Evaluation of pattern of bacterial contamination of outpatient department table surfaces in relation to cleaning and disinfection practices in a tertiary care hospital in Ahmedabad.

BACKGROUND: Outpatient department (OPD) table surfaces frequently touched by patients and health-care workers in hospitals harbor potential pathogens and may act as source of infectious agents. OBJECTIVES: This study aimed to determine the pattern of bacterial contamination of surfaces of OPD tables in relation to existing cleaning/disinfection practices. METHODS: The descriptive study was conducted during July 2018-September 2018. A total of 128 swabs were collected from 32 OPD table surfaces immediately after cleaning or disinfection and then at 30 min, 2 h, and 4 h interval after cleaning or disinfection. Type and concentration of cleaner or disinfectant, number of cleaning strokes on table, and time of last washing of cleaning cloth with detergent were also noted from each location. Isolation, identification, and antibiotic susceptibility testing of the isolates were performed by standard microbiological techniques. RESULTS: A total of 337 bacterial isolates were recovered from 126 samples. Multidrug resistant Staphylococci, Acinetobacter, Pseudomonas, Klebsiella, and Escherichia coli were isolated. The mean bacterial colony count increased with time (P < 0.0001). Hand rub use, cleaning of OPD table surfaces with disinfectant, and more number of strokes with cleaning cloth resulted in decrease in colony count of bacteria isolated. CONCLUSION: High bacterial contamination of frequently touched OPD table surfaces with variety of potential pathogens like Staphylococcus, Acinetobacter, Pseudomonas, Klebsiella, and E. coli was detected. Hand hygiene among health-care workers and regular and frequent cleaning and disinfection of OPD table surfaces are highly recommended to prevent cross-transmission.

Bladder Endometriosis: Management by Cystoscopic and Laparoscopic Approaches.

STUDY OBJECTIVE: Endometriosis of the urinary system accounts for less than 1% of all endometriosis, wherein bladder endometriosis is the most common. Bladder endometriosis is defined as endometriosis infiltrating the detrusor muscle and represents 85% of urinary tract endometriosis [1,2]. Segmental bladder resection/partial cystectomy is the bladder-preserving surgery and offers the complete removal of bladder endometriotic nodules [3,4]. Laparoscopic/robotic excision increases the chances of complete removal of nodules but may lead to inadvertent removal of excess bladder wall and increase the risk of complications, especially in cases of large lesions in close proximity to ureteric orifices. Thus, simultaneous laparoscopy and cystoscopy offers the most effective way of complete resection of bladder endometriotic nodules, relieving symptoms and minimizing intraoperative and postoperative complications and recurrence rates in patients [5-11]. This article with accompanying video describes the systematic approach and step-by-step surgical excision of a bladder endometriotic nodule in a patient with frozen pelvis. DESIGN: Step-by-step surgical excision of a bladder endometriotic nodule by simultaneous cystoscopy and laparoscopy. (Canadain Task Force classification: level III) SETTING: Jyoti Hospital and Minimum Invasive Surgery Center, Ahmedabad, India. PATIENT: A 41-year-old women, P2L2, presented with cyclical dysmenorrhea, dysuria, and chronic pelvic pain. Informed consent was obtained from the patient, and the local institutional board provided the approval. INTERVENTION: Simultaneous cystoscopy and laparoscopy. MEASUREMENTS AND MAIN RESULTS: A preoperative assessment was done with transvaginal ultrasonography with a partially full bladder that showed an intravesical 3-cm endometriotic nodule along with chocolate cysts of the ovary and adenomyosis of the uterus. A simultaneous cystoscopy by a urologist and laparoscopy by a gynecologist was performed. On cystoscopy the nodule was seen away from both the ureteric orifices. The nodule was marked cystoscopically with a monopolar needle and laparoscopically with bipolar scissors. Laparoscopy began with a full inspection of the abdomen, pelvis, and adhesions. Dissection started from the left round ligament, and both paravesical spaces were dissected gently, keeping the bladder partially full. Good uterine manipulation helped to delineate vaginal fornices during dissection. Dissection continued over the isthmus, and bladder was gently separated from the isthmus. The bladder was partially filled with methylene blue and intentionally cut opened to excise the demarcated bladder nodule with a monopolar hook, taking a disease-free margin of 5 mm [12]. Two stay sutures were taken at both the lateral angles of the bladder, and suture ends were brought outside the abdomen to facilitate closure of the bladder transversely. After mobilization of the bladder, both uterine vascular bundles were desiccated with bipolar and laparoscopic hysterectomy. Vaginal closure was done away from bladder stitches. The patient was discharged on day 3 with catheter and DJ stents. On day 21, 3-dimensional computed tomography cystogram showed adequate bladder volume. Catheter and DJ stents were removed, low-pressure cystoscopy showed a smooth stitch line with mucosa over it and no residual endometriosis. The patient was found to have no symptoms at the 2-year follow up. CONCLUSION: The video demonstrates the feasibility of simultaneous laparoscopic and cystoscopic approach for excision of a bladder endometriotic nodule. Marking the nodule by simultaneous cystoscopy and laparoscopy before excision helps in removing the disease completely and avoiding unnecessary normal bladder wall excision, thus reducing the risk of recurrence and resultant small bladder symptoms.

