平均阳性率7.77%;3份结肠弯曲菌阳性,平均阳性率0.20%;空肠弯曲菌、结肠弯曲菌阳性率最高分别为30.91%、3.57%。在三类样品中,产奶牛空肠弯曲菌、结肠弯曲菌阳性率分别为5.02%、0.32%,育成牛空肠弯曲菌阳性率为8.70%、未检出结肠弯曲菌,环境样品空肠弯曲菌、结肠弯曲菌阳性率为10.28%、0.18%。35株奶牛空肠弯曲菌分离株对8大类21种抗生素高度敏感率的是:阿莫西林100%、阿齐红霉100%、链霉素97.14%、庆大霉素94.29%、红霉素91.43%、头孢噻肟82.86%、克林霉素82.86%;高度耐药率的是:头孢哌酮100%、恩诺沙星100%、环丙沙星97.14%、复方新诺明97.14%、左旋氧氟沙星94.29%、萘啶酸94.29%、头孢拉定94.29%、诺氟沙星91.43%、头孢克罗88.57%。菌株耐药谱显示,35株分离株的耐药主要集中在9耐到12耐,占88.57%,产奶牛分离株的多重耐药性较其它分离株更严重。结论我国奶牛群中空肠弯曲菌、结肠弯曲菌的流行和耐药状况呈现多样化和复杂化,研究结果为正确评价我国奶牛群弯曲菌的流行状况和制定切实可行的防控措施提供科学依据。     

Insight into multidrug-resistant microorganisms from microbial infected diabetic foot ulcers

AimThis study was undertaken to inspect the preponderance of multidrug-resistant (MDR) microorganisms in microbial infected diabetic foot ulcers (DFUs) in north Egypt. Moreover, their later impact on the patients and previous antibiotic therapies were taken into consideration.MethodsTo accomplish this goal, twenty-two of diabetic foot patients with purulent wounds were enrolled in this prospective study. These wounds were swabbed and the antibiotics susceptibility patterns of most virulent bacteria and yeast were studied. Furthermore, bacterial and yeast strains were identified using 16S rRNA and 16S rRNA nucleotide sequences, respectively, and following their phenotypic characteristics employing the VITEK 2 system.ResultsMicrobial profiles showed a predominance of monomicrobial infections (77.3%), while polymicrobial infections were found in 22.7%. A total of 24 bacterial isolates (15 Gram-positive and 9 Gram-negative) and four yeast isolates were perceived. Four bacteria were selected based on their resistance toward more than six of empirical antibiotics. They were identified and deposited in GenBank as Acinetobacter baumanni MT3 (KY421195), Staphylococcus aureus MT1 (KY421197), Klebsiella pneumonia MT2 (KY421196), and Staphylococcus aureus MT4 (KY421198). On the other hand, one strain belonged to yeast was opted and identified as Candida albicans MT5 (MG851796).ConclusionThese findings might effectively help to avert the severe complications of diabetic foot infections (DFIs) besides our endeavours to find new antimicrobial wound dressings.