Microorganisms isolated from mobile phones and hands of health-care workers in a tertiary care hospital of Ahmedabad, Gujarat, India.

The mobile phones have become an inevitable part of life for communication everywhere. Hospital-acquired infections are causing increased morbidity and mortality of hospitalized patients. After getting approval from the institutional review board, a total of 300 samples from mobile phones and dominant hands of resident doctors, nurses, and support staff working in neonatal intensive care unit, pediatric intensive care unit, intensive care unit, and emergency ward were tested according to standard guidelines for culture. Of 300 samples tested, 144 (96%) mobile phones and 145 (96.66%) dominant hands showed contamination with one or more types of microorganisms. Monomicrobial organisms were recovered from 247 samples and polymicrobial organisms were isolated from 42 samples. Mobile phones and hands of helath care workers serve as a potential reservoir for hospital acquired infections as multi-drug resistant pathogenic bacteria as well as normal flora of skin were recovered.

COVID-19 Infection in Reproductive Age Group Females: Experience of a Tertiary Care Urban Teaching Hospital.

Background: The objective of this study was to find out the effect, course of disease and management of the COVID-19 infection in pregnant women and compare it with non-pregnant population. Method: This is a retrospective study done at Sardar Vallabhbhai Patel Institute of Medical Science and Research (SVPIMSR), Smt. NHL MMC, Ahmedabad, from April 1, 2020, to September 30, 2020. All COVID-19-positive patients were divided into two groups: group A was comprised of pregnant/postpartum and group B of non-pregnant patients. Result: A total of 709 women (Group A-205, Group B-504) were included in the study, In group A 90% of patients were asymptomatic, while in group B 48% asymptomatic patients. Group A had 5.9% and group B had 13.1% patients having comorbidities. In group A, smaller number of patients had raised inflammatory markers as compared to group B. Only 4% patients of group A showed significant changes on chest X-ray as compared to 16% in group B. Only 2.9% patients of group A required intensive care unit admission as compared to 10.31% patients of group B. Mean hospital stay of group A was 10.6 days, and that of group B was 12.1 days. Conclusion: In pregnancy, due to the physiological alterations in cardiovascular, respiratory and immune system, the pregnant women are vulnerable to infections. Although pregnancy is immunocompromised state, the severity of Coivd-19 disease is milder as compared to non-pregnant COVID-19-positive patients.

Antimicrobial Resistance Surveillance in Typhoidal Salmonella in Ahmedabad in an Era of Global Antimicrobial Resistance Surveillance Systems.

INTRODUCTION: India possibly carries the highest burden of antimicrobial resistant typhoidal salmonellae in the world. We report on the health-care ecosystem that produces data on antimicrobial resistance (AMR) testing and the resistance patterns of typhoidal Salmonella isolates in the city of Ahmedabad. MATERIALS AND METHODS: Through municipality records and internet searches, we identified 1696 private and 83 public laboratories in the city; 4 medical colleges, 4 health-care institution attached laboratories, and 4 corporate laboratories (CLs) were performing culture and antibiotic sensitivity testing (AST), but only 2 medical colleges and 1 CL shared their data with us. There was considerable variation in culturing and sensitivity testing methodology across laboratories. RESULTS: Out of 51,260 blood cultures, Salmonella isolates were detected in only 146 (0.28%). AST was conducted on 124 isolates, of which 67 (54%) were found resistant. Multidrug resistance was absent. Concurrent resistance to more than one antibiotic was very high, 88%, among the 67 resistant isolates. Ciprofloxacin resistance varied widely between the private and public sector laboratories. Notably, isolates from the private sector laboratory showed complete resistance to azithromycin. CONCLUSIONS: High resistance to ciprofloxacin and azithromycin observed in Ahmedabad may be due to the increased use of these two antibiotics in the public and private sectors, respectively. The need of the hour is to identify a representative sample of laboratories from both the public and the private sectors and encourage them to participate in the national AMR surveillance network.

Identification of prevalent dengue serotypes by reverse transcriptase polymerase chain reaction and correlation with severity of dengue as per the recent World Health Organization classification (2009).

Context: A definite link between distinct dengue serotypes and severe clinical manifestations has not been established yet. The WHO classification (2009) of dengue is more competent in diagnosing severe cases compared to traditional (1997) classification. Aims: This study aimed to identify prevalent dengue serotypes and to correlate the severity of dengue with the dengue virus (DENV) serotypes in target population as per the recent WHO classification (2009). Settings and Design: A retrospective comparative observational study was conducted from 1st January 2015 to 31st December 2015. Subjects and Methods: We tested 242 dengue NS-1 antigen ELISA-positive cases for serotyping by dengue reverse transcriptase-polymerase chain reaction (RT-PCR). Severity of each dengue case confirmed by RT-PCR was determined as per the recent WHO classification (2009). Results: On the basis of RT-PCR, dengue infection was confirmed in 135 (55.78%) patients. DEN-3 was the most common serotype found in 71 (52.6%) patients, followed by DEN-2 serotype with 44 (32.6%) patients. Nearly 2.22% cases of DEN-2 and 2.96% cases of DEN-3 serotype were having dengue with warning signs. Severe dengue was found in 2.22% cases of DEN-2 and 5.18% cases of DEN-3 serotypes. Thrombocytopenia, haemorrhagic manifestations and atypical presentations were found most commonly in DEN-3 followed by DEN-2 serotype. Coinfection with more than one serotype was observed in our study, with the most common coinfection pattern being DEN-2 and DEN-3 serotypes. Conclusions: DENV-3 and DENV-2 serotypes are prevalent in the region and are associated with a more serious clinical profile than other serotypes.

Analysis of fentanyl analogs and novel synthetic opioids in blood, serum/plasma, and urine in forensic casework.

In recent years an increasing number of novel opioids have appeared on the illicit drug market and have been linked to the growing opioid crisis in the United States. It is suspected that synthetic-opioid-related deaths are underestimated since many laboratories either use a screening method that is not specific and sensitive enough for these compounds or testing is not performed for fentanyl and its related analogs in general. We describe a method for the analysis of 19 of the most current novel opioid drugs quantitatively in whole blood and serum, and 17 analytes qualitatively in urine using solid phase extraction with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The limit of detection was determined to be at a minimum 0.25 ng/mL for beta-hydroxythiofentanyl, 0.05 ng/mL for butyryl/isobutyrylfentanyl, AH-7921, 2-furanylfentanyl, 4-ANPP, and U-47700; 0.025 ng/mL for MT-45, para-methoxybutyrylfentanyl, 4-methylphenethyl acetyl fentanyl, U-50488, acrylfentanyl, valerylfentanyl, and carfentanil; and 0.0125 ng/mL for para-fluorofentanyl, ortho-fluorofentanyl, para-fluorobutyrylfentanyl/FIBF, and alpha-methylfentanyl. The lower limit of quantitation was determined to be 0.1 ng/mL for all analytes except AH-7921, U-47700, U-50488 which were 0.05 ng/mL and beta-hydroxythiofentanyl which was 0.5 ng/mL. The method was validated successfully according to a Scientific Working Group in Forensic Toxicology (SWGTOX) compliant approach. This method was applied to the analysis of 2758 samples between October 2016 and September 2017. It was determined that 4-ANPP, furanylfentanyl, and carfentanil were the 3 most prevalent fentanyl related compounds detected: 56.1% of cases were positive for 4-ANPP, 44.5% were positive for furanylfentanyl, and 25.2% cases were positive for carfentanil.

Isolation of Aspergillus nidulans from a case of fungal rhinosinusitis: a case report.

A rare species i.e. A. nidulans is reported as a causative agent of allergic fungal rhinosinusitis in this study. It is an increasingly recognized type of chronic recurring hypertrophic sinus disease. There are more than 185 species of aspergillus and over 95% of all infections are caused by A. fumigatus, A. flavus and A. niger. A. fumigatus alone accounts for the large majority of cases of both invasive and non invasive aspergillosis. A young immunocompetent lady presented with bilateral nasal obstruction due to multiple polypoid mass at Sheth Vadilal Sarabhai General Hospital, Ahmedabad. Provisional diagnosis of sinonasal polyposis possibly due to fungal cause with infiltration in to nasal cavity was made. Bilateral functional endoscopic sinus surgery with polypectomy was done. The specimen was examined by standard methods and the fungus was identified as A. nidulans by slide culture.

Evaluation of concurrent malaria and dengue infections among febrile patients.

CONTEXT: Despite a wide overlap between endemic areas for two important vector-borne infections, malaria and dengue, published reports of co-infections are scarce till date. AIMS: To find the incidence of dengue and malaria co-infection as well as to ascertain the severity of such dengue and malaria co-infection based on clinical and haematological parameters. SETTING AND DESIGN: Observational, retrospective cross-sectional study was designed including patients who consulted the tertiary care hospital of Ahmedabad seeking treatment for fever compatible with malaria and/or dengue. SUBJECTS AND METHODS: A total of 8364 serum samples from clinically suspected cases of fever compatible with malaria and/or dengue were collected. All samples were tested for dengue NS-1 antigen before 5 days of onset of illness and for dengue IgM after 5 days of onset of illness. In all samples, malaria diagnosis was based on the identification of Plasmodium parasites on a thin and thick blood films microscopy. RESULTS: Only 10.27% (859) patients with fever were tested positive for dengue and 5.1% (434) were tested positive for malaria. 3.14% (27) dengue cases show concurrent infection with malarial parasites. Hepatomegaly and jaundice 37.03% (10), haemorrhagic manifestations 18.51% (5) and kidney failure 3.7% (1), haemoglobin <12 g/dl 100% (27) and thrombocytopenia (platelet count <150,000/cmm) 96.29% (26) were common in malaria and dengue co-infections and were much more common in Plasmodium falciparum infections. CONCLUSION: All febrile patients must be tested for malaria and dengue, both otherwise one of them will be missed in case of concurrent infections which could lead to severe diseases with complications.

Short chain fatty acids induce TH gene expression via ERK-dependent phosphorylation of CREB protein.

Butyrate modulates specific gene expression through various second-messenger signal transduction systems including activation of the PKA/cAMP pathway (Decastro, M., Nankova, B.B., Shah, P., Patel, P., Mally, P.V., Mishra, R., La Gamma, E.F., 2005. Short chain fatty acids regulate tyrosine hydroxylase gene expression through a cAMP-dependent signaling pathway, Brain Res. Mol. Brain Res. 142 28-38; Mally, P., Mishra, R., Gandhi, S., Decastro, M.H., Nankova, B.B., Lagamma, E.F., 2004. Stereospecific regulation of tyrosine hydroxylase and proenkephalin genes by short-chain fatty acids in rat PC12 cells, Pediatr. Res. 55 847-854). In the current report, we provide additional evidence that exposure to butyrate causes a rapid activation of the MAP kinase pathway, associated with increased phosphorylation of CREB. Under these conditions, no changes in relative amounts of CREB protein were observed by Western blot. Pre-treatment with the MAPK specific inhibitor (U0126) or the adenylate cyclase inhibitor dideoxyadenosine (ddA) abolished the butyrate-induced: (i) accumulation of TH mRNA, (ii) the phosphorylation of ERK1/2 as well as (iii) CREB phosphorylation. PC12 cells transfected with a TH promoter-luciferase reporter gene showed a robust induction in response to butyrate that was significantly reduced after co-transfection of either of two dominant-negative CREB expression vectors. Nuclear run-on assays demonstrated that butyrate increases endogenous TH gene transcription. We conclude that the initial steps of butyrate-induced gene activation are mediated through the CREB/CREB family of transcription factors which are coupled to both the MAP kinase and cAMP-dependent second messenger systems. Our data delineate a molecular mechanism through which short chain fatty acid's, their related drug-congeners (e.g., valproate) or even diet-derived butyrate (from fermentation of carbohydrates in the gut) can in principle, modulate brain catecholaminergic systems by modifying TH gene expression, dopaminergic levels and the corresponding animal behavior. These molecular relationships also offer a plausible explanation of how the well-recognized clinical effects of ketogenic diets can alter human behavior via the same central mechanisms.

Isolation of Vibrio mimicus from a case of acute diarrhoea--a case report.

Over a four months period (June to September, 2003) 111 stool samples from cases of acute diarrhoea were screened for Vibronaceae in department of microbiology, Smt. N. H. L. Municipal medical college, Ahmedabad. All the isolates were identified by standard laboratory technique. A total of 36 species belonging to Vibrionaceae were isolated. Phage typing of all these Vibronaceae were done at National Institute Of Cholera and Enteric Disease, Kolkata. Out of 36 isolates, 35 were Vibrio cholereae and only one was Vibrio mimicus. We report this case because of rare strain.

Short chain fatty acids regulate tyrosine hydroxylase gene expression through a cAMP-dependent signaling pathway.

Multiple intracellular and extracellular regulatory factors affect transcription of the tyrosine hydroxylase (TH) gene encoding the rate-limiting enzyme in the biosynthesis of the neurotransmitters dopamine, norepinephrine and epinephrine. Short chain fatty acids like butyrate are known to alter TH gene expression, but the mechanism of action is unknown. In this report, transient transfection assays identified the proximal TH promoter to contain sufficient genetic information to confer butyrate responsiveness to a reporter gene. Deletion studies and gel shift analyses revealed that the promoter region spanning the cAMP response element is an absolute requirement for transcriptional activation by butyrate. The branched short chain fatty acid valproate is used for seizure control in humans. Significantly, it has a similar aliphatic structure to butyrate, and it was found to have similar effects on TH in PC12 cells. Site-directed mutagenesis indicated that the effects of both fatty acids were mediated through the canonical CRE. Butyrate treatment also resulted in CREB phosphorylation without changing CREB protein levels. The increased phosphorylation of CREB correlated with accumulation of TH mRNA. The adenylate cyclase inhibitor dideoxyadenosine blocked both CREB phosphorylation and accumulation of TH mRNA. The data are consistent with the conclusion that butyrate induces post-translational modifications of pre-existing CREB molecules in a cAMP/PKA-dependent manner to alter TH transcription. These results support the role of butyrate as a novel exogenous regulatory factor in TH gene expression. Our data delineate a molecular mechanism through which diet-derived environmental signals (e.g. butyrate) can modulate catecholaminergic systems by affecting TH gene transcription.

Coinfection by Aspergillus and zygomycetes species in a case of acute rhinosinusitis.

Invasive mycotic infections can be effectively treated if rapid identification of fungus is obtained. We reported a case of coinfection by Aspergillus and Rhizopus sp. involving nose, paranasal sinuses, orbit, and brain in a 68-year-old known hypertensive male. He was presented to ENT OPD with history of fever and intermittent headache since fifteen days along with history of right-sided nasal obstruction and proptosis since seven days. CT scan of brain and paranasal sinuses showed findings of pansinusitis with cellulitic changes in right orbit. MRI confirmed the same along with features of intracranial extension with focal meningitis in right frontotemporal region. Laboratory parameters did not conclude much except for leucocytosis and hyponatremia. Patient was taken for endoscopic debridement from nose and paranasal sinuses, and tissue was sent for microbiological and histopathological examination. Minced tissue was processed, and after 48 hrs of incubation two types of growth were identified, one was yellowish, granular, and powdery consistent with Aspergillus sp., and another was cottony and woolly consistent with Rhizopus sp. LCB mount confirmed presence of Aspergillus flavus and Rhizopus arrhizus. Patient responded to therapy with IV amphotericin B and surgical debridement. On discharge patient's condition was good.

Atypical presentation of visceral leishmaniasis in a HIV-positive patient from a nonendemic area.

Visceral leishmaniasis (VL), though widely prevalent in India, is not seen in the Rajasthan where the dry, hot and arid climatic conditions create a hostile environment for the growth of the parasite or its vector, the sandfly. We present a case of VL in a patient co-infected with HIV from this region. A 34-year-old known case of a HIV-positive patient presented to the skin department of our hospital with multiple, nontender, erythematous, papulonodular lesions all over the body for 6 months with history of weight loss and low-grade fever. Important examination findings were pallor, inguinal lymphadenopathy and hepatosplenomegaly. Laboratory findings included anemia, leucopenia, hypergammaglobulinemia and altered leucocytes to erythrocyte ratio. Buffy coat examination and bone marrow aspirates showed the presence of leishman bodies inside monocytes and macrophages respectively as well as extracellularly also. The patient was treated with amphotericin B intravenously and responded well to the treatment.

Mycetoma: Nonvenereal perineal lesions.

Mycetoma is a chronic, granulomatous disease of the skin, and subcutaneous tissue, which sometimes involves muscle, bones, and neighboring organs. It is characterized by tumefaction, abscess formation, and fistulae with discharge of grains from sinuses. Mycetoma can be caused by various species of fungi (eumycetoma) and aerobic actinomycetes (actinomycetoma), which occur as saprophytes in soil or plants. A tentative diagnosis sufficient to initiate treatment may be made on the basis of grain color. For instance, melanoid grains are always caused by fungi and ochroid or pale grains by actinomycetes. Although this is not the thumbrule, there are exceptional reports too. As trauma favors infection, most lesions are on the foot and lower leg but they may occur anywhere on the body mimicking actinomycosis. However, lab investigations and culture are important tool to differentiate apart from the clinical picture. We are reporting atypical case with unusual site of presentation (perineum and thigh) of mycetoma.

Retained uterine fundus after vaginal hysterectomy.

We report a case of retained uterine fundus after vaginal hysterectomy that was subsequently removed at laparoscopy. The patient had undergone vaginal hysterectomy 8 years previously and came to our hospital with abdominal pain. Examination revealed a supravesical mass. Laparoscopy was performed and showed the uterine fundus with its cornual attachments. The mass was excised and sent for histopathologic analysis, which confirmed that it was uterine tissue. Retained uterine tissue or myoma tissue has been reported, usually after morcellation. However, to our knowledge, our case is only the second reported case of retained fundus after complete vaginal hysterectomy. Because of adhesions, it is possible that the uterus was not completely removed. In such cases, laparoscopic assistance is extremely useful.

Total laparoscopic hysterectomy for large uterus.

AIM: In this review, we assessed the feasibility of total laparoscopic hysterectomy (TLH) in cases of very large uteri weighing more than 500 grams. We have analyzed whether it is possible for an experienced laparoscopic surgeon to perform efficient total laparoscopic hysterectomy for large myomatous uteri regardless of the size, number and location of the myomas. DESIGN: Retrospective review (Canadian Task Force Classification II-1) SETTING: Dedicated high volume Gynecological laparoscopy centre. PATIENTS: 173 women with symptomatic myomas who underwent total laparoscopic hysterectomy at our center. There were no exclusion criteria based on the size number or location of myomas. INTERVENTION: TLH and modifications of performing the surgery by ligating the uterine arteries prior, myomectomy followed by hysterectomy, direct morcellation after uterine artery ligation. RESULTS: 72% of patients had previous normal vaginal delivery and 28% had previous cesarean section. Average clinical size of the uterus was 18 weeks (10, 32). The average weight of the specimen was 700 grams (500, 2240). The average duration of surgery was 107 min (40, 300) and the average blood loss was 228 ml (10, 3200). CONCLUSION: Total laparoscopic hysterectomy is a technically feasible procedure. It can be performed by experienced surgeons for large uteri regardless of the size, number or location of the myomas.

Roles for the human ATP-dependent Lon protease in mitochondrial DNA maintenance.

Human mitochondrial Lon is an ATP-powered proteolytic machine that specifically binds to single-stranded G-rich DNA and RNA in vitro. However, it is unknown whether Lon binds mitochondrial DNA (mtDNA) in living cells or functions in mtDNA integrity. Here, we demonstrate that Lon interacts with the mitochondrial genome in cultured cells using mtDNA immunoprecipitation (mIP). Lon associates with sites distributed primarily within one-half of the genome and preferentially with the control region for mtDNA replication and transcription. Bioinformatic analysis of mIP data revealed a G-rich consensus sequence. Consistent with these findings, in vitro experiments showed that the affinity of Lon for single-stranded DNA oligonucleotides correlates with conformity to this consensus. To examine the role of Lon in mtDNA maintenance, cells carrying an inducible short hairpin RNA for Lon depletion were used. In control and Lon-depleted cells, mtDNA copy number was essentially the same in the presence or absence of oxidative stress. However when oxidatively stressed, control cells exhibited an increased frequency of mtDNA lesions, whereas Lon-depleted cells showed little if any mtDNA damage. This suggests that oxidative mtDNA damage is permitted when Lon is present and prevented when Lon is substantially depleted. Upon oxidative stress, mIP showed reduced Lon binding to mtDNA; however binding to the control region was unaffected. It is unlikely that oxidative modification of Lon blocks its ability to bind DNA in vivo as results show that oxidized purified Lon retains sequence-specific DNA binding. Taken together, these results demonstrate that mtDNA binding is a physiological function of Lon and that cellular levels of Lon influence sensitivity to mtDNA damage. These findings suggest roles for Lon in linking protein and mtDNA quality control.